FIELD 5 [0001] The present disclosure relates to the field of wireless communication technology, and in particular to a wireless communication system and a device and a method in the wireless communication system, which implement a two-stage channel estimation and feedback scheme and a two-step pre-coding scheme that are adapted to an antenna array. 10 BACKGROUND [0002] A massive Multi-input Multi-output (MIMO) system attracts wide attention from the academia and the industry in recent years. The theoretical study shows that the massive MIMO system can significantly improve spectrum efficiency and energy efficiency of the system with simple linear detection and pre-coding algorithms, for example Zero Forcing (ZF) 15 algorithm, Minimum Mean Square Error (MMSE) algorithm and the like, thus the massive MIMO is likely to be adopted as key technology for a next generation communication standard. [0003) In an actual system, there are a series of problems to be solved in the massive MIMO technology. In theoretical study of the massive MIMO, generally it is assumed that a 20 base station adopts a linear array with a uniform spacing, i.e., antennas are placed in only a horizontal direction. In a case that the number of antennas is great, the linear array will result in that an antenna scale of the base station is too large and is difficult to be realized. One of solutions to the problem is to adopt a 3D-MIMO system in which antennas are placed in both a horizontal direction and a vertical direction. For the 3D-MIMO system, degrees of freedom 25 (related to the number of antennas in the horizontal direction and the vertical direction) in both the horizontal direction and the vertical direction can be utilized, thereby reducing the scale of the antenna array effectively. In addition, an extra degree of freedom in the vertical direction can be used to weaken interference between users and reduce interference between cells and so on, and hence the system performance can be improved to a certain degree. Due 30 to these advantages, the 3D-MIMO technology attracts attention from the industry, and is likely to be incorporated into the existing wireless communication standard. Sony China Ref.: CNPAI5002!NOO Sony Ref.: please provide Unitalen Ref.: OPI715-06-1042 Original [0004] Since the user equipment has liruited feedback accuracy, accurate channel status information can not be obtained using the existing channel estimation and feedback schemes, and the system performance can not be improved effectively. s SUMMARY [0005] A brief summary of the disclosure will be g1ven below to provide basic nnderstanding of some aspects of the disclosure. However, it shall be appreciated that this summary is neither exhaustively descriptive of the disclosure nor intended to defme essential or important components or the scope of the disclosure but is merely for the purpose of 10 presenting some concepts of the disclosure in a simplified form and hereby acts as a preamble of more detailed descriptions which will be presented later. [0006] In view of the above problems, an object of the present disclosure is to provide a wireless communication system and a device and a method in the wireless communication system, which implement a two-stage channel estimation and feedback scheme and a 15 corresponding pre-coding scheme, which are adapted to an antenna array, improve the system performance and reduce operation complexity. [0007] According to an aspect of the present disclosure, a device in a wireless communication system is provided, which includes: a channel information acquiring unit configured to acquire first channel information on a channel between a first communication 20 apparatus and a second communication apparatus; a pre-coding unit configured to pre-code a first reference signal based on the first channel information; a measurement configuration information generating unit configured to generate measurement configuration information for the second communication apparatus, the measurement configuration information including a measurement indication for the pre-coded first reference signal; and a controlling 25 nnit configured to. control data signal transmission based on second channel information, which is fed back for the pre-coded first reference signal by the second communication apparatus according to the measurement configuration information. [0008] According to a preferred embodiment of the present disclosure, the pre-coding unit may be further configured to ._pre-code the first reference signal further based on channel 30 information related to other connnunication apparatus. -2- Sony China Ref.: CNPA15002!NOO Sony Ref.: please provide UnitalenRef.: OP1715-06-1042 Original [0009] Accorcling to a preferred embodiment of the present disclosure, the controlling unit may be further configured to control the data signal transmission further based on channel information related to other communication apparatus. [0010] According to a preferred embodiment of the present disclosure, the channel 5 information acquiring unit may be configured to acquire the first channel information of multiple second communication apparatuses, and the device may further include: a determining unit configured to determine, based on the first channel information of each of the multiple second communication apparatuses, whether the first communication apparatus is to send the pre-coded first reference signal to a corresponding second communication 10 apparatus. Preferably, the pre-coding unit may be further configured to pre-code, based on a determination result of the determining unit, the first reference signal for the frrst channel information of one or more of the multiple second communication apparatuses. (0011) According to a preferred embodiment of the present disclosure, the pre-coding unit may be configured to calculate, for the first channel information of one or more of the 15 multiple second communication apparatuses, pre-coding matrixes of corresponding second communication apparatuses, and pre-code the first reference signal utilizing superposition of the pre-coding matrixes. [0012] According to a preferred embodiment of the present disclosure, the pre-coding unit may be configured to calculate, for the first channel information of one or more of the 20 multiple second communication apparatus, pre-coding matrixes of corresponding second communication apparatuses, and pre-code the first reference signal utilizing the pre-coding matrixes respectively. Preferably, the device may be configured to allocate different code words, time or frequency resources to the first reference signal for one or more of the multiple second communication apparatuses so as to perform multiplexing. 25 · · [0013] According to a preferred embodiment of the present disclosure, the device may further include: a radio resource allocating unit configure to allocate, based on the first channel information, radio resources for transmission of the pre-coded first reference signal or a data signal. [0014) According to a preferred embodiment of the present disclosure, the channel 30 information acqui1ing unit may be further configured to acquire feedback information for a second reference signal· of the second communication apparatus as the first channel - 3 - information. Sony China Ref.: CNPA 15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original [0015] According to a preferred embodiment of the present disclosure, the second reference signal may be transmitted on only a part of antennas in an antenna array of the first communication apparatus. 5 [0016] According to a preferred embodiment of the present disclosure, the device may further include: a beamforming unit configured to perform static/semi-static beamforming on the second reference signal. Preferably, the chatmel information acquiring unit may be further configured to acquire feedback information for the beamformed second reference signal of the second communication apparatus as the first charmel information. 10 [0017] According to a preferred embodiment of the present disclosure, the first reference signal may be a narrowband signal, and the second reference signal may be a wideband signal. [0018] According to a preferred embodiment of the present disclosure, a transmission cycle of the first reference signal may be shorter than that of the second reference signal. 15 [0019] According to a preferred embodiment of the present disclosure, the charmel information acquiring unit may be further configured to acquire the first channel information by performing charmel estimation according to a third reference signal from the second communication apparatus. [0020] According to a preferred embodiment of the present disclosure, the third reference 20 signal may be an uplink sounding reference signal. [0021] According to a preferred embodiment of the present disclosure, the first communication apparatus may be a base station, the second communication apparatus may be user equipment, the device may be located at the base station end, and the device may further include: a transceiving unit configured to perfonn signal transceiving between the base station 25 and the user equipment. [0022] According to a prefened embodiment of the present disclosure, the first channel information may be channel information in a first dimensional direction, and the second channel information may be channel information in a second dimensional direction. [0023] According to a preferred embodiment of the present disclosure, the first dimensional 30 direction may be an altitude direction, and the second dimensional directiorr may be an -4- angular direction. Sony China Ref.: CNPAI5002INOO Sony Ref.: please provide Unitalen Ref.: OPI715-06-1042 Original [0024] According to a preferred embodiment of the present disclosure, the first dimensional direction may be an angular direction, and the second dimensional direction may be an altitude direction. 