Method and apparatus for performing multiple input multiple output (MIMO) data transmission in near-field

Abstract

The present disclosure relates to a 5G communication system or a 6G communication system for supporting higher data rates beyond a 4G communication system such as long term evolution (LTE). A method performed by a user equipment (UE) comprises receiving, from a base station, a plurality of configuration parameters associated with a Type-3 or Type-4 Channel State Information (CSI), generating, based on the received plurality of configuration parameters, an oversampled polar codebook comprising a plurality of polar codebook matrices and transmitting, to the base station, the Type-3 CSI feedback or the Type-4 CSI feedback. including CSI feedback along with at least one precoding matrix indicator configured to indicate at least one polar codebook matrix selected, among the plurality of polar codebook matrices, based on the CSI.

Description

METHOD AND APPARATUS FOR PERFORMING MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) DATA TRANSMISSION IN NEAR-FIELD

[0001] The present disclosure relates, in general, to the Channel State Information (CSI) feedback mechanism. Particularly, but not exclusively, the present disclosure relates to a method and system for performing Multiple Input Multiple Output (MIMO) data transmission.

[0002] Considering the development of wireless communication from generation to generation, the technologies have been developed mainly for services targeting humans, such as voice calls, multimedia services, and data services. Following the commercialization of 5G (5th-generation) communication systems, it is expected that the number of connected devices will exponentially grow. Increasingly, these will be connected to communication networks. Examples of connected things may include vehicles, robots, drones, home appliances, displays, smart sensors connected to various infrastructures, construction machines, and factory equipment. Mobile devices are expected to evolve in various form-factors, such as augmented reality glasses, virtual reality headsets, and hologram devices. In order to provide various services by connecting hundreds of billions of devices and things in the 6G (6th-generation) era, there have been ongoing efforts to develop improved 6G communication systems. For these reasons, 6G communication systems are referred to as beyond-5G systems.

[0003] 6G communication systems, which are expected to be commercialized around 2030, will have a peak data rate of tera (1,000 giga)-level bps and a radio latency less than 100μsec, and thus will be 50 times as fast as 5G communication systems and have the 1 / 10 radio latency thereof.

[0004] In order to accomplish such a high data rate and an ultra-low latency, it has been considered to implement 6G communication systems in a terahertz band (for example, 95GHz to 3THz bands). It is expected that, due to severer path loss and atmospheric absorption in the terahertz bands than those in mmWave bands introduced in 5G, technologies capable of securing the signal transmission distance (that is, coverage) will become more crucial. It is necessary to develop, as major technologies for securing the coverage, radio frequency (RF) elements, antennas, novel waveforms having a better coverage than orthogonal frequency division multiplexing (OFDM), beamforming and massive multiple input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antennas, and multiantenna transmission technologies such as large-scale antennas. In addition, there has been ongoing discussion on new technologies for improving the coverage of terahertz-band signals, such as metamaterial-based lenses and antennas, orbital angular momentum (OAM), and reconfigurable intelligent surface (RIS).

[0005] Moreover, in order to improve the spectral efficiency and the overall network performances, the following technologies have been developed for 6G communication systems: a full-duplex technology for enabling an uplink transmission and a downlink transmission to simultaneously use the same frequency resource at the same time; a network technology for utilizing satellites, high-altitude platform stations (HAPS), and the like in an integrated manner; an improved network structure for supporting mobile base stations and the like and enabling network operation optimization and automation and the like; a dynamic spectrum sharing technology via collision avoidance based on a prediction of spectrum usage; an use of artificial intelligence (AI) in wireless communication for improvement of overall network operation by utilizing AI from a designing phase for developing 6G and internalizing end-to-end AI support functions; and a next-generation distributed computing technology for overcoming the limit of UE computing ability through reachable super-high-performance communication and computing resources (such as mobile edge computing (MEC), clouds, and the like) over the network. In addition, through designing new protocols to be used in 6G communication systems, developing mechanisms for implementing a hardware-based security environment and safe use of data, and developing technologies for maintaining privacy, attempts to strengthen the connectivity between devices, optimize the network, promote softwarization of network entities, and increase the openness of wireless communications are continuing.

[0006] It is expected that research and development of 6G communication systems in hyper-connectivity, including person to machine (P2M) as well as machine to machine (M2M), will allow the next hyper-connected experience. Particularly, it is expected that services such as truly immersive extended reality (XR), high-fidelity mobile hologram, and digital replica could be provided through 6G communication systems. In addition, services such as remote surgery for security and reliability enhancement, industrial automation, and emergency response will be provided through the 6G communication system such that the technologies could be applied in various fields such as industry, medical care, automobiles, and home appliances.

[0007] Using a DFT codebook in near-field MIMO communication leads to significant energy leakage and reduced beamforming performance, ultimately impacting overall transmission efficiency is used in near-field communication.

