Description:TECHNICAL FIELD [01] The present disclosure, in general, relates to managing calibration of radio frequency (RF) components in a wireless communication network, and in particular, relates to systems and methods for calibration of transmit chains in a wireless communication device, for example, a base station. BACKGROUND [02] A fifth-generation (5G) new radio (NR) base station (BS) supports high peak data rates with better reliability to multiple users simultaneously in a larger coverage area. The key enabler for such support is massive multiple-input-multiple-output (MIMO) technology. It provides several techniques to boost the performance of the BS, such as spatial diversity to enhance transmission robustness, spatial multiplexing to improve the peak data rates, and beamforming to increase signal-to-noise ratio (SNR). To get full advantages of MIMO techniques, the radio paths should have identical characteristics, such as having same gain and phase responses with same group delay. However, the actual radio paths have different characteristics due to different components and radio frequency (RF) paths. The characteristics of the radio path may also be affected by temperature variations during actual data transmission. Thus, calibration of the radio paths is required to ensure consistent MIMO performance. [03] For antenna calibration, usually time-frequency resources are reserved by higher layers and user data transmission on the reserved resources is halted during the calibration process. This reduces spectrum efficiency of the BS, especially when the calibration is set to repeat periodically. Hence, there is a need for a system and a method to maintain high spectrum efficiency without disturbing the user data transmission during the calibration. During an operating phase or data transmission, the BS may implement the antenna calibration from time to time to check an integrity of estimated calibration coefficients. This repetition may be referred to as calibration periodicity. Generally, the calibration is set to repeat after regular intervals, referred to as periodic calibration. The periodic calibration with lower periodicity may increase the processing overhead of a system, while higher periodicity may reduce effectiveness of the calibration process. [04] FIGs. 1A-1C illustrate system architecture for antenna calibration. [05] FIG. 1A depicts an ideal scenario where all transmit chains have similar characteristics. FIG. 1B depicts a base station with no calibration logic. FIG. 1C depicts the base station with an internal antenna calibration block. [06] Antenna calibration requires a loopback mechanism, which may be over-the-air (OTA) or an internal dedicated feedback path. OTA calibration may require a receiver or a user equipment (UE) which may not be available during the calibration, especially in a start-up/bootup phase of the BS. Moreover, the OTA calibration requires receive chains to capture the signal used for calibration of the transmit chains. If the receive chains are not calibrated, then precise transmit chain calibration may not be implemented. Moreover, a hardware design of the transmit and receive chains may not be symmetrical, which may also lead to non-optimal calibration. While the calibration with the internal dedicated feedback path does not suffer from such issues, it requires additional resources whose functionalities again need to be optimized for enhanced performance. [07] The existing systems do not offer any efficient mechanism for antenna calibration of the 5G NR MIMO BS with low processing complexity while maintaining spectrum efficiency. Therefore, there is, a need for a system and a method to calibrate the RF paths at a start-up phase and during an operating phase of the 5G NR MIMO BS adaptively without impacting user data transmission. OBJECTS OF THE PRESENT DISCLOSURE [08] It is an object of the present disclosure to provide a system and a method to calibrate Radio Frequency (RF) paths at a start-up phase and during an operating phase of a fifth-generation (5G) new radio (NR) base station (BS) adaptively without impacting user data transmission. [09] It is an object of the present disclosure to provide a system and a method to calibrate RF transmission paths during run-time of a communication apparatus, i.e., calibration of RF transmission path in between data transmission without affecting a data transmission rate. [010] It is an object of the present disclosure to provide a system and a method for handling variation in temperature and processing delay between multiple RF transmission paths. [011] It is an object of the present disclosure to provide a system and a method to adaptively calibrate RF transmit chains in a multiple-input-multiple-output (MIMO) communication apparatus which also utilizes resources optimally and effectively. SUMMARY [012] In an aspect, the present disclosure relates to a method for calibration of transmit chains in a start phase of a base station. The method includes setting, by a controller, delay values to zero and calibration coefficients to unity with zero