DESC:TECHNICAL FIELD
The present disclosure relates generally to radio communication systems, and more particularly relates to diplex cognitive radio communication systems.
BACKGROUND
Spectral resource demand has greatly increased in the last two decades due to emerging wireless services and products. Cognitive radio emerges as a way to improve the overall spectrum usage by exploiting spectrum opportunities in both licensed and unlicensed bands. The cognitive cycle begins with sensing a radio frequency (RF) medium: radios are able to exploit information about the wireless environment to be aware of local and temporal spectrum usage. Opportunistic cognitive users may dynamically select the best available channels and adapt their transmission parameters between other cognitive users. Recently, the concept of cognitive radio has been used in tactical applications, in the perspective of jammer avoidance. Further, cognitive radio with sensing capability prevents manual interventions and provides seamless communication between the combat vehicles in the battlefield.
In conventional cognitive radio systems, the spectrum sensing is performed at the beginning of each time slot, before data transmission, and during data transmission, sensed information is also transmitted. Critical concerns of such cognitive radio operation are that, the embedding of the sensing information drastically reduces data transmission time, which may reduce the throughput, thereby limiting overall data capacity.
To overcome this limitation, dual channel radio frequency (RF) architecture exists. In the dual channel RF architectures, a separate RF channel is used for sensing and control bit transmission, and another RF channel for data bit transmission. In this approach, cognitive radio systems use an out of-band control channel to perform resource negotiation and share results of spectrum sensing. The out-of-band control channel is physically separated from the in-band channel where data transmission occurs. Further, the dual channel RF architecture supports and simultaneously senses the spectrum and transmits data through a second RF channel, i.e., the other RF channel. Even though the dual channel RF architectures address the issues faced by conventional cognitive radio systems, the dual channel RF architecture is costly and requires dual RF bandwidth.
To address the issues with respect to the cost and requirement of dual RF bandwidth, there exist techniques to handle signaling exchange and data transmissions over the same channel (i.e., in-band signaling). For instance, in IEEE 802.22, a logical in-band control channel is exploited, where sensing results are piggybacked over data transmissions. However certain limitations are associated therewith, as a considerable amount of throughput is reduced in terms of sharing the control bits. In addition, a data channel is used for negotiation for spectrum changeover, and in an instance when the data channel undergoes any jamming issues, a recovery channel is not available.
There are other approaches, which work based on local decisions, called autonomous mechanisms. When neither decision-making coexistence infrastructures nor internetwork coordination channels are available, each coexisting network has to utilize autonomous mechanisms to achieve best effort interference mitigation. Each coexisting network performs resource allocation and manages internetwork interference only based on local observation. For example, the dynamic frequency/channel selection technique enables each network to select or switch to the channel with the least amount of interference based on the local evaluation of channel quality. A listen-before-talk policy prescribes a device to access spectrum based on the outcome of local spectrum sensing. Autonomous mechanisms are low in complexity and can adapt to dynamic environments. Autonomous mechanisms by themselves may not sufficiently mitigate internetwork interference due to their best-effort nature.
The approaches illustrated herein above are well suited for point-to-point cognitive radios. As the cognitive users form a network, the common control channel negotiation has to be obtained from all cognitive radios’ nodes in the network. When a cognitive radio receiver is not in the transmitting range of a cognitive radio sender, data is forwarded through several hops forming a Multi-Hop Cognitive Radio Network (MHCRN). In such instance, unlike in a normal multi-hop network in which all users operate in the same channel, users in a MHCRN use different frequencies depending on spectrum availability. As a result, two CR users are connected depending on whether they have a common frequency band for operation.
A MHCRN is, in many ways, similar to a multi-channel network. In both networks, each user has a set of channels available for communication. In this approach, when two users want to communicate, the two users negotiate via a common control channel (CCC) to select a communication channel. Two major differences in these two network environments are that the number of channels available at each node is fixed in a multichannel network, whereas it is a variable in MHCRN. Also, it is possible that a user has no available channel at all due to the jammed scenarios or channel occupancy state.
In a case where cognitive radio users in the network can have more than one channel, initial handshake signals called control signals are generated to negotiate the choice of a common channel. In such an instance, such negotiations require communication over a common signaling channel, i.e., the CCC problem. In the case of the operation of the CCC without limiting the scope, for instance, Node A has channels 1, 3, and 4 available and Node B has 1, 2, and 4 available. In such an instance, the available channels form the channel set of the respective pair of nodes. In instances when the Node A is unaware of Node B’s channel set and vice versa, channels 1 and 4 are common among the two nodes, i.e., A and B. Thus, in case node A wants to transmit to node B, A and B should negotiate channel sets, and exchange control messages such as ‘Request to Send’ (RTS) and ‘Clear to Send’ (CTS) messages to reserve a channel for communication.
The control messages mentioned above, in turn, have to be negotiated via a channel. Generally, a separate dedicated channel for control signals would seem a simple solution. However, as also stated above, having a dedicated CCC includes limitations associated with it. Specifically, a dedicated channel for control signals is wasteful of channel resources. Secondly, a control channel would get saturated as the number of users increases similar to a multi-hop network. Thirdly, an adversary can cripple the dedicated control channel by intentionally flooding the control channel. This is the Denial of Service (DoS) attack.
Further, the probability of having CCC among all nodes in the cognitive radio network is very small. To address the limitations of the availability of CCC, there exists a cluster head concept, in which a group of users that are close together form a sub-ad hoc network and select a channel for communicating control information. In an instance when the channel is jammed or becomes unavailable, a different channel which is available to everyone in the subgroup is chosen. It is assumed that one of the members of the group has the capability to connect to the neighboring groups. The existing solution is an indirect solution to the problem of the availability of the CCC and does not completely eliminate the dependency on the CCC. There is still a possibility that a user can pose a DoS attack.
However, in all the existing approaches, as mentioned above, implementing control channel communication either compromises the throughput or requires additional RF channel.