[0008] The present disclosure relates to a 5G communication system or a 6G communication system for supporting higher data rates beyond a 4G communication system such as long term evolution (LTE). A method performed by a user equipment (UE) comprises receiving, from a base station, a plurality of configuration parameters associated with a Type-3 or Type-4 Channel State Information (CSI), generating, based on the received plurality of configuration parameters, an oversampled polar codebook comprising a plurality of polar codebook matrices and transmitting, to the base station, the Type-3 CSI feedback or the Type-4 CSI feedback. including CSI feedback along with at least one precoding matrix indicator configured to indicate at least one polar codebook matrix selected, among the plurality of polar codebook matrices, based on the CSI.

[0009] The embodiments of the disclosure itself, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings in which:

[0010] Figure 1 illustrates an angular spread in near-field, in accordance with an embodiment of the present disclosure;

[0011] Figure 2 illustrates Sparsity in a polar domain, in accordance with an embodiment of the present disclosure;

[0012] Figure 3 shows a sequence diagram indicating signalling procedures between the UE and BS for Type-3 CSI feedback, in accordance with an embodiment of the present disclosure;

[0013] Figure 4A shows a sequence diagram indicating signalling procedures for Type-4 CSI when RRC parameter subbandAmplitude = 0, in accordance with an embodiment of the present disclosure;

[0014] Figure 4B shows sequence diagram indicating signalling procedures for Type-4 CSI when RRC parameter subbandAmplitude = 1 in accordance with an embodiment of the present disclosure;

[0015] Figure 5 illustrates an environment for selection of users for location-division multiple access, in accordance with various embodiments of the present disclosure;

[0016] Figure 6A illustrates a flow chart indicating method for performing Multiple Input Multiple Output (MIMO) data transmission for Type 3 CSI feedback, in accordance with various embodiments of the present disclosure;

[0017] Figure 6B illustrates a flowchart of a method for performing Multiple Input Multiple Output (MIMO) data transmission for Type 4 CSI feedback, in accordance with various embodiments of the present disclosure;

[0018] Figure 6C illustrates a flowchart of a method for selection of users for location-division multiple access, in accordance with various embodiments of the present disclosure; and

[0019] Figure 7 is a block diagram of an exemplary computer system for implementing embodiments consistent with the present disclosure.

[0020] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

[0021] One or more shortcomings of the conventional systems are overcome by system and method as claimed and additional advantages are provided through the provision of system and method as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

[0022] In a non-limiting embodiment of the present disclosure, the method at user equipment for performing Multiple Input Multiple Output (MIMO) data transmission. The method comprises receiving, from a base station, a plurality of configuration parameters associated with a Type-3 Channel State Information (CSI). Further, the method discloses generating, based on the received plurality of configuration parameters, an oversampled polar codebook comprising a plurality of polar codebook matrices. Then, selecting based on CSI associated with a Channel State Information-Reference Signal (CSI-RS) received from the base station, at least one polar codebook matrix from the plurality of polar codebook matrices included in the oversampled polar codebook. Later, the method includes transmitting, to the base station, Type-3 CSI feedback including CSI feedback along with at least one precoding matrix indicator configured to indicate selection of the at least one polar codebook matrix. Finally, performing the MIMO data transmission with the base station based on the transmitted Type-3 CSI feedback.

[0023] In another non-limiting embodiment of the present disclosure, the plurality of configuration parameters associated with the Type 3 CSI comprises at least one of: an oversampling factor, maximum distance index (Pmax) for generating the oversampled polar codebook, parameter ( ) for correlation of a plurality of beams in the oversampled polar codebook, and a number of transmission layers.

[0024] In another non-limiting embodiment of the present disclosure, to generate the oversampled polar codebook, the method recites generating a polar codebook comprising a plurality of beamforming vectors. Further, the method includes interpolating the plurality of beamforming vectors by using oversampling factors to generate the oversampled polar codebook. The interpolation is performed by adjusting an angle and a distance parameter associated with the plurality of beamforming vectors.

[0025] In another non-limiting embodiment of the present disclosure, the method further recites receiving the CSI-RS from the base station. Based on the received CSI-RS, the method disclose estimating a channel based on the received CSI- RS to generate the CSI. Then, selecting at least one polar codebook matrix from a plurality of polar codebook matrices based on the generated CSI feedback.

[0026] In a non-limiting embodiment of the present disclosure, the method at user equipment for performing Multiple Input Multiple Output (MIMO) data transmission. The method comprises receiving, from a base station, a plurality of configuration parameters associated with Type-4 Channel State Information (CSI). Further, the method comprises generating, based on the received plurality of configuration parameters, an oversampled polar codebook comprising a plurality of polar codebook matrices. The method indicates selecting, based on CSI associated with a Channel State Information-Reference Signal (CSI-RS) received from the base station, at least one polar codebook matrix from the plurality of polar codebook matrices included in the oversampled polar codebook. Further, transmitting the Type-4 CSI feedback including CSI feedback along with at least one precoding matrix indicator configured to indicate selection of the at least one polar codebook matrix to the base station to perform the MIMO data transmission with the base station based on the transmitted Type-4 CSI feedback.