phase for each of a plurality of transmit chains. The method includes setting, by the controller, a first multiplexer to send orthogonal sequences on each of the plurality of transmit chains. The method includes obtaining, by the controller, a first summed signal of the plurality of transmit chains. The method includes estimating, by the controller, a first response and a first time delay for each of the plurality of transmit chains by cross-correlating the first summed signal with an orthogonal sequence. The method includes computing, by the controller, calibration coefficients and delay values for each of the plurality of transmit chains based on the estimated first response to mitigate relative gain and phase differences with respect to a given transmit chain. [013] In an embodiment, the method may include setting, by the controller, a second multiplexer to send frequency domain equivalent of the orthogonal sequences on each of the plurality of transmit chains. The method may include applying, by the controller, the computed calibration coefficients on the frequency domain equivalent of the orthogonal sequences to obtain calibrated sequences. The method may include performing, by the controller, Orthogonal Frequency-Division Multiplexing (OFDM) modulation on the calibrated sequences. The method may include controlling, by the controller, the first time delay in each of the plurality of transmit chains by adjusting a timing of the calibrated sequences. [014] In an embodiment, the method may include setting, by the controller, the first multiplexer to send the calibrated sequences on each of the plurality of transmit chains. The method may include obtaining, by the controller, a second summed signal of the plurality of transmit chains. The method may include estimating, by the controller, a second response and a second time delay for each of the plurality of transmit chains. The method may include computing, by the controller, a gain difference, a phase difference, and a timing delay difference of each of the plurality of transmit chains with respect to the given transmit chain, based on the estimation. The method may include comparing, by the controller, the gain difference, the phase difference, and the timing delay difference of each of the plurality of transmit chains with a gain error threshold, a phase error threshold, and a delay error threshold, respectively. [015] In an embodiment, responsive to at least one of the gain difference, the phase difference, and the timing delay difference of each of the plurality of transmit chains being less than the gain error threshold, the phase error threshold, and the delay error threshold, respectively, the method may include storing, by the controller, the computed calibration coefficients and the delay values in a database associated with the base station to perform calibration of the plurality of transmit chains. [016] In an embodiment, responsive to at least one of the gain difference, the phase difference, and the timing delay difference of each of the plurality of transmit chains being greater than the gain error threshold, the phase error threshold, and the delay error threshold, respectively, the method may include computing, by the controller, updated calibration coefficients and/or updated delay values for each of the plurality of transmit chains based on the estimated response to mitigate the gain difference, the phase difference, or the timing delay difference with respect to the given transmit chain. [017] In an aspect, the present disclosure relates to a method for calibration of transmit chains in a base station. The method includes determining, by a controller, that user data transmission is initiated in an operating phase of the base station. The method includes determining, by the controller, a need for calibration of a plurality of transmit chains in the base station. In response to the determination, detecting, by the controller, an arrival of at least one of: a guard period of a special time slot in a Time-Division Duplex (TDD) radio frame, or an Orthogonal Frequency-Division Multiplexing (OFDM) symbol allocated by one or more higher layers in a Frequency Division Duplex (FDD) radio frame. The method includes performing, by the controller, fine-tuned calibration of each of the plurality of transmit chains based on the detection. [018] In an embodiment, determining, by the controller, the need for the calibration of the plurality of transmit chains may be based on at least one of: an expiry of a timer, a request by the one or more higher layers, an event of a change in temperature, and a fault being identified in a given transmit chain of the plurality of transmit chains. [019] In an embodiment, performing, by the controller, the fine-tuned calibration of each of the plurality of transmit chains may include, for each of the plurality of transmit chains, setting, by the controller, a first multiplexer to send orthogonal sequences on the plurality of transmit chains. The method may include applying, by the controller, calibration coefficients on the orthogonal sequences