For the coexistence of two parallel transmissions, there are three concepts including an overlay, an underlay, and an interweave. In the overlay, both the parallel transmissions have full and non-causal knowledge about each other’s waveform and use advanced coding and modulation strategies to transmit simultaneously while mitigating interference among each other. Interweave is based on an idea of opportunistic communication. For instance, one user may act as a primary user (PU) having priority to use the channel at any time, and hence another user, i.e., another secondary user may scan for the white spaces that may not be used by the PU transmission and may be scaled in space, time or frequency. In case of interweave approach, there are no privileges for coexistence or concurrent communication. Further, the underlying approach requires partial knowledge about co-users, so that the secondary user can co-exist in the same channel as the primary user with minimal interference.
The concept of overlay may be used in the present disclosure to make the data and control information co-exist in the same channel with a single RF. However, the existing approaches for single RF architecture compromise the data throughput for transmitting control and data information which are not throughput efficient solutions. Further, there exist certain art and other techniques that achieve control channel communication of cognitive radios.
One of the existing arts suggests that the channel’s capacity, subject to a transmit power constraint, can remain unchanged even when an interference signal S is present, as long as S is known non-causally at the transmitter. The approach suggested by the existing art suggests that the transmitter must possess knowledge not only of the current and past history of S but also of its future values. This setup precisely mirrors a multiuser downlink scenario, where the interfering signal corresponds to the transmit signal intended for other users. The transmitter has non-causal knowledge of the interference because the source information bits are typically stored in a buffer, and future values of the interference can be pre-constructed from the buffered bits. The existing approach suggests a transmitter endeavoring to encode information on a piece of paper that is partially corrupted by dirt. This dirt is visible to the transmitter but unknown to the receiver. Precoding methods designed for the dirty paper channel are sometimes referred to as "dirty-paper precoding."
Another existing art suggests generalizations of Tomlinson-Harashima precoding aimed at mitigating some of the losses. At high Signal-to-Noise Ratios (SNR), shaping loss dominates the precoding loss, reaching approximately 1.53dB. To recover this shaping loss, a trellis shaping technique is devised, considering the entire non-causal interfering sequence's knowledge rather than just the instantaneous interference. Demonstrated at rates of 2 and 3 bits per transmission, trellis shaping proves capable of recovering nearly all of the 1.53dB shaping loss. At low SNR, the precoding loss is primarily attributed to power and modulo losses, potentially reaching 3- 4dB. To counter these losses, a technique is developed that integrates partial interference pre-subtraction within convolutional decoding. At rates of 0.5 and 0.25 bits per transmission, this approach can recover 1-1.5dB of the power loss. For channels with intermediate SNR, a combination of both schemes is shown to effectively recover both power and shaping losses.
A yet another existing art outlines a dirty paper (DP) coding scheme incorporating trellis shaping designed for an overlay cognitive radio channel. In this channel configuration, a cognitive user and a primary user transmit simultaneously within the same spectrum. The interference from the primary user is assumed to be non-causally known at the cognitive transmitter.
An existing art suggests that cognitive networks play a pivotal role in facilitating efficient radio spectrum sharing. A multi-hop cognitive network, specifically, operates as a cooperative network where cognitive users collaborate with their neighboring nodes to relay data to the intended destination. The coordination among cognitive users is facilitated through control signals that traverse a common control channel (CCC). However, the utilization of a common control channel introduces challenges such as channel saturation, leading to degradation in the overall performance of the network. Consequently, the exchange of control information emerges as a significant hurdle in the context of cognitive radio networks. This paper introduces an innovative Medium Access Control (MAC) protocol designed for multi-hop cognitive radio networks, aiming to eliminate the need for a common control channel.
Another existing art suggests approaches that describe cognitive radio receiver architecture, multiple specialized receiver algorithms operate concurrently. This includes parallel execution of algorithms such as maximal ratio combiner and beam forming. The receiver system employs various hypothetical fields of classification searches, each corresponding to different channel conditions. Subsequently, the system computes solutions based on these searches and selects the optimal result. This capability allows the receiver to decode data effectively by choosing the most suitable outcome from one of the parallel receivers.
One of the existing arts suggests methods for adjusting the frequency band used in a cognitive wireless system and wireless communication device. The method involves several steps in a cognitive radio system: 1. Determination Step: This step involves deciding on a frequency band that will serve as both a control and data channel. 2. Detection Step: Each of the transmitting and receiving nodes engages in detecting usable frequency bands within a specified frequency range. These bands are considered suitable for the control channel. Moreover, a distinctive characteristic of this frequency band coordination method is that the frequency band designated as the control channel is positioned lower than the frequency band allocated for the data channel.
To address these problems as mentioned above, a diplex overlay cognitive radio system is disclosed in the present disclosure. The present disclosure may include a Diplex Overlay Cognitive Radio (CR) architecture with Dirty paper (DP) model based encoder and decoder.
SUMMARY OF THE INVENTION
This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the invention. This summary is neither intended to identify key or essential inventive concepts of the invention nor is it intended for determining the scope of the invention.
In one embodiment, a diplex overlay cognitive radio system is disclosed. The diplex overlay cognitive radio system includes a transmitter baseband module comprising a cognitive encoder configured to receive a plurality of data bits and a plurality of control bits from a plurality of units of the transmitter baseband module. The cognitive encoder is configured to encode and combine each of the plurality of data bits and the plurality of control bits and transmit a combinedly encoded each of the plurality of data bits and the plurality of control bits via a Radio Frequency (RF) transmitter channel.
In another embodiment, a diplex overlay cognitive radio system is disclosed. The diplex overlay cognitive radio system includes a receiver baseband module, comprising a cognitive decoder and a spectrum sensing module. The cognitive decoder is configured to receive a combinedly encoded each of a plurality of data bits and a plurality of control bits via an RF receiver channel. Further, the cognitive decoder is configured to decode each of the combinedly encoded each of the plurality of data bits and the plurality of control bits such that the decoded each of the plurality of data bits and the plurality of control bits achieves channel capacity in the RF receiver channel in the diplex overlay cognitive radio system.
To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Figure 1 illustrates diplex overlay cognitive radio architecture, according to an exemplary implementation of the present disclosure;
Figure 2 illustrates a cognitive encoder, according to an exemplary implementation of the present disclosure;
Figure 3 illustrates coding gain blocks, according to an exemplary implementation of the present disclosure; and
Figure 4 illustrates a cognitive decoder, according to an exemplary implementation of the present disclosure.
Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
DETAILED DESCRIPTION OF THE INVENTION
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled in the art to which invention belongs. The system and examples provided herein are illustrative only and not intended to be limiting.
For example, the term “some” as used herein may be understood as “none” or “one” or “more than one” or “all.” Therefore, the terms “none,” “one,” “more than one,” “more than one, but not all” or “all” would fall under the definition of “some.” It should be appreciated by a person skilled in the art that the terminology and structure employed herein is for describing, teaching, and illuminating some embodiments and their specific features and elements and therefore, should not be construed to limit, restrict, or reduce the spirit and scope of the present disclosure in any way.
For example, any terms used herein such as, “includes,” “comprises,” “has,” “consists,” and similar grammatical variants do not specify an exact limitation or restriction, and certainly do not exclude the possible addition of one or more features or elements, unless otherwise stated. Further, such terms must not be taken to exclude the possible removal of one or more of the listed features and elements, unless otherwise stated, for example, by using the limiting language including, but not limited to, “must comprise” or “needs to include.”
Whether or not a certain feature or element was limited to being used only once, it may still be referred to as “one or more features” or “one or more elements” or “at least one feature” or “at least one element.” Furthermore, the use of the terms “one or more” or “at least one” feature or element do not preclude there being none of that feature or element, unless otherwise specified by limiting language including, but not limited to, “there needs to be one or more...” or “one or more elements is required.”
Unless otherwise defined, all terms and especially any technical and/or scientific terms, used herein may be taken to have the same meaning as commonly understood by a person ordinarily skilled in the art.
Reference is made herein to some “embodiments.” It should be understood that an embodiment is an example of a possible implementation of any features and/or elements of the present disclosure. Some embodiments have been described for the purpose of explaining one or more of the potential ways in which the specific features and/or elements of the proposed disclosure fulfil the requirements of uniqueness, utility, and non-obviousness.
Use of the phrases and/or terms including, but not limited to, “a first embodiment,” “a further embodiment,” “an alternate embodiment,” “one embodiment,” “an embodiment,” “multiple embodiments,” “some embodiments,” “other embodiments,” “further embodiment”, “furthermore embodiment”, “additional embodiment” or other variants thereof do not necessarily refer to the same embodiments. Unless otherwise specified, one or more particular features and/or elements described in connection with one or more embodiments may be found in one embodiment, or may be found in more than one embodiment, or may be found in all embodiments, or may be found in no embodiments. Although one or more features and/or elements may be described herein in the context of only a single embodiment, or in the context of more than one embodiment, or in the context of all embodiments, the features and/or elements may instead be provided separately or in any appropriate combination or not at all. Conversely, any features and/or elements described in the context of separate embodiments may alternatively be realized as existing together in the context of a single embodiment.
Any particular and all details set forth herein are used in the context of some embodiments and therefore should not necessarily be taken as limiting factors to the proposed disclosure.
The present disclosure describes a diplex overlap cognitive radio system.
In the following description, for the purpose of explanation, specific details are set forth in order to provide an understanding of the present disclosure. It will be apparent, however, to one skilled in the art that the present disclosure may be practiced without these details. One skilled in the art will recognize that embodiments of the present disclosure, some of which are described below, may be incorporated into a number of systems.
However, the systems and methods are not limited to the specific embodiments described herein. Further, structures and devices shown in the figures are illustrative of exemplary embodiments of the present disclosure and are meant to avoid obscuring of the present disclosure.
It should be noted that the description merely illustrates the principles of the present invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present invention. Furthermore, all examples recited herein are principally intended expressly to be only for explanatory purposes to help the reader in understanding the principles of the invention and the concepts contributed by the inventor to furthering the art and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass equivalents thereof.
As stated above, in conventional cognitive radio systems, spectrum sensing is performed at the beginning of each time slot, before data transmission, and during data transmission, the sensed information is also transmitted. Critical concerns of such cognitive radio operation are that, the embedding of the sensing information drastically reduces data transmission time, which may reduce the throughput, thereby limiting overall data capacity.
To address the limitations in the existing art as illustrated above, the present disclosure may be directed towards a diplex cognitive radio architecture design with a cognitive encoder to transmit spectrum sensing information control message ‘C’ and data message ‘D’ simultaneously through a single channel having a channel capacity same as transmitting either D or C individually without interference effect due to coexistence property using Dirty paper Coding approach. Cognitive Radio (CR) is the enabling technology for supporting dynamic spectrum access which helps to use the idle/un-used frequency band or un-jammed/error-free band to improve throughput. CRs use spectrum sensing information to switch to the best frequencies for transmitting their data messages and thus achieving performance improvement. In a cognitive radio network, cognitive radios use control channel for sharing the spectrum sensing information among the peer CRs.
Generally, conventional CRs use an out of-band control channel (the radio frequency (RF) channel which is not used for transmitting their data) to perform resource negotiation and share results of spectrum sensing. This channel is physically separated from the in-band channel where data transmission occurs. Conventional methods of transmitting Control channels are implemented using the dedicated common control channel (CCC) method or split phase method. In a dedicated CCC method, two radios with two different RF frequency bands are used to manage simultaneous transmission of signaling(C)/ (sensing information) and data transmissions (D). Eventually, CCC requires separate /dual RF channel architecture for transmitting data of CRs and control information simultaneously. With the split phase method, dual RF is not required. However, the same frequency band is time shared (TDD method) for transmitting control and data bits of CR, which results in reducing the throughput of CR.
The radio architecture of the present disclosure may transmit/receive control and data bits of cognitive radios simultaneously with a single RF architecture, with same RF frequency band, and also without time sharing (TDD) of the frequency band. The CR architecture of the present disclosure includes the cognitive encoder to combine control and data bits in such a way that, data throughput of CR is same as that of transmitting single data bits of CR. The CR architecture/system of the present disclosure may also have a cognitive decoder i.e., a two-path decoder. In an example, one of the two-path decoder may include a control bit decoder and another of the two-path decoder may include a data bit decoder, by which control information and data information may be decoded.
Channel model of the CR system of the present disclosure may be, Y= D+C+N, where Y may be the received signal, D may be the data message of the CR, C may be the control/sensing message of the CR and N-may be channel noise. The achieved data channel capacity may be 1/2 log (1+PD/PN) at the data receiver path and achieved control channel capacity may be 1/2 log (1+PC/PN) at the control receiver path.