5 [0025] According to a preferred embodiment of the present disclosure, the first channel information may be preliminary information on the channel, and the second channel information may be further information on the channel. [0026] According to another aspect of the present disclosure, a device in a wireless communication system is further provided, which includes: a measuring unit configured to I 0 measure, based on measurement configuration information for a second communication apparatus from a first communication apparatus, a pre-coded first reference signal from the first communication apparatus, the measurement configuration information including a measurement indication for the pre-coded first reference signal; and a feedback information generating unit configured to generate, based on measurement for the pre-coded first 15 reference signal, feedback information as second channel information on a channel between the first communication apparatus and the second communication apparatus, for the first communication apparatus to control data signal transmission. [0027] According to another aspect of the present disclosure, a device in a wireless communication system is further provided, which includes: a first generating unit configured 20 to generate a first pre-coding matrix according to first channel information on a channel between a first communication apparatus and a second communication apparatus; and a second generating unit configured to generate a second pre-coding matrix according to the first pre-coding matrix and second channel information on the channel; and a pre-coding unit configured to pre-code a data signal according to the first pre-coding matrix and the second 25 · preccoding matrix. [0028] According to another aspect of the present diSfclosure, a wireless communication system is further provided, which includes: a first communication apparatus configured to acquire first channel information on a channel between the first communication apparatus and a second communication apparatus, pre-code a first reference signal based on the first channel 30 information, generate measurement configuration information for the second communication apparatus, the meas~ement configuration information including a measurep:\ent indication for - 5 - Sony China Ref.: CNPA15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original the pre-coded first reference signal, and control data signal transmission based on second channel information, which is fed back for the pre-coded first reference signal by the second communication apparatus according to the measurement configuration information; and the second communication apparatus configured to: measure the pre-coded first reference signal 5 based on the measurement configuration information, and generate feedback information based on measurement for the pre-coded first reference signal as the second channel information. [0029] According to another aspect of the present disclosure, a method m a wireless communication system is further provided, which includes: a channel information acquiring 10 step of acquiring first channel information on a chaunel between a first communication apparatus and a second communication apparatus; a pre-coding step of pre-coding a first reference signal based on the first channel information; a measurement configuration information generating step of generating measurement configuration information for the second communication apparatus, the measurement configuration information including a 15 measurement indication for the pre-coded first reference signal; and a controlling step of controlling data signal transmission based on second channel information, which is fed back for the pre-coded first reference signal by the second communication apparatus according to the measurement configuration information. [0030) According to another aspect of the present disclosure, a method in a wireless 20 communication system is further provided, which includes: a measuring step of measuring, based on measurement configuration information for a second communication apparatus from a first communication apparatus, a pre-coded first reference signal from the first communication apparatus, the measurement configuration information including a measurement indication for the pre-coded first reference signal; and a feedback information 25 generating step of generating, based on measurement for the pre-coded first reference signal, feedback information as second channel information on a channel between the first communication apparatus and the second colnmunication apparatus, for the first communication apparatus to control data signal transmission. [0031] According to another aspect of the present disclosure, a method in a wireless 30 communication system is further provided, which includes: a first generating step of generating a first pre-coding matrix according to first channel information on a channel - 6- Sony China Ref.: CNPA 15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original between a first connnunication apparatus and a second connnunication apparatus; a second generating step of generating a second pre-coding matrix according to the first pre-coding matrix and second channel information on the channel; and a pre-coding step of pre-coding a data signal according to the first pre-coding matrix and the second pre-coding matrix. 5 [0032] According to another aspect of the present disclosure, an electronic apparatus is further provided, which includes one or more processors configured to perform the methods in the wireless connnunication system according to the present disclosure described above. [0033] According to other aspects of the present disclosure, computer program codes and a computer program product for implementing the methods of the present disclosure, and a 10 computer readable storage medium, on which the computer program codes for implementing the methods of the present disclosure are recorded, are further provided. [0034] According to embodiments of the present disclosure, in a wireless connnunication system installed with a massive antenna array, for example a massive 3D-MIMO system, by utilizing a two-stage channel estimation and feedback scheme and a corresponding pre-coding 15 scheme, it is possible to effectively eliminate interference, reduce operation complexity and improve system overall performance. [0035] Other aspects of embodiments of the present disclosure are given in the following parts of the description. In which, detailed illustration is used to sufficiently disclose preferred embodiments of the embodiments of the present disclosure rather than limit the present 20 disclosure. BRIEF DESCRIPTION OF THE DRAWINGS [0036] The disclosure can be better understood with reference to the detailed description given below in conjunction with the accomr,anying drawings, throughout which identical or 25 like reference signs denote identical or like components. The accompanying drawings together with the following detailed description are incorporated into and form a part of the specification and serve to further illustrate the preferred embodiments of the disclosure and to explain the principle and advantages of the disclosure by way of example. In the drawings: . [0037] Figure 1 shows a block diagram of a functional configuration example of a device in 30 a wirelessconnnunication system according to an embodiment of,the present disclosure; - 7 • Sony China Ref.: CNPA15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original [0038] Figure 2 shows a block diagram of another functional configuration example of a device in a wireless communication system according to an embodiment of the present disclosure; [0039] Figure 3 shows a block diagram of another functional configuration example of a 5 device in a wireless communication system according to an embodiment of the present disclosure; [0040] · Figure 4 shows a block diagram of another functional configuration example of a device in a wireless communication system according to an embodiment of the present disclosure; 10 [0041] Figure 5 shows a block diagram of a functional configuration example of a device in a wireless communication system according to another embodiment of the present disclosure; [0042] Figure 6 shows a block diagram of another functional configuration example of a device in a wireless communication system according to another embodiment of the present disclosure; 15 [0043] Figure 7 shows a block diagram of another functional configuration example of a device in a wireless communication system according to another embodiment of the present disclosure; [0044] Figure 8 shows a schematic diagram of an example of an interaction flow in a wireless communication system according to an embodiment of the present disclosure; 20 [0045) Figure 9 shows a schematic diagram of another example of an interaction flow in a wireless communication system according to an embodiment of the present disclosure; [0046] Figure 10 shows a block diagram of a functional configuration example of a device in a wireless communication system according to another embodiment of the present disclosure. 