to obtain calibrated sequences, where the calibration coefficients are computed during a start phase of the base station or during earlier stages of the operating phase. The method may include performing, by the controller, OFDM modulation on the calibrated sequences, The method may include controlling, by the controller, a delay in each of the plurality of transmit chains by adjusting a timing of the calibrated sequences. [020] In an embodiment, the method may include setting, by the controller, a second multiplexer to send the calibrated sequences on the plurality of transmit chains. The method may include obtaining, by the controller, a summed signal of the plurality of transmit chains. The method may include estimating, by the controller, a response and a time delay of each of the plurality of transmit chains by cross-correlating the summed signal of the plurality of transmit chains with an orthogonal sequence. The method may include computing, by the controller, a gain difference, a phase difference, and a timing delay difference of each of the plurality of transmit chains with respect to a given transmit chain, based on the estimation. The method may include comparing, by the controller, the gain difference, the phase difference, and the timing delay difference of each of the plurality of transmit chains with a gain error threshold, a phase error threshold, and a delay error threshold, respectively. [021] In an embodiment, responsive to at least one of the gain difference, the phase difference, and the timing delay difference of each of the plurality of transmit chains being less than the gain error threshold, the phase error threshold, and the delay error threshold, respectively, the method may include storing, by the controller, the calibration coefficients in a database associated with the base station to perform the fine-tuned calibration of each of the plurality of transmit chains. [022] In an embodiment, responsive to at least one of the gain difference, the phase difference, and the timing delay difference of each of the plurality of transmit chains being greater than the gain error threshold, the phase error threshold, and the delay error threshold, respectively, the method may include computing, by the controller, updated calibration coefficients for each of the plurality of transmit chains based on the estimated response. The method may include detecting, by the controller, an arrival of at least one of: a guard period of a consecutive special time slot in the TDD radio frame, or an OFDM symbol allocated by the one or more higher layers in the FDD radio frame. The method may include performing, by the controller, the fine-tuned calibration of each of the plurality of transmit chains based on the detection. [023] In an embodiment, the guard period may correspond to a first guard period of the special time slot. [024] In an embodiment, the fine-tuned calibration may include at least an adaptive calibration, and for the adaptive calibration, the method may include adaptively controlling, by the controller, a value of the timer for performing the fine-tuned calibration of the plurality of transmit chains. [025] In an aspect, the present disclosure relates to a base station for calibration of transmit chains in a start phase. The base station includes a controller associated with a processor, and a memory operatively coupled to the processor. The memory includes processor-executable instructions which, when executed by the processor, cause the controller to set delay values to zero and calibration coefficients to unity with zero phase for each of a plurality of transmit chains. The controller sets a first multiplexer to send orthogonal signal sequences on each of the plurality of transmit chain. The controller obtains a first summed signal of the plurality of transmit chains. The controller estimates a first response and a first time delay for each of the plurality of transmit chains by cross-correlating the first summed signal with an orthogonal sequence. The controller computes calibration coefficients for each of the plurality of transmit chains based on the estimated first response to mitigate relative gain and phase differences with respect to a given transmit chain. [026] In an aspect, the present disclosure relates to a base station for calibration of transmit chains in an operating phase. The base station includes a controller associated with a processor, and a memory operatively coupled to the processor. The memory includes processor-executable instructions which, when executed by the processor, cause the controller to determine that user data transmission is initiated in the operating phase of the base station, and determine a need for calibration of a plurality of transmit chains in the base station. In response to the determination, the controller detects an arrival of at least one of a guard period of a special time slot in a Time-Division Duplex (TDD) radio frame, and an Orthogonal Frequency-Division Multiplexing (OFDM) symbol allocated by one or more higher layers in a Frequency Division Duplex (FDD) radio