The above capacity may be valid under the Costa theorem, which indicates that if the state D and C are respectively known at the transmitter, then the respective decoders of D or C may decode its data, without the influence of the other and can achieve the same Shannon channel capacity. In this regard, in respect of the CR architecture of the present disclosure having a cognitive encoder and a cognitive decoder, channel capacity may either not be reduced by transmitting the control bit information or there may be no need of additional RF channel for managing simultaneous transmission of control and data bits. Further, the constructional detail and the operational detail of the CR architecture are discussed in the subsequent paragraphs.
Figure 1 illustrates diplex overlay cognitive radio architecture, according to an exemplary implementation of the present disclosure. The diplex overlay cognitive radio architecture 100, as illustrated in Figure 1, includes a diplex overlay cognitive radio system S1. The cognitive radio system S1 may include a transmitter base band module S14, a radio frequency (RF) transmitter channel S5, an RF receiver channel S6, and a receiver baseband module S15. The diplex overlay cognitive radio system S1 is hereinafter interchangeably referred to as the system S1.
The radio diplex Cognitive radio hardware S1 includes a single channel RF channel for transmitting and receiving data and sensing information in parallel. The RF transmitter channel S5 may be for transmission of a joint/combined signal including data and sensing information. The RF receiver channel S6 may receive the joint/combined signal from the RF transmitter channel S5. The transmitter baseband module S14 of the diplex cognitive radio may encode and transmit the joint/combined signal, while the receiver baseband module S15 may, upon receiving an encoded joint/combined signal, decode the encoded joint/combined signal. The baseband module(s), i.e., the transmitter baseband module S14 and the receiver baseband module S15 may be developed using Field Programmable Gate Array with digital signal processing (DSPs) and memory units.
The transmitter baseband module S14 and the receiver baseband module S15 may be connected through a plurality of peripherals, for example, Universal Transceiver Access Gateway (JTAG), Universal Asynchronous Receiver-Transmitter (UART), and Universal Serial Bus (USB) in the present disclosure.
The system S1 may include one transmitter path constituted by transmitter baseband module S14 and RF transmitter channel S5. The transmitter baseband module S14 may include a cognitive encoder S4 and a plurality of units S2 and S3. The cognitive encoder S4 may be designed to be based on a Dirty Paper (DP) model. In other words, the transmitter baseband module S14 may have the cognitive encoder S4 based on the DP model and may designed to combine the plurality of control bits and the plurality of data bits. Further, the transmitter baseband module S14 may transmit both signals jointly through a single channel. Accordingly, channel capacity may not be reduced and there may be no need for an additional RF channel for managing simultaneous transmission of control and data bits, as has been explained in the foregoing paragraphs.
In an example, the cognitive encoder S4 may be configured to receive a plurality of data bits and a plurality of control bits from a plurality of units S2 and S3 of the transmitter baseband module S14. Each of the plurality of units may include a digital signal processing (DSP) unit S3 and Field-Programmable Gate Array (FPGA) unit/FPGA S2. The DSP unit S3 may be configured to generate the plurality of control bits by converting spectrum sensing information received from a RF channel into the plurality of control bits. The FPGA S2 may be configured to generate the plurality of data bits. The plurality of control bits generated from DSP units S3 may be combined with the plurality of data bits at the FPGA unit S2, using a 3-layer Trellis coder, a jointly typical encoder S22, a Partial Interference Pre-subtraction module, and modulo ? operator S24, as will be explained later.
In other words, the diplex overlay cognitive radio system S1 may have one transmitter path constituted by the RF transmitter channel S5 and the transmitter baseband module S14. The transmitter baseband module S14 may be designed with the cognitive encoder S4 and processors, where (Dirty paper (DP)) coding module of the cognitive encoder S4, may combine data bits processed at FPGA unit S2, and control bits processed from the DSP unit S3. The cognitive encoder S4 may be designed with FPGAs-Zynq. The FPGA unit S2 and DSP unit S3 may be designed with DSPs. The cognitive encoder S4 is hereinafter interchangeably referred to as the encoder unit S4.
The cognitive encoder S4 may be configured to encode and combine each of the plurality of data bits and the plurality of control bits received from the plurality of units S2 and S3 and generate a codeword (C’). The codeword (C’) may correspond to the plurality of control bits that may be modified by the cognitive encoder S4, as will be explained hereinafter. Accordingly, the codeword (C’) generated may be as close to the plurality of data bits (D) as possible. The cognitive encoder S4 may transmit the combinedly encoded each of the plurality of data bits and the plurality of control bits and codeword (C’) via the Radio Frequency (RF) transmitter channel S5 to the RF receiver channel S6. The encoding through cognitive encoder S4 has been explained in detail with respect to Figure 2.
The cognitive encoder S4 may transmit the combinedly encoded each of the plurality of data bits and the plurality of control bits via the RF transmitter channel S5, a single antenna, and a power amplifier (PA) S17. The RF transmitter channel S5 may include a direction amplifier (DA), the PA S17, a coupler, and RF filters that tune for the transmitting frequency. Additionally, the RF transmitter channel S5 through the coupler, RF filter, directional amplifier (DA), and RF transceiver may be configured to sense the frequency band of interest for the spectrum sensing requirements and transmit the combined signal for the plurality of control bits and the plurality of data bits.
In this instance, the combinedly encoded each of the plurality of data bits and the plurality of control bits may be tuned and transmitted to the RF receiver channel S6. In an example, the PA S17 may amplify the signal during the transmission before the system S1 sends the signal into air. Finally, antennas or the single antenna may receive the combinedly encoded each of the plurality of data bits and the plurality of control bits from the RF transmitter channel S5, to the PA S17. Further, PA S17 may transmit the output of PA S17 including the combinedly encoded each of the plurality of data bits and the plurality of control bits into the RF receiver channel S6. The combinedly encoded each of the plurality of data bits and the plurality of control bits and codeword (C’) is hereinafter interchangeably referred to as the combinedly encoded signal.