25 [004 7] Figure 11 shows a block diagram of a functional configuration example of a second generating unit in a device according to another embodiment of the present disclosure; [0048] Figure 12 shows a block diagram of a functional configuration example of a pre-coding unit in a device according to another embodiment of the present disclosure; ... [0049] Figure 13 shows a schematic diagram of an ex<\mple of an interaction flow in a - 8- Sony China Ref.: CNPA 15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original wireless communication system according to an embodiment of the present disclosure; [0050] Figure 14 shows a block diagram of a schematic structure of a wireless communication system according to an embodiment of the present disclosure; [0051] Figure 15 shows a flowchart of a process example of a method m a wireless 5 communication system according to an embodiment of the present disclosure; [0052] Figure 16 shows a flowchart of a process example of a method m a wireless communication system according to another embodiment of the present disclosure; [0053] Figure 17 shows a flowchart of a process example of a method in a wireless communication system according to another embodiment of the present disclosure; 10 [0054] Figure 18 is a block diagram of an exemplary structure of a personal computer as an information processing apparatus that may be adopted in an embodiment of the present disclosure; [0055) Figure 19 is a schematic diagram of a apparatus distribution example in a wireless communication system according to an embodiment of the present disclosure; 15 [0056] Figure 20 shows a schematic diagram of a comparison example of spectrum efficiency in a wireless communication system to which the conventional technology is applied and spectrum efficiency in a wireless communication system to which the technology of the present disclosure is applied; [0057] Figure 21 shows a schematic diagram of another comparison example of spectrum 20 efficiency in a wireless communication system to which the conventional technology is applied and spectrum efficiency in a wireless communication system to which the technology of the present disclosure is applied; [0058] Figure 22 shows a block diagram of a first example of a schematic ~,onflguration of an evolutional based station ( eNB) to which the technology of the present disclosure may be 25 applied; [0059) Figure 23 shows a block diagram of a second example of a schematic configuration of an eNB to which the technology of the present disclosure may be applied; and [0060] Figure 24 shows a block diagram of an example of a schematic configuration of a smartphone to which the technology of the present disclosure may be applied. - 9 - DETAILED DESCRIPTION OF THE EMBODIMENTS Sony China Ref.: CNPA150021NOO Sony Ref.: please provide Unital en Ref.: OP1715-06- I 042 Original [0061] Exemplary embodiments of the present disclosure will be described below in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all 5 the features of practical implementations are described in the specification. However, it is to be appreciated that numerous implementation-specific decisions shall be made during developing any of such practical implementations so as to achieve the developer's specific goals, for example, to comply with system- and business-related constraining conditions which will vary from one implementation to another. Moreover, it shall also be appreciated 10 that such a development effort might be very complex and time-consuming but may simply be a routine task for those skilled in the art benefiting from this disclosure. [0062] It shall further be noted that only those device structures and/or process steps closely relevant to the solutions of the disclosure are illustrated in the drawings while other details less relevant to the disclosure are omitted so as not to obscure the disclosure due to those 15 unnecessary details. [0063] Hereinafter embodiments of the present disclosure are described m detail m conjunction with Figure 1 to Figure 24. [0064] Before describing the embodiments of the present disclosure, a method for performing channel estimation and sending a reference signal in a 3D-M1MO system 20 according to the conventional technology is introduced briefly. [0065] Presently, in the 3D-MIMO system, a reference signal may be sent generally in the following two methods. A first method is full space channel pre-coding. This method does not need extra processing, and each physical antenna port corresponds to a reference signal for channel estimation. A disadvantage of the first method is that a large reference signal 25 overhead may be caused. A second method is a method for sending a reference signal based on a Kronecker product. Specifically, a group of horizontal antennas are selected to send a reference signal to obtain horizontal channel information, then another group of vertical antennas are selected to send a reference signal to obtain vertical channel information, and then orthogonal processing is performed on the horizontal channel information and the 30 vertical channel information. A disadvantage of the second method is that: a receiving level of user equipment is low since the reference sigl1al is sent in an omni-directional way, thereby - "1 () -· resulting in a low accuracy of channel estimation. Sony China Ref.: CNPA 1 5002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original [0066] In the technology of the present disclosure, it is considered to combine channel feedback information of multiple users and utilize a two-stage channel estimation and feedback scheme, to effectively increase a receiving level for a reference signal at user 5 equipment end, thereby obtaining more accurate channel status information and improving the system performance. [0067] Hereinafter a block diagram of a functional configuration exan1ple of a device at base station end in a wireless commmlication system according to an embodiment of the present disclosure will be described by referring to Figure I first. 10 (0068] As shown in Figure 1, a device 100 according to the example may include a channel information acquiring unit 102, a pre-coding unit 104, a measurement configuration information generating unit 106 and a controlling unit 108. Hereinafter functional configuration examples of respective mlits are described in detail respectively. In some embodiments, the respective mlits described above may be implemented by one or more 15 processors, without providing separated components. [0069] The channel information acquiring unit 102 may be configured to acqmre first channel information on a channel between a first communication apparatus and a second commmlication apparatus. [0070] Preferably, the first commtmication apparatus may be a base station, and the second 20 commmlication apparatus may be user equipment. Here, it should be noted that in the embodiment of the present disclosure, description is made by assuming that the first communication apparatus is a base station and the second communication apparatus is user equipment, but the present disclosure is not limited thereto. Alternatively, the first communication apparatus may be other infrastructures or user equip;nent having a 25 corresponding base station frmction, and the second communication apparatus may be a small base station or other infrastructures having a corresponding user equipment frmction. An object of the present disclosure is to determine a channel condition between commmlication apparatuses and thus perform processing such as appropriate pre-coding, resource scheduling and so on, so as to achieve efficient data communication between the commmlication 30 apparatuses. . 11 - ;i/ Sony China Ref.: CNPA 15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original [0071] Hereinafter two exemplary ways of acquiring first channel information by the channel information acquiring unit l 02 are described respectively. [0072] In one exemplary way, in a Frequency Division Duplexing (FDD) system, the channel information acquiring unit l 02 may be configured to acquire feedback information 5 for a second reference signal of the second communication apparatus as first channel information. [0073] Specifically, for example, the first communication apparatus (for example, a base station) may send a second reference signal (for example, a Channel Status Indicator-Reference Signal (CSI-RS), a Cell-Specific Reference Signal (CRS) or the like) to 10 the second communication apparatus (for example user equipment), and thus the user equipment may measure the second reference signal according to corresponding measurement configuration information (which may include a measurement indici;ltion for the second reference signal) and feed back a measurement result to the base station using for example a channel quality indication (CQI), a pre-coding matrix indication (PMI), a rank indication (RI) 15 or the like, as the first channel information reflecting a channel condition. An example in this case is described later by referring to a schematic diagram of an interaction flow shown in Figure 8. [0074] As an example, the second reference signal may be a reference signal (for example CSI-RS, CRS or the like) in an altitude direction (for example, a vertical direction), which is 20 adapted to a case where the number of user clusters in an angular direction (for example, a horizontal direction) is small, thereby increasing a receiving power for the reference signal of the user in the angular direction; in addition, in this case, the acquired first channel information is channel information in the vertical direction for example. However, it should be understood that, according to an actual distribution of the antenna array and the 25 communication .'