frame, and perform fine-tuned calibration of each of the plurality of transmit chains based on the detection. [027] In an embodiment, the controller may perform the fine-tuned calibration of each of the plurality of transmit chains by being configured to combine signals of each of the plurality of transmit chains, and estimate a response and a time delay for each of the plurality of transmit chains. BRIEF DESCRIPTION OF DRAWINGS [028] The accompanying drawings, which are incorporated herein, and constitute a part of this disclosure, illustrate exemplary embodiments of the disclosed methods and systems which like reference numerals refer to the same parts throughout the different drawings. Components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Some drawings may indicate the components using block diagrams and may not represent the internal circuitry of each component. It will be appreciated by those skilled in the art that disclosure of such drawings includes the disclosure of electrical components, electronic components, or circuitry commonly used to implement such components. [029] FIGs. 1A-1C illustrate conventional system architecture for antenna calibration in a 5th Generation (5G) Multiple Input Multiple Output (MIMO) base station. [030] FIG. 2 illustrates an exemplary system architecture for antenna calibration with a calibration port inside an antenna panel, in accordance with an embodiment of the present disclosure. [031] FIG. 3 illustrates an exemplary system architecture for antenna calibration with no calibration port inside an antenna panel, in accordance with an embodiment of the present disclosure. [032] FIG. 4A illustrates an exemplary representation of a 5G New Radio (NR) Time Division Duplex (TDD) radio frame, in accordance with an embodiment of the present disclosure. [033] FIG. 4B illustrates an exemplary representation for implementing calibration in a special slot with two guard periods, in accordance with an embodiment of the present disclosure. [034] FIG. 4C illustrates an exemplary representation for implementing calibration in a special slot with four guard periods, in accordance with an embodiment of the present disclosure. [035] FIG. 5 illustrates a high-level flow chart of an exemplary method for antenna calibration of transmit chains, in accordance with an embodiment of the present disclosure. [036] FIG. 6 illustrates a flow chart of an exemplary method for coarse calibration of transmit chains during a start-up phase of a base station, in accordance with an embodiment of the present disclosure. [037] FIG. 7 illustrates an exemplary representation of ZadoffChu sequences for different transmit chains in a base station, in accordance with an embodiment of the present disclosure. [038] FIG. 8 illustrates a flow chart of an exemplary method for implementing fine-tuned calibration of transmit chains during an operating phase of a base station, in accordance with an embodiment of the present disclosure. [039] FIG. 9 illustrates an exemplary representation of fine-tuned calibration in two special slots, in accordance with an embodiment of the present disclosure. [040] FIG. 10A illustrates an exemplary representation of a gain plot of an estimated value of transmit chain responses before calibration, in accordance with an embodiment of the present disclosure. [041] FIG. 10B illustrates an exemplary representation of a gain plot of an estimated value of transmit chain responses after calibration, in accordance with an embodiment of the present disclosure. [042] FIGs. 11A and 11B illustrate exemplary representations of a gain plot of signal at different antenna ports without antenna calibration, in accordance with an embodiment of the present disclosure. [043] FIGs. 12A and 12B illustrate exemplary representations of a gain plot of signal at different antenna ports with antenna calibration, in accordance with an embodiment of the present disclosure. [044] FIGs. 13A and 13B illustrate exemplary representations of a phase plot of signal at different antenna ports without antenna calibration, in accordance with an embodiment of the present disclosure. [045] FIGs. 14A and 14B illustrate exemplary representations of a phase plot of signal at different antenna ports with antenna calibration, in accordance with an embodiment of the present disclosure. [046] FIG. 15 illustrates an exemplary computer system in which or with which embodiments of the present disclosure may be implemented. [047] The foregoing shall be more apparent from the following more detailed description of the disclosure. DETAILED DESCRIPTION [048] In the following description, for the purposes of explanation, various specific details are set forth in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent, however, that embodiments of the present disclosure may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. An individual feature may not address all of the problems discussed above or might address only some of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein. [049] The ensuing description provides exemplary embodiments only