The RF receiver channel S6 may constitute an Automatic Gain Controller (AGC), a tunable filter S12, a Low Noise Amplifier (LNA) for reception, a DPST switch S7, and a power divider S8.
The RF receiver channel S6 may receive the combinedly encoded each of the plurality of data bits and the plurality of control bits and the codeword (C’). The tunable filter S12 may be configured to tune the combinedly encoded each of the plurality of data bits and the codeword (C’), received from the RF transmitter channel S5 to the varying carrier frequency of Frequency hopping (FH) set. The FH set may contain a list of multiple frequencies list sensed by all the radios in the network shared among them with mutual concern to use for communication. The FH set may support reliable communication in case of jamming or any interrupted communication scenarios. In other words, the tunable filter S12 may be configured to tune the combinedly encoded signal received from the RF transmitter channel S5, to the varying carrier frequency of Frequency hopping (FH) set and transmit to the AGC. Further, LNA and Automatic Gain Control (AGC) may assist in conserving the receiver sensitivity to retrieve the data signal without missing the information.
The DPST switch S7 may differentiate the actual data reception which is to be further processed by a cognitive decoder S9 from the spectrum sensing. In other words, the DPST switch S7 may be configured to differentiate the actual data reception indicative of the plurality of control bits and the plurality of data bits from spectrum sensing reception indicative of spectrum occupancy information. Power divider S8 may split the received signal to perform spectrum sensing and data reception in the receiver baseband module S15. In other words, the power divider S8 may be configured to split the received signal, such that spectrum sensing reception may be transferred for spectrum sensing in the receiver baseband module S15 and actual data may be transmitted to the cognitive decoder S9 in the receiver baseband module S15.
The receiver baseband module S15 may include the cognitive decoder S9 and a spectrum sensing module S13. In an example, the cognitive decoder may be based on a Dirty Paper (DP) Model. The receiver baseband module S15 with the DP model based cognitive decoder S9 may decode the combinedly encoded each of the plurality of data bits and the plurality of control bits separately. In an example, the cognitive decoder S9 may be designed using Field-Programmable Gate Array (FPGA).
The cognitive decoder S9 is hereinafter interchangeably referred to as the decoder unit S9.
The cognitive decoder S9 in communication with the cognitive encoder S4 may be configured to receive the combinedly encoded signals via the RF receiver channel S6. The cognitive decoder S9 may decode each of the combinedly encoded signals, such that the decoded each of the plurality of data bits and the plurality of control bits may achieve single channel capacity in the RF receiver channel S6 in the diplex overlay cognitive radio system S1.
In other words, processing of the received data information i.e., the combinedly encoded each of the plurality of data bits and the plurality of control bits and codeword (C’), may be carried out by the cognitive decoder S9 to decode the plurality of data bits S11 and the plurality of control bits S10. The received data information i.e., the combinedly encoded each of the plurality of data bits and the plurality of control bits and codeword (C’) is hereinafter interchangeably referred to as the received signal.
The spectrum sensing module S13 may extract the spectrum occupancy information from the received signal. Further, the processing of the received spectrum occupancy information may be carried out at the spectrum sensing module S13 of the receiver baseband module S15. The system S1 may learn about the spectrum in its environment through the RF receiver channel S6 and may adjust according to the environment and may share the knowledge of the spectrum with the neighbors in the network to make uninterrupted data communication happen. The spectrum sensing module S13 may be developed with FPGA which may have both a Verilog hardware language (VHDL) processor and a Digital Signal Processing (DSP). The spectrum sensing module S13 may be developed with FPGA, such as Zynq processors.
The S14 of Figure 1, which includes the cognitive encoder S4 with the DP coding model, is explained in detail in Figure 2.
Figure 2 illustrates the cognitive encoder S4, according to an exemplary implementation of the present disclosure. Figure 2 presents the details of the Dirty Paper coding encoder of the system S1 of Figure 1.
The cognitive encoder S4 may include a shaping gain module S20, a coding gain module S21, the jointly typical encoder S22, a quadrature amplitude modulation (QAM) unit S23, a partial interference pre-subtraction (PIP) module S25, and a modulo operator S24.
The jointly typical encoder S22 may receive a plurality of control bits S19 and a plurality of data bits S18. In an example, the jointly typical encoder S22 may have a Viterbi encoder, that may compare a data bit (D) sequence of the plurality of data bits with the constellation sequence determined by a trellis encoder and the syndrome sequence. Correspondingly, the jointly typical encoder S22 may output the codeword (C’) corresponding to the plurality of control bits S19.The jointly typical encoder S22 may modify the sequence of constellation region selection for the plurality of control bits, such that the resulting codeword (C’) may be as close to the data bits (D) as possible, as explained in foregoing paragraphs.
In respect of the plurality of data bits S18, prior to being transmitted to the jointly typical encoder S22, the plurality of data bits S18 may be multiplied by ‘?’. In an example, ‘?’ may be calculated as the ratio of the power of transmitted ‘signal’ to the power of transmitted ‘signal & interference’ to limit the total transmitted power.
As illustrated in Figure 2, each of the plurality of control bits S19 may be split into an upper part, a middle part, and a lower part. The upper part may be encoded at the shaping gain module S20 prior to being transmitted to the joint encoder S22. The shaping gain module S20 may be configured to maintain distance between constellation points of the upper part. Each constellation point may be indicative of the positions of each of the plurality of control bits on a space signal. The middle part may be uncoded and directly transmitted to the jointly typical encoder S22. Further, the lower part may be transmitted through the coding gain module S21 prior to transmitting to the jointly typical encoder S22. In an example, the coding gain module S21 may be configured to maintain distance between constellation points of the lower part.
In view of the above, the jointly typical encoder S22 may encode the plurality of control bits S19 by distributing them into three parts. In this instance, the upper part may be passed into shaping gain module S20, the lower part into coding gain module S21, and the middle part may be kept uncoded. In an example, both shaping and coding by the shaping gain module S20 and the coding gain module S21, respectively may be done with the help of a Trellis encoder and Tomlinson-Harashima Precoding (THP). In other words, the upper part, the middle part, and the lower part may be transmitted to the jointly typical encoder S22, where the Trellis and THP method may be applied. The encoding by the coding gain module S21 and the shaping gain module S20 may help the signal to recover with good channel gain and no shaping loss, respectively.