<1pparatuses and an actual performance- requirement, :the second reference signal may also be a reference signal in the angular direction (for ~xample, a horizontal direction), which is adapted to a case where the number of user clusters in the altitude direction is small, thereby increasing a receiving power for the reference signal of the user in the altitude direction, which also applies to the technology described in the present disclosure. 30 [0075] Preferably, considering correlation between positions of antenna elements, the second reference signal may be .transmitted on only a part of antennas (for example, a certain - 12 - Sony China Ref.: CNPA150021NOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original group of antennas) in an antenna array of the first communication apparatus (for example, a base station), instead of being transmitted on all antenna elements, since in a case that a spacing between antenna elements is small, there is strong correlation between charmel coefficient vectors corresponding to different groups on the antenna array, effective 5 information for pre-coding can be obtained by estimating a channel coefficient corresponding to only one group of antennas .For example, the base station may obtain, by sending CSI-RS utilizing a column of antennas in the vertical direction, an estimation result for the charmel status in the vertical direction from the user equipment. In this way, resource requirement for the reference signal may be reduced. 10 [0076] As another example, the second reference signal may be not limited to a reference signal in a certain fixed direction. In this case, preferably, the second reference signal may be beamformed. Hence, in the example, the device 100 may further include a beamforming unit configured to perform a static/ semi-static beamforming on the second reference signal, which is different from a pre-coding process based on a code book. The charmel information 15 acquiring unit 102 may be further configured to acquire feedback information for the beamformed second reference signal of the second communication apparatus (for example, user equipment) as the frrst charmel information. It should be understood that, in this case, the acquired first charmel information may be preliminary estimation information on the charmel, for example, a rough channel direction of the user equipment is obtained. It should be 20 understood that, in a case of beamforming the second reference signal, the beamforrning may be performed within a relatively wide range (i.e., covering more user equipment) to obtain preliminary information on the channel. [0077] As another example, the second reference signal may cover a downlink bandwidth and have a relatively long transmission cycle. Specifically, the second reference signal may be 25 distributee uniformly or approximately uniformly on the whole bandwidth and cover the ', •• '" c ,, ,-- •• -"' • whole bandwidth. Accordingly, the user equipment feeds back long-terrn/wideband channel status information for the second reference signal as preliminary first channel information, for the base station to process the first reference signal covering a narrowband downlink bandwidth, thereby acquiring more accurate second channel information. 30 [0078] As another exemplary way, in a Time Division Duplexing (TDD) system, the channel information acqumng unit I 02 may be further configured to perform channel - 13- Sony China Ref.: CNPA 150021NOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original estimation according to a third reference signal from the second communication apparatus, so as to acquire the first channel information. Preferably, as an example, the third reference signal may be an uplink Sounding Reference Signal (SRS). [0079j Specifically, for example, the second conununication apparatus (for example, user 5 equipment) may send the third reference signal (for example, an uplink SRS) to the first communication apparatus (for example, a base station), and thus the base station may perform channel estimation according to the third reference signal to obtain the first channel information on the channel. A specific channel estimation method is the same as the method in the conventional technology, which is not described in detail here. An example in this case 10 is described in detail later by referring to a schematic diagram of an interaction flow shown in Figure 9. [0080] In sununary, in an example in which the first communication apparatus is a base station and the second communication apparatus is user equipment, the base station may send a downlink reference signal which is not pre-coded, and then acquire a channel status 15 information report obtained by measuring the downlink reference signal by the user equipment, to determine preliminary downlink channel status information. Alternatively, based on reciprocity between uplink/downlink channels, the base station estimates preliminary downlink channel status information by receiving the uplink reference signal from the user equipment 20 [0081] The pre-coding unit 104 may be configured to pre-code the first reference signal based on the first channel information. For example, pre-coding is performed such that the first reference signal is transmitted in a certain direction or on a certain beam. Preferably, the pre-coding method may be pre-coding not based on a code book, for example ZF pre-coding, and MMSE pre-coding, to enhance a receiving level for the first reference signal of the user ·· ... .25 equi1'rnent. Alternatively, the pre-coding method may alsc,, be pre-coding based on a code book [0082] In a case that the first channel information is channel information in an altitude direction (for example a vertical direction), the first reference signal may be a reference signal (for example a CSI-RS, CRS or the like) in an angular direction (for example, a horizontal 30 direction), and the pre-coding process may be pre-coding in a ve1iical direction, aiming to improve a receiving'! eve! for the reference signal in the horizontal direction of user equipment . 14- Sony China Ref.: CNPA15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original at different altitudes. As compared with the second reference signal, the first reference signal may be transmitted on all antenna elements. [0083] It should be noted that, the first reference signal and the second reference signal are not limited to reference signals in the angular direction and the altitude direction, and may be 5 reference signals in any direction based on actual cases. In this case, the pre-coding processing may be adapted to improve a receiving level for the reference signal of user equipment in a corresponding direction. [0084] Alternatively, corresponding to the above description, in a case that the second reference signal is a wideband!long-term signal, the first reference signal may be transmitted 10 on one or several narrowbands (for example subbands) and have a relatively short transmission cycle. Specifically, the first reference signal may be distributed on one or more .narrowbands (for example subbands) and does not cover the whole bandwidth. Accordingly, .the user equipment performs a short-term/narrowband (subband) feedback for the first reference signal to acquire further information on the channel. 