and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the disclosure as set forth. [050] The various embodiments throughout the disclosure will be explained in more detail with reference to FIGs. 2-15. [051] FIG. 2 illustrates an exemplary system architecture (200) for antenna calibration with a calibration port (220a) inside an antenna panel (220), in accordance with an embodiment of the present disclosure. [052] In particular, the exemplary system architecture (200) may represent a communication system such as a 5th Generation (5G) or next-generation communications system (200). As depicted, the architecture (200) includes different antenna panels (220) in which an in-built calibration port (220a) is provided. The calibration port (220a) may provide a summed output of small portion of signals coming inside the antenna panels (220) or Radio Frequency (RF) antenna ports of the antenna panel (220). The system architecture (200) may be utilized in both types of base stations, which have antenna panels (220) with and without in-built calibration ports (220a). [053] In an embodiment, the system architecture (200) may include a System on Chip (SoC) (202). The SoC (202) may include a processing system (or interchangeably referred to as a processor) and a programming logic for baseband processing of incoming data and other control functions. [054] In an embodiment, user data (204) may be in the form of a frequency domain modulated in-phase (I) and quadrature (Q) symbols from higher layers of the base station. The higher layers may be a high Physical (PHY) layer including, but not limited to, Media Access Control (MAC) and Radio Link Control (RLC) layers. [055] In an embodiment, a memory bank (206) may include orthogonal sequences with its circularly shifted sequences on a time domain (ZT) and their frequency domain equivalent (ZF) for calibration coefficients. [056] In an embodiment, a second multiplexer (MUXF) (208) may switch between the user data (204) and the orthogonal sequence from the local memory bank (206) in the frequency domain. Examples of the orthogonal sequences may include, but not limited to, Constant Amplitude Zero Auto-Corelation waveform (CAZAC) signal, ZadoffChu sequence (Z), Walsh-Hadamard code, etc. [057] In an embodiment, a calibrator (210) may contain complex multipliers to multiply the frequency domain data with calibration coefficients to compensate for gain, phase, and timing differences with respect to a reference chain. [058] In an embodiment, an Orthogonal Frequency Division Multiplexing (OFDM) modulator (212) may perform inverse Fast Fourier transform (iFFT) and cyclic prefix addition operations. [059] In an embodiment, a delay adjuster (234) may delay time domain data with estimated delay values to compensate for the timing differences with respect to the reference chain. [060] In an embodiment, a first multiplexer (MUXT) (214) may switch between the calibrated data and the orthogonal sequence (ZT) from the local memory bank (206) in the time domain. [061] In an embodiment, a Digital Front End (DFE) and a digital to analog converter (DAC) (216) may pre-distort and upconvert the incoming time-domain IQ symbols and then convert them to an analog domain. [062] In an embodiment, Radio Frequency (RF) module (218) may process the signal with a series of RF components. The RF module (218) may amplify the signal with the series of RF components with a desired output power before transmission. [063] In an embodiment, the antenna panel (220) may radiate the RF signals for transmission. As discussed herein, the antenna panel (220) may include the in-built calibration port (220a), which provides a summed output of a portion of the signal input to all RF antenna ports. [064] In an embodiment, a feedback network (222) may include a series of attenuators to keep the power level of the feedback signal in an operating range of an observation (ORX) analog to digital converter (ADC) (224). [065] In an embodiment, a DFE and ORX-ADC (224) may convert the analog signal to a digital signal and then down-convert the digital signal. [066] In an embodiment, a response and delay estimator (226) may estimate the response and time delay of all transmit chains. [067] In an embodiment, an OFDM demodulator (228) may perform cyclic prefix removal and Fast Fourier Transform (FFT) operations. [068] In an embodiment, a coefficient estimator (230) may estimate the calibration coefficients for antenna calibration based on the estimated response and time delay of all transmit chains. [069] In an embodiment, a controller (232) may control the whole operation of the antenna calibration. During a start-up phase, the controller (232) may initially identify a control signal (c1) to reset the calibration coefficients. The controller (232) may identify the control signal (c1) to update the coefficients with their estimated value during the rest of the start-up phase and the operating phase. The controller (232) may identify the control signals, c2 and c3 to control the first multiplexer (MUXT) (214) and the second multiplexer (MUXF) (208), respectively. [070] The