The upper part, the middle part, and the lower part may be transmitted to the jointly typical encoder S22, such that the jointly typical encoder S22 may generate the codeword (C’), corresponding to the plurality of control bits, and encode and combine each of the plurality of data bits and the codeword (C’). Thus, summarizing, the upper part, middle part, and the lower part, separated from the plurality of control bits, may be processed by the jointly typical encoder S22.In other words, the cognitive encoder S4 as shown in Figure 2 may be configured to encode each of the plurality of control bits (C) (S19) through segregating the plurality of control bits S19 to the upper part, the middle part and the lower part. The upper part, may be encoded at the shaping gain module S20. The middle part, may be uncoded. Further, the lower part, may be transmitted through the coding gain module S21 prior to being transmitted to the jointly typical encoder S22. The upper part, the middle part, and the lower part may be jointly encoded at the jointly typical encoder S22, such that the jointly typical encoder S22 may generate the codeword (C’). The codeword (C’) associated with the jointly coded the upper part, the middle part, and the lower part may be as close to the plurality of data bits (D).
The jointly typical encoder S22 may process the plurality of control bits in a manner to form constellation points in the same channel capacity as the other two parts coded with the Trellis and THP techniques. Further, an output from the jointly typical encoder S22 output may be added with the plurality of data bits S18 at the QAM unit S23.
The output of the jointly typical encoder S22 and shaping gain coded part of control bits may be passed to XOR operation.
The jointly typical encoder S22 may transmit the combinedly encoded each of the plurality of data bits, the control bits, and the codeword (C’) to the RF transmitter channel S5 via the QAM unit S23, the PIP module S25, and the modulo operator S24.
The modified bits (C’) corresponding to the codeword C’ along with the combinedly encoded each of the plurality of data bits, may be passed to QAM modulation block S23. The QAM unit S23 may be configured to modulate the combinedly encoded each of the plurality of data bits and the codeword (C’) received from the jointly typical encoder S22. Further, the QAM unit S23 may transmit a combined signal for the combinedly encoded each of the plurality of data bits and the codeword to PIP module S25.
The PIP module S25 may be configured to scale the combined signal by pre-subtracting a fraction of the plurality of data bits from the combined signal received from the QAM unit S23 and transmitted to the modulo operator S24. Instead of subtracting the data bits ’D’ directly from the output of the QAM unit S23, a pre-subtraction of ?D, may be carried out at the PIP module S25.Thus, a data signal i.e., the combined signal may be scaled by the factor of ‘?’, where ? € [0,1] may be subtracted from modulated control bits from the combined signal at the PIP unit S25.In other words, the PIP unit S25 may, instead of subtracting the data bits ’D’ directly from the output of the QAM unit S23, may pre-subtract ?D, where ?? [0, 1]). By choosing ? < 1, the combined noise in the combined signal may be made smaller than a Gaussian noise Z alone. At the other end, the receiver may multiply the received signal corresponding to the plurality of data bits by ‘?’ before applying the modulo operation.
The plurality of control bits and the plurality of data bits may co-exist, and some interference may exist there between. The transmitted power may be distributed between each of the control bit and data bit with the help of ‘?’ to avoid interference at the RF receiver channel S6. In this regard, instead of erasing the interference, some power may be invested in aligning with each other. Additionally, a rate of transmission for the plurality of data bits is based on a power of each of the plurality of data bits and noise power, and a rate of transmission for the plurality of data bits is based on a power of each of the plurality of control bits and noise power.
The modulo operator S24 may be configured to spread the combined signal received from the PIP module S25 with a pre-defined distance and transmit to the RF transmitter channel S5. In this instance, the modulo operator S25 may ensure that there is no overlap between the plurality of control bits and the plurality of data bits, that have been encoded and processed in the combined signal.
In view of the above, the QAM unit S23 may modulate the combined signal of joint symbols of the plurality of data bits and the plurality of control bits, and may transmit to the modulo operator S24. The modulo operator S24 may separate QAM constellation points by mod?. Modulo operation S24 may spread signal in the constellation with the distance of ? = v(?M d?_min ). Additionally, the modulo function by the modulo operator S25 may collapse all points different of ? to the same value, such that constellation points may be seen as multiple representations of the same constellation point. In order to avoid shaping gain, coding gain losses, and to recover the signal at the receiver, the constellation points may be separated by dmin. Accordingly, error while decoding (as illustrated in the foregoing paragraphs) may be reduced and any losses incurred due to shaping gain and coding gain may be avoided.
The output of the modulus operator S24 may be passed to the RF transmitter channel S5 and transmitted with the single antenna. As illustrated above, the received signal i.e., the combinedly encoded signal at the RF receiver channel S6, may be passed to receiver baseband module S15. In the receiver baseband module S15, the spectrum sensing module S13 may extract the spectrum occupancy information from the received signal and the cognitive decoder S9 may decode the plurality of control bits and the plurality of data bits.
Figure 3 illustrates coding gain blocks S22, and S23, according to an exemplary implementation of the present disclosure.
An example of constellation mapping of the plurality of data bits (D) S26, and of the plurality of control bits (C) S27 and modified control bits (C’) S28 is illustrated in Figure 3. The dots as illustrated in Figure 3 illustrate the points of constellation.
As mentioned above, the shaping gain module S20 may be configured to maintain distance between constellation points of the upper part. Each constellation point may be indicative of the positions of each of the plurality of control bits on a space signal. Further, the coding gain module S21 and the jointly typical encoder S22 may maintain the same in constellation form for further modulation of the combined signal to avoid interference between the plurality of control bits and the plurality of data bits.
Thereafter, the combined signal may be mapped through QAM mapping, such that there is no overlap. Further, mapping may be done through the modulation technique on the constellation points by the modulus operator S24.
In other words, the effect of modulus operator S24 may help in forming constellation points, as shown in Figure 3 to minimize the loss caused, dmin’ distance may be maintained. As illustrated, a distance between each constellation point may be a minimum distance of ‘dmin’ distance that may have been required to be maintained to avoid interference there between.
Figure 4 illustrates the cognitive decoder S9, according to an exemplary implementation of the present disclosure.