15 (0085) Preferably, the pre-coding unit 104 may be further configured to pre-code the first reference signal based on channel information related to other communication apparatus. Specifically, in addition to the first channel information related to current user equipment, the pre-coding unit I 04 may pre-code a first reference signal for the current user equipment further based on channel information related to other communication apparatus (for example, 20 the channel feedback information related to other user equipment obtained by the two exemplary ways described above). By considering channel information fed back by multiple user equipment in combination, it is possible to further effectively increase the receiving level for the first reference signal of the user equipment, improve the feedback accuracy, and simplify complexity of the pre-coding operation at base station end. 25 [0086] The measurement configuration information generating unit I 06 may be configured '''·" to generate measurement configuration information for the second communication apparatus, where the measurement configuration information may include a measurement indication for the pre-coded first reference signal. [0087] It should be understood that, in the above examples, when 'the base station sends the 30 second i'eference signal to the user equipment, the base· station also needs to send a measurement indication for the second reference signal to the user' egll1pment. That is, the - 15 - Sony China Ref.: CNPA 15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original base station may indicate to the user equipment through signaling for example downlink control information (DCI) or the like, and thus the user equipment may measure a corresponding reference signal and perform corresponding measurement feedback in response to the indication. In addition, the base station may utilize for example an RRC signaling to 5 carry measurement configuration information, for example, notifY antenna port numbers for sending respective reference signals to the user equipment. [0088] The controlling unit 1 08 may be configured to control data signal transmission based on second channel information, which is fed back for the pre-coded first reference signal by the second communication apparatus according to the measurement configuration 1 o information. [0089] Specifically, for example, in response to the measurement configuration information, the second communication apparatus (for example, user equipment) may perform corresponding measurement and feed back a measurement result to the first communication apparatus (for example, a base station) through PMI, CQI and RI and so on as second channel 15 information, and thus the base station may perform operations related to data signal transmission, for example, channel recovering, pre-coding, scheduling, modulation coding scheme setting and so on, according to the received second channel information. [0090] As a preferred example, the controlling unit 108 may be further_ configured to control data signal transmission further based on channel information related to other 20 communication apparatus. Specifically, the controlling unit 108 may control the operations related to data signal transmission, for example, user pair selection, resource allocation and so on in multiple user multiple input multiple output (MU-MIMO) processing, further based on the measurement result for the pre-coded first; .reference signal fed back from other communication apparatus (for example other user equipment), i.e., second channel ·. 25 information fed back by other user equipment, tc\ the base station for example. [0091 J Preferably, corresponding to the first channel information, the second channel information may be channel information in an angular direction (for example a horizontal direction) or further information on the channel (i.e., more accurate infom1ation). For example, in a case that the second channel information is channel information in the horizontal 30 direction, in subsequent operations, the controlling unit 108 may pre-code in the horizontal direction b~sed on the second channel information. The pre-coding..i11 the horizontal direction - 16- Sony China Ref.: CNPAI5002INOO Sony Ref.: please provide Unital en Ref.: OPI715-06-1 042 Original may be performed by adopting a pre-coding method which is not based on a code book (for example ZF pre-coding, MMSE pre-coding or the like), so as to further effectively increase a receiving level for the first reference signal of the user equipment, improve feedback accuracy and simplifY complexity of a pre-coding operation at base station end. Alternatively, a 5 pre-coding method based on a code book may also be adopted, and the code book may be a code book in the existing long term evolution-advanced (LTE-A) system. [0092] As can be seen from the above description, according to the embodiment of the present disclosure, by performing pre-coding in the vertical direction, it is possible to sufficiently utilize a degree of freedom in the vertical direction, thereby effectively increasing 10 the receiving level for the reference signal in the horizontal direction of the user equipment and reducing operation complexity. In addition, by performing a two-stage channel estimation and feedback (i.e., firstly obtaining preliminary information on the channel and then obtaining further information on the channel), relatively accurate information on the channel can be obtained, thereby optimizing the system performance. 15 [0093] Preferably, the pre-coding unit may select to consider channel information fed back by some rather than all of the user equipment on different radio resources, in performing the pre-coding operation. That is, if it does not need to consider channel information fed back by some of user equipment on the same radio resource, it is unnecessary to send the pre-coded first reference signal to these user equipment. Subsequently, an example in this case is 20 described by referring to Figure 2. Figure 2 shows a block diagram of another functional configuration example of a device in a wireless communication system according to an embodiment of the present disclosure. [0094] As shown in Figure 2, a device 200 according to the example may include a channel information acquiring unit 202, a determining unit 204, a pre-coding unit 206, a measurement 25 configuration information ... generating u::1it 208 and a controlling unit 210, .,Functional ·· configuration examples of the channel information acquiring unit 202, the pre-coding unit 206, the measurement configuration information generating unit 208 and the controlling unit 210 are substantially the same as functional configuration examples of corresponding units described above by referring to Figure 1, and are not repeated here. Hereinafter only a 30 flllictional configuration example of the determining unit 204 is described in detaiL . [OJJ95J_ In the example, preferably, the channel information acquiring unit 202 may be - 17 - Sony China Ref.: CNPA 15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original configured to acqmre first channel information of multiple second communication apparatuses respectively. [0096] The determining unit 204 may be configured to determine, based on the first channel information of the multiple second communication apparatuses, whether a first 5 communication apparatus is to send the pre-coded first reference signal to a corresponding second communication apparatus. In this way, based on a determination result of the determining unit 204, a base station may selectively send the pre-coded first reference signal to the user equipment. That is, according to the fed back channel information, the base station may select the user equipment to which the pre-coded first reference signal is to be sent. In 1 0 this way, resource overhead for transmitting the reference signal can be reduced to a certain degree. Further, as a preferred example, the determining unit 204 may further determine, according to a specific optimization target, to which of the multiple second communication apparatuses the first communication apparatus is to send the pre-coded first reference signal_ [0097] Preferably, the pre-coding unit 206 may be further configured to pre-code, based on 15 the determination result of the determining unit 204, the first reference signal for the first channel information of one or more of the multiple second communication apparatuses. [0098] For example, if it is determined that a charmel quality between some user equipment and the base station is poor according to the channel information fed back by the user equipment, the determining unit 204 determines that no MU-MIMO processing is performed 20 on these user equipment subsequently and no further channel information is needed, and thus the pre-coding unit 206 may perform the pre-coding operation without considering these user equipment. [0099] Specifically, as an example, the pre-coding unit 206 may calculate pre-coding matrixes of respective second communication apparatuses for the first channel information of 25 one or more of the ·multiple secuhd communication apparatuses, and pre:code the first reference signal utilizing superposition of the pre-coding matrixes. In the example, an overall pre-coding matrix is generated by utilizing the superposition of pre-coding matrixes of the selected second communication apparatuses, and a weighting processing is performed for a first reference signal to be sent on respective antennas by using the overall pre-coding matrix, . 30 so as to completely multiplex the same physical transmission resources, thereby achieving "· ... directional transmission in multiple directions. . ,, '-· .. . 