controller (232) may take an input from the response and delay estimator (226) to calculate a gain difference (Eg), a phase difference (Ep), and a timing delay difference (Ed) for each transmit chain with respect to the reference chain. The controller (232) may compare the gain difference (Eg), the phase difference (Ep), and the timing delay difference (Ed) with a gain error threshold (Tg), a phase error threshold (Tp), and a delay error threshold (Td), respectively. It may be appreciated that all thresholds may be configurable and may be defined as per design implementation. If the estimation of coefficients is required based on the comparison, the controller (232) may identify a control signal (c4) to inform the coefficient estimator (230) for the estimation of the calibration coefficients. [071] In an embodiment, during the operating phase, the controller (232) may control the periodicity of the calibration by updating a timer value adaptively. [072] FIG. 3 illustrates an exemplary system architecture (300) for antenna calibration with no calibration port inside an antenna panel (220), in accordance with an embodiment of the present disclosure. [073] A person skilled in the art may understand that the various modules mentioned in FIG. 3 may be similar to the corresponding modules of FIG. 2 in their functionality and may not be described again for the sake of brevity. [074] With reference to FIG. 3, a coupler (302) may provide coupled output for a feedback path. In an embodiment, a combining network (304) may include a series of combiners to combine the feedback signal from each transmit antenna. [075] FIG. 4A illustrates an exemplary representation (400A) of a 5G New Radio (NR) Time Division Duplex (TDD) radio frame, in accordance with an embodiment of the present disclosure. [076] With reference to FIG. 4A, considering the 30kHz subcarrier spacing, a 10ms radio frame may include 20 time slots, each having 14 OFDM symbols. The downlink may occupy 14 slots, and the uplink may occupy 4 slots out of 20 slots in normal conditions. The rest of the two slots may be used as special slots. The 14 OFDM symbols in each special slot may be configured as 10 symbols for downlink, 2 symbols for the guard period, and 2 symbols for uplink. To avoid information loss, a base station utilizes the guard period of the special slots to perform the calibration operation during the operating phase. [077] FIG. 4B illustrates an exemplary representation (400B) for implementing calibration in a special slot with two guard periods, in accordance with an embodiment of the present disclosure. [078] With reference to FIG. 4B, if only two guard periods are present in one special slot, then fine-tuned calibration of the transmit chains may be implemented in a first guard period of the current special slot. In another embodiment, the fine-tuned calibration of the transmit chains may be implemented based on a request by higher layers of the base station to increase a size of the guard period to perform the calibration of transmit chains in the same special slot. [079] FIG. 4C illustrates an exemplary representation (400C) for implementing calibration in a special slot with four guard periods, in accordance with an embodiment of the present disclosure. [080] With reference to FIG. 4C, if four or more guard periods are present in one radio frame, then fine-tuned transmit chain calibration may be implemented in the first guard period of the same special slot. [081] FIG. 5 illustrates a high-level flow chart of an exemplary method (500) for antenna calibration of transmit chains, in accordance with an embodiment of the present disclosure. It may be appreciated that the method (500) may be implemented by the base station, i.e. the controller (232) or the processor. [082] The antenna calibration of a 5G NR TDD MIMO base station may measure signal characteristics across the transmit chains, and determine the differences across the transmit chains, specifically in terms of gain, phase, and timing. Further, the antenna calibration may calibrate the transmit signals to mitigate the differences across the transmit chains. The calibration may include two phases, namely a start-up phase and an operating phase. [083] In the start-up phase, the calibration may be implemented during a start-up/booting of the base station. It may be considered as a coarse calibration of the base station as it equalizes the gain, phase, and timing differences across the chains, which may occur due to the system design. In the operating phase, the base station may undergo temperature variations, which may affect the characteristics of the transmit chains. Therefore, the calibration may be required during the operating phase, and thus, it may be considered as a fine-tuned calibration. The temperature variation may become slow once the base station reaches a steady state. Thus, the calibration in the operating phase may not be required frequently. [084] In an embodiment, the base station may be operated with a TDD radio frame to perform the calibration in a guard period during the operating