Figure 4 explains the cognitive decoder 9 of Figure 1.
As stated above, the cognitive decoder S9 at the receiver baseband module S15 may receive the combinedly encoded each of the plurality of data bits and the plurality of control bits.
Corresponding to the transmitter baseband module S14, the receiver baseband module S15 may constitute corresponding module operator S29, a trellis decoder S30, control bit decoder S31, a data bit decoder S32, a shaping gain decoder module S33, and a coding gain decoder module S34 to derive actual control bits “C” S35 and actual data bits
“D" S36. The trellis decoder S30 corresponds to the cognitive decoder S9.
The signal received from the RF receiver channel S6 may be passed and multiplied by the factor of ‘?’ at the receiver baseband module S15 again to reduce the loss due to an interference signal.
The cognitive decoder S9 may segregate combinedly encoded each of the plurality of data bits and the plurality of control bits, separately, via the module operator S29, and the trellis decoder S30. The modulus operator S29 may remove the decoding error and may restrict the received power in case of high interference scenarios. In an example, the decoding error may be any error present or may occur while mapping that may cause a possibility of the constellation points collapsing. The signal received may be divided at the Trellis decoder S30 into two signals.
In the receiver baseband module S15, the control bits may be decoded in a control bit decoder path. The control bit decoder path may include THP-based modulo ? operator S29 followed by Trellis decoder S30. The received bits may be recovered with a usual trellis decoder S30. The cognitive decoder S9 may also employ the Trellis shaping scheme to decode the control bits and achieve channel capacity for control bits as RC.
Further, in the receiver baseband module S15, the data bits may be decoded in a data bit decoder path. The data bit decoder path may include modulo ? operator S29 followed by the trellis de-mapper to decode the data bits and achieve channel capacity for data bits as RD.
Thereafter, the plurality of control bits may be passed to the control bit decoder S31 and the plurality of data bits may be passed to the data bit decoder S32.
In this regard, the cognitive decoder S9 may decode the segregated plurality of control bits via the control bit decoder S31. Further, the control bit decoder S31 may include the shaping gain decoder module S33 and the coding gain decoder S34 to achieve the channel capacity in the same RF channel i.e., the receiver baseband module S15. At control bit decoder S31, the plurality of control bits may be passed into the shaping gain decoder module S33 and the coding gain decoder module S34 to derive the actual control bits “C” S35.
Further, the cognitive decoder S9 may decode the segregated plurality of data bits via a data bit decoder module to achieve the channel capacity in the same RF channel S15. The plurality of data bits passed to the data bit decoder S32 to derive the actual data bits “D” S36.
In view of the above, in the cognitive decoder S9 based on the DP model as shown in Figure 4, the received signal may be multiplied by ‘?’, and mod ? operation may be performed at S29, followed by trellis decoding at S30. Further control bit decoder S31 may decode actual control bits S35 using the shaping gain decoder module S33 and the coding gain decoder module S33. The data bit decoder S32 may decode the actual data bits S36. Thus, data bits and control bits may be decoded separately at the receiver of the diplex cognitive radio.
In view of the above, the DP model may combine the plurality of control bits and the plurality of data bits and may further, map both signals in a way, such that both are transmitted using the single RF channel and throughput may not compromised. The dirty paper model in the present disclosure may be based on DP coding, i.e., an advanced interference cancellation technique. In comparison to the existing art, in conventional systems in case interference is present along with legitimate signal, the conventional system may spend its transmitted power and may try to erase the interference from signal and may spend remaining power to transmit the required signal. Contrary to the conventional techniques, the DP model of the present disclosure having DP coding technique may assume that the interference may be non-causally known at the cognitive encoder S4. Accordingly, some portion of transmitted power may be spent in aligning with the interference signal instead of cancelling the interference from signal. Further, the DP model of the present disclosure may recover signals by using advanced decoding techniques and decode the signal properly. On the contrary, in the existing art with respect to the DP coding technique, in an instance when the interference is known at the transmitter, the channel capacity of the conventional system may not be affected by the known interference signal and channel capacity may remain same as that of Shannon limits of Additive White Gaussian Noise (AWGN) channel. In the conventional communication system if ‘X’ is the transmitted signal, S’ is interference signal, then the received signal ‘Y’ will be Y=X+Z+S, where ‘Z’ is the AWGN channel noise, and the achievable Shannon channel capacity is:

Where, PX may be the power of transmitted signal, PS may be the power of interference signal and PZ may be the AWGN channel noise power.
In a conventional cognitive radio system, where in case ‘D’ and ‘C’ are transmitted together, and not known to each other at the transmitter, then the received signal a will be Y= D+Z+C and achievable channel capacity RD of data bits and RC of control bits as per Shannon capacity limit will be
R_D= 1/2 ln(1+ P_D/(P_Z+ P_C )) ……. Equation (3)
and
R_C= 1/2 ln(1+P_C/(P_Z+P_D ))……. Equation (4),
where PD may be the power of data bits, PC may be the power of control bits and PZ may be the AWGN channel noise power.
In case of the present disclosure, with the help of the cognitive encoder S4, Costa theorem may be exercised to transmit control and data bits jointly. As both signal “C” and “D” are known interference for each other, as per Costa theorem mentioned in equation 2, Shannon channel capacity may not be affected by the interference added and may be same as AWGN channel. Hence if ‘C” and “D” are considered as mutual interference to each other and known at transmitter, then the achievable channel capacity for data at the proposed system may be:
R_D= 1/2 ln(1+P_D/P_Z )=C_AWGN-------- equation 5.
Further, channel capacity of control bits may be,
R_C= 1/2 ln(1+P_C/P_Z )=C_AWGN-------- equation 6.
Thus, achieving the same channel capacity by joint transmission of control and data using diplex overlay cognitive radio.
In view of the above, the diplex overlay cognitive radio system S1 of the present disclosure is directed towards transmitting control and data information jointly without compromising the ‘data’ throughput and being able to fully recover the control and data information separately at its receiver. The system S1 of the present disclosure may transmit control and data information jointly and receive at the receiver by mitigating the interferences created to each other by using advanced encoding-decoding methods such as DP model. Like TDMA or dual RF channel, the system S1 of the present disclosure will not result in comprising throughput or increasing the hardware complexity.