18 . . - L Sony China Ref.: CNPA150021NOO Sony Ref.: please provide Unitalen Ref.: OP\715-06-1042 Original [00100] Alternatively, as another example, the pre-coding unit 206 may calculate pre-coding matrixes of respective second communication apparatuses for the first channel information of one or more of the multiple second communication apparatuses, and pre-code the first reference signal by utilizing the pre-coding matrixes respectively. Preferably, the device 200 5 may allocate different code words, time or frequency resources to the first reference signal for one or more of the multiple second communication apparatuses to perform multiplexing. In the example, the device 200 sends the first reference signal to the selected second communication apparatuses in a manner of code division, time division or frequency division. In another example, the device 200 may select different, for example orthogonal, reference 10 signal sequences for the selected second communication apparatuses to reduce interference. [00101] Subsequently, another functional configuration example of a device in a wireless communication system according to an embodiment of the present disclosure is described by referring to Figure 3. Figure 3 shows a block diagram of another functional configuration example of a device in a wireless communication system according to an embodiment of the 15 present disclosure. [00102) As shown in Figure 3, a device 300 according to the embodiment may include a channel information acquiring unit 302, a determining unit 304, a radio resource allocating unit 306, a pre-coding unit 308, a measurement configuration information generating unit 310 and a controlling unit 312. Functional configuration examples of the channel information 20 acquiring unit 302, the determining unit 304, the pre-coding unit 308, the measurement configuration information generating unit 310 and the controlling unit 312 are substantially the same as functional configuration examples of corresponding units described above by referring to Figure 2, and are not repeated here. Hereinafter only a functional configuration example of the radio resource allocating unit 306 is described in detail. 25 [00103] The -mdio resource rHocating unit 306 may be configured to allocate radio resources for transmission of a pre-coded first reference signal and/or a data signal based on the first channel information. 30 [OOHI4] Specifically, as a preferred example, according to a determination result of the determining unit 304, if the determining unit 304 determines that it does not need to send the pre-coded first reference signal to some user equipment, i.e., no further accurate channel information is needed for these user eguipment, .. the radio resource allocating unit 306 may - 19 - Sony China Ref.: CNPA15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original allocate resources for data communication to these user equipment based on the current first channel information. [00105] In the embodiment of the present disclosure, instead of allocating radio resources based on the channel information finally fed back in the conventional technology, the radio 5 resources are allocated to the user equipment based on information on the channel in a certain dimensional direction or preliminary information on the channel, thereby improving resource utilizing efficiency. [00106] As an example, the devices 100 to 300 according to the above embodiments may be located at base station end, and in this case, the device may further include a transceiving unit 1 0 configured to perform communication with the user equipment. Subsequently, a functional configuration example of the device in this case is described by referring to Figure 4. Figure 4 shows a block diagram of another functional configuration example of a device in a wireless communication system according to an embodiment of the present disclosure. [00107J As shown in Figure 4, a device 400 according to the example may include a 15 transceiving unit 402, a channel information acquiring unit 404, a pre-coding unit 406, a measurement configuration information generating unit 408 and a controlling unit 410. Functional configuration examples of the channel information acquiring unit 404, the pre-coding unit 406, the measurement configuration information generating unit 408 and the controlling unit 410 are substantially the same as functional configuration examples of 20 corresponding units described above by referring to Figure 1, and are not repeated here. Hereinafter only a functional configuration example of the transceiving unit 402 is described in detail. [00108] The transceiving unit 402 may be configured to perform signal transceiving between a base station and user equipment. Specifically, for example, the transceiving unit 402 may be 25 configurecttO'send a s~cond reference signal to the user equipment, receiv'b first channel information fed back by the user equipment, send a pre-coded first reference signal and corresponding measurement configuration information to the user equipment, and receive second channel information fed back by the user equipment. In addition, the transceiving unit 402 may be also configured to receive a third reference sigual from the user equipment for 30 channel estimation. Further, the transceiving unit 402 may be further configured to .receive channel feedback information from other user equipment. Sony China Ref.: CNPA15002INOO Sony Ref.: please provide Unital en Ref.: OP1715-06-l 042 Original [00109] Figure 5 shows a block diagram of a functional configuration example of a device in a wireless communication system according to another embodiment of the present disclosure. The device may be located at user equipment end for example, but the present disclosure is not limited thereto. The device may also be located at a small base station or other 5 infrastructure having the function of the user equipment. [00110] As shown in Figure 5, a device 500 according to the embodiment may include a measuring unit 502 and a feedback information generating unit 504. Subsequently functional configuration examples of respective units are described in detail. [00111] The measuring unit 502 may be configured to measure a pre-coded first reference 10 signal from a first communication apparatus based on measurement configuration information for a second communication apparatus from the first communication apparatus, where the measurement configuration information may include a measurement indication for the pre-coded first reference signal. As an example, the first communication apparatus may be a base station, and the second communication apparatus may be user equipment. 15 [00112] The feedback information generating unit 504 may be configured to generate, based on measurement for the pre-coded first reference signal, feedback information as second channel information on a channel between the first communication apparatus and the second communication apparatus, for the first communication apparatus to control data signal transmission. Specifically, after channel estimation according to the pre-coded first reference 20 signal, the feedback information generating unit 504 may perform quantization according to a corresponding code book to generate the second channel information. The second channel information may be for example channel information in the angular direction or further information on the channel as described above. Specifically, as an example, corresponding to the description for the device at the base station end, the feedback information generating unit 25 5Q~,may estimate -·- > W hK ] w E CMXx l ' ' , where h,k indicates a pre-coding vector in a horizontal direction of the k-th user, then a pre-coding matrix of the k-th nser (i.e., I 0 the third pre-coding matrix described above) is constructed as: [00164) As can be seen, with the pre-coding scheme of the present disclosure, the extra degree of freedom in the vertical direction can be utilized sufficiently. Therefore, as compared with the existing scheme, interference between users can be effectively reduced; and as 15 compared with the full space pre-coding scheme, complexity of the pre-coding operation can be reduced significantly. In addition, in combination with the two-stage channel estimation and feedback scheme described above, the pre-coding scheme described above may be applied to scenes for example TDD, FDD and so on and is also adapted to a multi-cell scene. A simulation result for the multi-cell scene is described later by referring to Figure 19 to .40 Figure ::?1. [00165] It should be noted that, although the pre-coding scheme of the present disclosure is described by performing pre-coding in the vertical direction and the horizontal direction respectively, the present disclosure is not limited thereto, and the two-step pre-coding scheme may be applied to other cases according to the principle of the present disclosure, for example, 25 two- or more- step pre-coding operation in directions in addition to the .vertical direction and the horizontal direpti,on, pr performing the pre-coding operation by ,<;:ons~ructing a - 32- Sony China Ref.: CNPA15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original corresponding pre-coding matrix according to channel feedback information obtained at two times (for example, preliminary channel information and further channel information), without considering specific directions. [00166] Subsequently, in order to facilitate understanding of the above process, an example 5 of an interaction process regarding channel estimation and feedback and subsequent data signal pre-coding between a first communication apparatus and a second communication apparatus is described by referring to a flowchart shown in Figure 13. Figure .13 shows a schematic diagram of an example of an interaction process in a wireless communication system according to an embodiment of the present disclosure. Here, description is made by 10 taking an interaction between a base station and user equipment as an example, but the present disclosure is not limited thereto. [00167] As