phase without halting the user data transmission. This may provide leverage to the base station to maintain the spectrum efficiency of the TDD system in real-time. In another embodiment, for Frequency Division Duplex (FDD) base station, a request may be sent to the higher layer to provide the configurable number of vacated OFDM symbols for calibration. The higher layer vacates the requested number of OFDM symbols in one or more FDD radio frames and provides the frame number and OFDM symbol number to the base station to perform calibration during the operating phase. [085] With reference to FIG. 5, at step 502, a startup phase/coarse calibration of the transmit chains may be implemented. At 504, the method (500) may include determining a flag for performing receive chain calibration. At 506, if the base station has an option of the receive chain calibration at the start-up time, then the receive chain calibration may be executed. [086] At 508, if the flag is not set to 1, the method may wait for the operating phase to start the user data transmission. At 510, a value of a timer may be set to its initial value, which may be configurable. At 512, the timer may be started. In an embodiment, the operating phase/fine-tuned calibration may be implemented every time the timer expires. The operating phase/fine-tuned calibration may also be performed as requested by the higher layers or in an event of a significant change in the temperature, or a fault being identified in the reference chain. [087] Referring to FIG. 5, at 514, the method (500) may include determining if the timer has expired or if there is a need for calibration. The need for the calibration of the plurality of transmit chains may be based on, without limitation, an expiry of the timer, a request by the one or more higher layers, an event of a change in temperature, and a fault being identified in a given transmit chain of the plurality of transmit chains. If the timer has not expired and/or there is no need for calibration, the method (500) may include to continue to monitor the timer and/or the need for calibration. At 516, if the timer has expired or there is the need for calibration, the method (500) may include determining if the base station correspond to TDD or FDD mode. [088] At 518, if the base station corresponds to the TDD mode, the method (500) may include determining an arrival of a guard period of a special time slot. In an embodiment, the method (500) may include determining the arrival of a first guard period. At 520, the method (500) may perform the fine-tuned calibration of the transmit chains in the first guard period of the special time slot, if the first guard period of the special time slot has arrived. If the first guard period of the special time slot has not arrived, the method (500) continues to monitor the special time slot. [089] At 522, the method (500) may include determining the flag for performing receive chain calibration or transmit and receive chains re-calibration. If the flag is enabled, at 524, the method (500) may perform the fine-tuned calibration of the receive chains. [090] At 526, the method (500) may include determining whether re-calibration of the transmit or receive chains is performed, based on the determination of the flag, at 522. At 528, if re-calibration of the transmit or receive chains is not performed, the value of the timer may be incremented, and the method (500) may proceed to step 512. If the re-calibration of the transmit or receive chain is performed, the method (500) may proceed to step 510. [091] Referring to FIG. 5, at 530, if the base station corresponds to the FDD mode as determined at 516, the method (500) may include sending the request to one or more higher layers of the base station to allocate configurable number of vacated OFDM symbols for the calibration. At 532, the method (500) may include determining if the allocated OFDM symbols have arrived or not. [092] At 534, if the allocated OFDM symbols have arrived, the method (500) may perform the fine-tuned calibration of the transmit chains in the allocated OFDM symbols. If the allocated OFDM symbols are not arrived, the method (500) may continue to monitor the OFDM symbols. [093] At 536, the method (500) may include determining the flag for performing receive chain calibration or transmit and receive chains re-calibration. At 538, if the flag is enabled at 536, the method (500) may perform the fine-tuned calibration of the receive chains in the allocated OFDM symbols, and proceed to step 526.. If the flag is not enabled at 536, the method (500) may proceed to step 526... [094] In an embodiment, the calibration periodicity may be periodic and adaptive. In periodic calibration, the timer value may be constant, i.e., the calibration may be repeated after every one or two or any fixed number of TDD radio frames. In adaptive calibration, the timer value may not be fixed and may be updated adaptively. [095] Adaptive calibration may mitigate the issues of the periodic calibration. Since the temperature variation is expected to be higher during the initial time of