Further, the cognitive decoder S9 decode each of the combinedly encoded each of the plurality of data bits and the plurality of control bits in a manner that a data rate associated with the each of the plurality of data bits and the plurality of control bits is same as a data rate of a cognitive radio that transmits data bits and control bits with separate RF irrespective of interference created due to coexistence. Particularly, the data rate achieved by the system S1 of the present disclosure may be same as that of the cognitive radio that transmits data bits and control bits with separate RF irrespective of interference created due to coexistence.
It may be understood that with the CR architecture and encoder/decoder approach of the present disclosure, channel capacity may not be reduced by transmitting the control bit information or there may be no need for an additional RF channel for managing simultaneous transmission of control and data bits.
Thus, the present disclosure provides an advantage that the system of diplex cognitive radio of the present disclosure can transmit control and data information jointly without compromising the ‘data’ throughput and be able to fully recover the control and data information separately at its receiver.
In view of the above, the CR architecture of the present disclosure may transmit the control message and data message simultaneously using a single RF structure, and without compromising the throughput of the data bit of CR may be achieved through the present disclosure. The Diplex Cognitive Radio architecture 100 of the present disclosure includes the system S1 that suggests techniques for the coexistence of data and control channels. The system S1 employs the advanced interference cancellation method through the Dirty paper model. DP model may include dirty paper coding and algorithms needed for digital communication of cognitive radio done at FPGA in control or data channel for their simultaneous transmissions to happen.
The losses incurred by parallel transmission may be compensated for by three-layer Trellis-based encoding adapted by the present disclosure. Trellis-based encoding may divide the control bits into three portions and each 1/3rd of the control bit is encoded with different gains. Hence a specific decoder is employed for decoding control bits separately and data bits separately. Thus, the CR architecture to transmit control and data jointly has been disclosed by the present disclosure.
The system ensures a combined rate of transmission for the plurality of data bits and plurality of control bits with the single RF transmitter channel S5 will be same as rate of transmission of data bits and control bits in a conventional cognitive radio system with dual RF channel.
While specific language has been used to describe the present disclosure, any limitations arising on account thereto, are not intended. As would be apparent to a person in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein. The drawings and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment.
,CLAIMS:We Claim:

1. A diplex overlay cognitive radio system (S1) comprising:
a transmitter baseband module (S14) comprising a cognitive encoder (S4), wherein the cognitive encoder (S4) is configured to receive a plurality of data bits and a plurality of control bits from a plurality of units (S2, S3) of the transmitter baseband module, wherein the cognitive encoder (S4) is configured to:
encode and combine each of the plurality of data bits and the plurality of control bits; and
transmit the combinedly encoded each of the plurality of data bits and the plurality of control bits via a Radio Frequency (RF) transmitter channel (S5).

2. The diplex overlay cognitive radio system (S1) as claimed in claim 1, wherein the cognitive encoder (S4) is based on a Dirty Paper (DP) Model.

3. The diplex overlap cognitive radio system (S1) as claimed in claim 1, wherein the plurality of units (S2, S3) comprises:
a digital signal processing (DSP) unit configured to generate the plurality of control bits by converting spectrum sensing information received from an RF channel into the plurality of control bits; and
a Field-Programmable Gate Array (FPGA) configured to generate the plurality of data bits.

4. The diplex overlap cognitive radio system (S1) as claimed in claim 3, wherein the cognitive encoder (S4) is configured to encode each of the plurality of control bits (C) (S19) through:
an upper part, which is encoded at a shaping gain module (S20);
a middle part, which is uncoded, and
a lower part, which is transmitted through a coding gain module (S21) prior to being transmitted to a jointly typical encoder (S22),
wherein the upper part, the middle part, and the lower part are jointly encoded at the jointly typical encoder (S22) and such that the jointly typical encoder (S22) generates a codeword (C’), wherein the codeword (C’) associated with the jointly coded the upper part, the middle part, and the lower part is as close to the plurality of data bits (D).

5. The diplex overlap cognitive radio system (S1) as claimed in claim 4, wherein the jointly typical encoder (S22) transmits the combinedly encoded each of the plurality of data bits and the control bits to the RF transmitter channel (S5) via a quadrature amplitude modulation (QAM) unit (S23), a partial interference pre-subtraction (PIP) module (S25), and a modulo operator (S24),
wherein the QAM unit (S23) is configured to modulate, the combinedly encoded each of the plurality of data bits and the codeword (C’) received from the jointly typical encoder (S22) and transmit a combined signal for the combinedly encoded each of the plurality of data bits and the codewords to PIP module (S25),
wherein the PIP module (S25) is configured to scale the combined signal by pre-subtracting a fraction of the plurality of data bits from the combined signal received from the QAM unit (S23) and transmit to the modulo operator (S24),
wherein the modulo operator (S24) is configured to spread the combined signal received from the PIP module (S25) with a pre-defined distance and transmit to the RF transmitter channel (S5).

6. A diplex overlay cognitive radio system (S1) comprising:
a receiver baseband module (S15) comprising a spectrum sensing module (S13) and cognitive decoder (S9), wherein the cognitive decoder (S9) is configured to:
receive a combinedly encoded each of a plurality of data bits and a plurality of control bits via a RF receiver channel (S6); and
decode each of the combinedly encoded each of the plurality of data bits and the plurality of control bits such that the decoded each of the plurality of data bits and the plurality of control bits achieves channel capacity in the RF receiver channel (S6) in the diplex overlay cognitive radio system (S1).

7. The diplex overlay cognitive radio system (S1) as claimed in claim 6, wherein the cognitive decoder (S9) is based on a Dirty Paper (DP) Model.

8. The diplex overlap cognitive radio system (S1) as claimed in claim 6, wherein the cognitive decoder (S9) is configured to:
segregate each of the combinedly encoded each of the plurality of data bits and the plurality of control bits, separately, via a module operator (S29), and a trellis decoder (S30);
decode the segregated plurality of control bits via a control bit decoder (S31), wherein the control bit decoder (S31) comprises a shaping gain decoder module (S33) and a coding gain decoder module (S34); and
decode the segregated plurality of data bits via a data bit decoder (S32) module.