shown in Figure 13, firstly, in step S1301, the base station may obtain first channel information in any exemplary way described by referring to Figure 8 or Figure 9. Subsequently, in step S 1302, the base station may select user equipment to which a pre-coded 15 first reference signal is to be sent according to the frrst channel information, calculate a first pre-coding matrix based on the selection result in step Sl303, and pre-code the first reference signal utilizing the first pre-coding matrix in step S1304. Subsequently, in step Sl305, the base station sends the pre-coded first reference signal and corresponding measurement configuration information to the user equipment. In step S 1306, the user equipment performs, 20 in response to the measurement configuration information,. channel estimation according to the pre-coded first reference signal, and in step Sl307, the user equipment feeds back second channel information obtained by estimation to the base station. Subsequently, in step S 1308, the base station may calculate, by utilizing the above methods, a second pre-coding matrix according to the second channel information and the first pre-coding matrix. In step Sl309, 25 the base station calculates a third pre-coding matrix according to a Kronecker product of the . ;, \h.,. ., l first pre-coding matrix and the second pre-coding matrix, and pre-codes a data signal utilizing the third pre-coding matrix in step S 1310. [00168] It should be understood that, the above interaction process is only exemplary, and those skilled in the art may modify the above interaction process according to the principle of 30 the present disclosure. For example, the selection operation in step S1302 may be omitted, and the pre-coded first reference signal may be directly sent to all user equipment, but this ,. -· ·-': . ".,., -·-. ·'· - 33- might result iu a waste of resources. Sony China Ref.: CNPA15002INOO Sony Ref.: please provide UnitalenRef.: OP1715-06-1042 Original [00169] Subsequently, an example of a structure of a wireless communication system according to an embodiment of the present disclosure is described by referring to Figure 14. Figure 14 shows a block diagram of an example of a structure of a wireless communication 5 system according to an embodiment of the present disclosure. [00170] As shown in Figure 14, a wireless communication system 1400 according to the embodiment may include a first communication apparatus 1402 and a second communication apparatus 1404. [00171] The first communication apparatus 1402 may be configured to: acquire first channel 1 0 information on a channel between the first communication apparatus and the second communication apparatus; pre-code a first reference signal based on the first channel information; generate measurement configuration iuformation for the second communication apparatus, where the measurement configuration information includes a measurement iudication for the pre-coded first reference signal; and control data signal transmission based 15 on second channel iuformation, which is fed back for the pre-coded first reference signal by the second communication apparatus according to the measurement configuration information. The first communication apparatus 1402 may be a base station for example, which may include the device described by referring to Figure 1 to Figure 4. [00172] The second communication apparatus 1404 may be configured to: measure the 20 pre-coded first reference signal based on the measurement configuration iuformation; and generate feedback information as the second channel information based on measurement for the pre-coded first reference signal. The second communication apparatus 1404 may be user equipment for example, which may include the device described by referring to Figure 5 to Figure 7 for example. 25 [00173] It should be understood that, although ~nctional configuration examples of the devices in a wireless communication system and the wireless communication system and examples of the interaction process between correspondiug communication apparatuses according to the embodiments of the present disclosure are described above, they are only exempl~y and not intended to be limitations. Those skilled in the art may modify the above 30 embodiments according to the principles of the present disClosure, for example, add, delete and! or combine functional modules in various embodiments, and all of such modifications fall - 34- within the scope of the present disclosure. Sony China Ref.: CNPA150021NOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1 042 Original [00174] Corresponding to the above device embodiments, methods in a wireless communication system are further provided according to an embodiment of the present disclosure. Hereinafter process examples of methods in a wireless communication system 5 according to an embodiment of the present disclosure are described in detail by referring to Figure 15 to Figure 17 respectively. [00175] Figure 15 shows a flowchart of a process example of a method in a wireless communication system according to an embodiment of the present disclosure. The method according to the embodiment corresponds to the device at the base station end described 10 above. [00176] As shown in Figure 15, the method according to the embodiment may include a channel information acquiring step Sl502, a pre-coding step S1504, a measurement configuration information generating step Sl506 and a controlling step S1508. Subsequently processing in various steps is described respectively. 15 [001771 In the channel information acquiring step S1502, first channel information on a channel between a first communication apparatus and a second communication apparatus may be acquired. The first channel information may be acquired in any way described by referring to Figure 8 or Figure 9, and the first channel information may be information in an altitude or angular direction or preliminary information on the channeL 20 [00178] Subsequently, in the pre-coding step Sl504, a first reference signal may be pre-coded based on the first channel information. The pre-coding processing may be performed utilizing a pre-coding algoritlrm which is not based on a code book, for example a ZF pre-coding algorithm, an MMSE pre-coding algorithm and the like, to eliminate interference between different user equipment for example. 25 [00179] Subsequently, in the measuring configuration information generating step Sl506, measurement configuration information for the second communication apparatus may be generated. The measurement configuration information may include a measurement indication for the pre-coded first reference signal, to indicate to the second communication apparatus (for example, the user equipment) which reference signal isto be measured. 30 [OOl~Ol . ~ubsequently, in the controlling step S 1508, data signal transmission may be -35. Sony China Ref.: CNPA15002INOO Sony Ref.: please provide Unital en Ref.: OP\715-06-1 042 Original controlled based on second channel information, which is fed back for the pre-coded first reference signal by the second connnunication apparatus according to the measurement configuration information. For example, operations such as pre-coding the data signal, scheduling and so on may be performed based on the second channel information. 5 [00181] Figure 16 shows a flowchart of a process example of a method in a wireless connnunication system according to another embodiment of the present disclosure. The method according to the embodiment corresponds to the device at the user equipment end described above. [00182] As shown in Figure 16, the method according to the embodiment may include a 10 measuring step S 1602 and a feedback information generating step S 1604. (00183] In the measuring step S 1602, a pre-coded first reference signal from a first communication apparatus may be measured based on measurement configuration information for second connnunication apparatus from the first connnunication apparatus, where the · measurement configuration information may include a measurement indication for the 15 pre-coded first reference signaL As an example, the first reference signal may be a reference signal in an angular or altitude direction, or a reference signal in any direction. [00184] Subsequently, in the feedback information generating step Sl604, based on measurement for the pre-coded first reference signal, feedback information may be generated as second channel information on a channel between the first connnunication apparatus and 20 the second communication apparatus, for the first communication apparatus to control data signal transmission. The second channel information may be channel information in an angular direction or an altitude direction for example, or further information on the channel. [00185] Preferably, in the measuring step S1602, a second reference signal from the first connnunication apparatus (for example, a reference signal in the altitude direction or angular \" 25 direction, or a reference signal in any direction) may be measured, and in the feedback information generating step S 1604, feedback information for the second reference signal is generated as first channel information, for the first connnunication apparatus to pre-code the fnst reference signal, allocate radio resources to the user equipment and so on. {00186] Figure 17 shows a flowchart of a process ·example of a method m a wireless 30 .. communication system according to another embodiment of the present disclosure. The -36- Sony China Ref.: CNPA15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original method according to the embodiment corresponds to the device for pre-coding a data signal at the base station end described above. [00187] As shown in Figure 17, the method according to the embodiment may include a first generating step S 1702, a second generating step S 1704 and a pre-coding step S 1706. 