the operating phase, the timer value may be incremented by smaller values. After certain cycles, the timer value may be incremented by larger values. For example, the Fibonacci series of 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610 (seconds) may be used as the timer value. [096] FIG. 6 illustrates a flow chart of an exemplary method (600) for coarse calibration of transmit chains in a base station, in accordance with an embodiment of the present disclosure. [097] With reference to FIG. 6, at 602, the method (600) may include setting all calibration coefficients to unity with zero phase and all delay values to zero in a calibrator (e.g., 210 of FIG. 2) for all transmit chains using a control signal (c1). [098] At 604, the method (600) may include setting a first multiplexer (MUXT) (e.g., 214) using a control signal (c2) to load the time-domain orthogonal sequences, for example, ZadoffChu sequences (ZT) as the test sequence. The ZadoffChu sequences may be generated offline and stored in a memory. The ZadoffChu sequences may be generated for different transmit chains, as shown in FIG. 7. In an embodiment, a ZadoffChu sequence generator may be implemented in a SoC (e.g., 202) to generate the ZadoffChu sequences in real-time. The ZadoffChu sequence may include two key parameters, namely, a length of the sequence , which may be an odd prime number, and a root index q = 0, 1, 2, …, - 1. With these two parameters, the ZadoffChu sequence may be defined as below: …………………….…………….(1) where . [099] The length of the ZadoffChu sequence may be a prime number and may be configurable. For example, the ZadoffChu sequence may be the largest prime number smaller than the FFT size. Zero padding may match the sequence length to the FFT size. The original ZadoffChu sequence may be used for the reference chain. For the other chains, the test sequence may be generated by a cyclic shift of the original ZadoffChu sequence, as shown in FIG. 7. The cyclic shift may be configurable. [0100] At 606, the ZadoffChu sequences may undergo DFE and DAC processing before feeding to the RF chains. A first summed signal (ysum) of all chains may be recovered or obtained from a feedback network (e.g., 222) and then processed through DFE and ORX-ADC blocks (e.g., 224). [0101] At 608, the method (600) may include estimating a first response (W) and a first timing delay (d) of each chain by cross-correlating the first summed signal (ysum) with the ZadoffChu sequences (Z) by a response and delay estimator (e.g., 226). [0102] The periodic cross-correlation of ysum with Z may be defined as below: ………….(2) where “*” is a complex conjugate, and “mod” is a modulus operator. [0103] At 610, the method (600) may include extracting the chain responses from the first response (W) and passing them through a OFDM demodulator (e.g., 228) to get the chain responses (hest). [0104] At 612, the method (600) may include informing a coefficient estimator (e.g., 230) to estimate the calibration coefficients (C) using a control signal (c4) for each transmit chain in order to mitigate the relative gain, phase, and timing differences with respect to the reference chain. [0105] The coefficients for each chain may be estimated from the chain responses (hest) to mitigate the gain and phase differences. The time delay differences may be mitigated using a time-shift property of a Fourier transform, i.e., a shift in time corresponds to a phase rotation in the frequency domain. The estimated calibration coefficients may be loaded into the calibrator (e.g., 210) using the control signal (c1). [0106] At 614, the method (600) may include setting a second multiplexer (MUXF) (e.g., 208) using a control signal (c3) to load the frequency-domain orthogonal sequences, for example, ZadoffChu sequences (ZF). The ZF may be generated by considering the FFT of the ZT. At 616, the calibration coefficients (C) may be applied on the ZadoffChu sequences (ZF) to obtain calibrated sequences. At 618, the calibrated sequences may be passed through the OFDM modulator (e.g., 212) and OFDM modulation may be performed to the calibrated sequences. The timing of the calibrated sequences may be adjusted using the delay adjuster (e.g., 234). [0107] At 620, the method (600) may include adjusting or controlling the first time delay in each transmit chain. At 622, the method (600) may include setting the MUXT (214) using a control signal (c2) to send the calibrated sequences on the transmit chains. At 624, a second summed signal (ysum) of all chains may be recovered or obtained from the feedback network (e.g., 222) and then processed through DFE and ORX-ADC blocks (224). At 626, a second response (W) and a second timing delay (d) of each chain may be estimated by cross-correlating the second summed signal (ysum) with the ZadoffChu sequences (Z) by the response and delay estimator (e.g., 226). [0108] At 628, the method (600) may include calculating Eg, Ep, and Ed for each chain with respect to the reference chain and comparing Eg, Ep, and Ed with Tg, Tp, and Td, respectively. At 630, the method (600) may include determining if Eg