5 [00188] In the first generating step S 1702, a first pre-coding matrix may be generated according to first channel information on a channel between a fust communication apparatus and a second communication apparatus. The first channel information may be the first channel information obtained by the above methods, or channel information obtained by other methods. 10 [00189] Subsequently, in the second generating step Sl704, a second pre-coding matrix may be generated according to the first pre-coding matrix and second channel information on the channel. The second channel information may be the second channel information obtained by the above methods, or channel information obtained by other methods. [001901 Subsequently, in the pre-coding step S 1706, a data signal may be pre-coded 15 according to the fust pre-coding matrix and the second pre-coding matrix. Specifically, a third pre-coding matrix may be generated according to a Kronecker product of the first pre-coding matrix and the second pre-coding matrix, and the data signal is pre-coded utilizing the third pre-coding matrix. [00191] It should be noted that, process examples of the methods in the wireless 20 communication system according to the embodiments of the present disclosure are described above, but these are only examples and not intended to be limitations. Those skilled in the art may modifY the above embodiments according to the principles of the present disclosure, for example add, delete and/or combine steps in various embodiments or the like, and all of such modifications fall within the scope of the present disclosure. 25 [00192] In addition, it should be noted that, the method embodiments here correspond to the device embodiments described above, and hence contents which are not described in detail in the method embodiments may be referred to the description at corresponding positions of the device embodiments, and are not repeated here. [00193] In addition, an electronic apparatus ls further provided according to an embodiment .'' 3.0 of the present disclosure. The electronic apparatus may include one or more processors -37. Sony China Ref.: CNPA150021NOO Sony Ref.: please provide Unital en Ref.: OP1715-06-l 042 Original configured to perform the methods in a wireless communication system according to the embodiments of the present disclosure. [00194] It should be understood that machine-executable instructions in a storage medium and a program product according to the embodiments of the present disclosure may be also 5 configured to execute the methods corresponding to the apparatus embodiments described above, thus contents which are not described in detail may be referred to foregoing description at corresponding positions, which are not described repeatedly here anymore. [00195] Accordingly, a storage medium on which the above program product storing machine executable instructions is carried is also included in the disclosure. The storage I 0 medium includes but not limited to a floppy disk, ap. optical disk, a magneto-optical disk, a storage card, a memory rod and the like. [00196] Furthermore, it shall be noted that the foregoing series of processes and apparatuses can also be embodied in software and/or firmware. In the case of being embodied in software and/or firmware, a program constituting the software is installed from a storage medium or a 15 network to a computer with a dedicated hardware structure, e.g., a general purpose personal computer 1800 illustrated in Figure 18, which can perform various functions when various programs are installed thereon. (00197] In Figure 18, a Central Processing Unit (CPU) 1801 performs various processes according to a program stored in a Read Only Memory (ROM) 1802 or loaded from a storage 20 portion 1808 into a Random Access Memory (RAM) 1803 in which data required when the CPU 1801 performs the various processes is also stored as needed. [00198] The CPU 1801, the ROM 1802 and the RAM 1803 are connected to each other via a bus 1804 to which an input/output interface 1805 is also connected. [00199] The following co,nponents are cmmected to the input/outputinterface 18?,5: an input 25 portion 1806 including a keyboard, a mouse, etc.; an output portion 1807 including a display, e.g., a Cathode Ray Tube (CRT), a Liquid Crystal Display (LCD), etc., a speaker, etc.; a storage portion 1808 including a hard disk, etc.; and a communication portion 1809 including a network interface card, e.g., an LAN card, a modern, etc. The communication portion 1809 performs a communication process over a network, e.g., the Internet. 30 [00200] A drive 1810 is also connected to the input/output interface 1805 as needed. A Sony China Ref.: CNPA15002INOO Sony Ref.: please provide Unitalen Ref.: OP\715-06-1042 Original removable medium 1811, e.g., a magnetic disk, an optical disk, an magneto optical disk, a semiconductor memory, etc., can be installed on the drive 1810 as needed so that a computer program fetched therefrom can be installed into the storage portion 1808 as needed. [0020 1] In the case that the foregoing series of processes are performed in software, a 5 program constituting the software is installed from a network, e.g., the Internet, etc., or a storage medium, e.g., the removable medium 1811, etc. [00202] Those skilled in the art shall appreciate that such a storage medium will not be limited to the removable medium 1811 illustrated in Figure 18 in which the program is stored and which is distributed separately from the apparatus to provide a user with the program. I 0 Examples of the removable medium 1811 include a magnetic disk (including a Floppy Disk (a registered trademark)), an optical disk (including Compact Disk-Read Only memory (CD-ROM) and a Digital Versatile Disk (DVD)), a magneto optical disk (including a Mini Disk (MD) (a registered trademark)) and a semiconductor memory. Alternatively the storage medium can be the ROM 1802, a hard disk included in the storage portion 1808, etc., in 15 which the program is stored and which is distributed together with the apparatus including the same to the user. (00203] Subsequently, simulation of the system performance in a case that the technology of the present disclosure is applied is described by referring to Fignre 19 to Figure 21, so as to illustrate improvement in the system performance achieved by the technology of the present 20 disclosure as compared with the conventional technology. [00204) A multiple-cell multiple-user scene is considered. Let L=7 indicate the number of cells and K =8 indicate the number of users served in the same time-frequency resource. A base station is located at a center of each cell, and user equipment are distributed randomly. Figure 19 shows a schematic diagram of an example of distribution of communication 25 apparatuses in a simulation. For spread of an arrival angle, it is assumed that the spread of an angle in a horizontal. direction is 180 degrees, the spread of an angle in a vertical direction is only 5 degrees, and the arrival angle follows uniform distribution. [00205] It is assumed that the base station has acquired the charmel status information using the two-stage channel estimation and feedback scheme according to the embodiment of the H E~yxMx 30 present disclosure described above.· It is assumed that kls indicates a - 39- Sony China Ref.: CNPA 15002INOO Sony Ref.: please provide Unitalen Ref.: OP1715-06-1042 Original channel matrix from a base station in an s-th cell to k-th user equipment in an l-th cell. The following narrowband channel model is adopted in the simulation: p Hlds E CMyxMr = L H~ p~l HP [00206] Where P=lO indicates the number of multiple paths. A matrix kls indicates a HP 5 channel matrix of the p-th sub-path. An element in row m and column n of the matrix kls lS: hm.n.p _ p { ·2 D(( 1) ()P RP ( 1) · RP )' kls - Pkis exp -1 JT:- m - cos Ids cos 1-'kls + n - SID 1-'kis f A, [00207] Where efds and fJ~ indicate arrival angles in a horizontal direction and a vertical . p direction respectively. Pkis indicates a large-scale fading coefficient and is calculated from 10 the following equation: [00208] Where dkls indicates a distance from a base station in an s-th cell to k-th user equipment in an l-th cell, a indicates a path loss coefficient, p 2kls indicates a shadow fading coefficient and follows a logarithm normal distribution with a vanance In the 15 simulation, it is assumed that a=3.5, az=SdB. [00209] An estimated channel obtained at the base station end of the l-th cell is: [00210] The base station in the l-th cell obtains a pre-coding matrix utilizing the estimated channel in the above equation and uses the same to transmit downlink data. 20 (00211] Simulations are performed by adopting the existing scheme and the· twc