[0027] In a non-limiting embodiment of the present disclosure, the plurality of configuration parameters associated with Type-4 CSI comprises at least one of an oversampling factors, maximum distance index (Pmax) for generating the oversampled polar codebook, parameter ( ) for correlation of a plurality of beams in the oversampled polar codebook, a number of transmission layers and an amplitude index.

[0028] In a non-limiting embodiment of the present disclosure, the wherein the amplitude index include one of a sub-band amplitude index and a wide-band amplitude index.

[0029] In a non-limiting embodiment of the present disclosure, to generate the oversampled polar codebook, the method further recites generating a polar codebook comprising a plurality of beamforming vectors. The method comprises interpolating the plurality of beamforming vectors by using oversampling factors to generate the oversampled polar codebook. The interpolation is performed by adjusting an angle and a distance parameter associated with the plurality of beamforming vectors.

[0030] In a non-limiting embodiment of the present disclosure, the method recites receiving the CSI- RS from the base station and estimating a channel based on the received CSI-RS to generate the CSI feedback. Further, selecting the at least one polar codebook matrix from the plurality of polar codebook matrices based on the CSI feedback.

[0031] In a non-limiting embodiment of the present disclosure, the method for selection of users for location-division multiple access. The method discloses receiving a beam information in form of a beam from each UE of at least three UEs, wherein the beam information includes at least one of channel state information (CSI) feedback, and a precoding matrix indicator. Further, the method indicates determining beam correlation between the beams and calculating a distance and a position between UEs of the at least three UEs based on at least one of corresponding CSI feedback, corresponding precoding matrix indicator, and corresponding beam correlation. Finally, the method discloses selecting at least two UEs among the at least three UEs based on the calculated distance and the position.

[0032] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

[0033] In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0034] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and the scope of the disclosure.

[0035] The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a device or system or apparatus proceeded by "comprises ... a" does not, without more constraints, preclude the existence of other elements or additional elements in the device or system or apparatus.

[0036] In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings that form a part hereof, and which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

[0037] Generally, Multiple-input / multiple-out (MIMO) technology is an established wireless communications technique for sending and receiving multiple data signals simultaneously over the same radio channel. The MIMO techniques play a prominent role in Wi-Fi communications, as well as 3G, 4G, and 4G LTE networks. The MIMO technology is wireless technology that uses multiple transmitters and receivers to　transfer more data at same time.

[0038] An advanced form of this technology, known as an extremely large MIMO (XL-MIMO), is a key candidate that fulfils the promise of high spectral efficiency (bits / sec / Hz) requirements beyond 5G system. The XL-MIMO consists of thousands of antennas at the base station and is envisioned for the mid-frequency band (7-12 GHz), millimetre and terahertz band.

[0039] In case of Near-field MIMO communication, which is also referred to as a type of wireless communication using the MIMO technology, the transmitting and receiving antennas are positioned very close together, operating within the "near-field" region. Conventionally, CSI feedback in near-field MIMO communication is categorized into two types: Type-I and Type-II. the Type-I is a direct codebook format containing a small set of predefined codewords and the Type-II feedback is a construction-based feedback format where the channel state information is represented as a sum of multipath components. Both the Type 1 and the Type 2 conventionally use a Discrete Fourier Transform (DFT) codebook which consist of a set of pre-defined beamforming vectors for the Near-field MIMO communication. The beamforming vectors are specifically designed for near-field communication, where the wavefronts are not planar like in a far-field as the wave spreads and spherical waveforms are obtained when the DFT codebook is used in near-filed MIMO communication.

[0040] The DFT codebook often utilizing both angular and distance information to optimize transmission performance in the Near-field MIMO communication which indicates significant energy spreading across different angles and distances, leading to the need for specialized codebook designs that better capture the near-field channel properties. In other words, a UE may decode a channel state information reference signal (CSI-RS) received from a base station. The UE estimates a channel vector between the UE and the base station based on the CSI-RS. The UE selects a codebook index from a DFT codebook. The DFT codebook may be configured at the UE based on different inter-element distances and inter-panel distances in a uniform rectangular antenna panel array of a base station antenna. The UE encodes feedback that includes the codebook index for transmission to the base station. As the DFT codebook is used in near-field communication, it poorly represents the spherical wave propagation characteristics in close proximity to the transmitter, leading to significant energy leakage and reduced beamforming performance.

[0041] The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the application and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

[0042] In 5G cellular networks, beamforming is necessary for overcoming large channel pathloss when a user equipment (UE) tries to connect with a base station (BS) at different frequency bands. In an exemplary embodiment, when the UE tries to connect with the BS, the UE may be operated in millimeter wave (mmWave) bands but not limited thereto. To compensate for the smaller angular coverage due to the narrow analog beamwidth, beam sweeping may be employed to enable wider angular signal reception or transmission coverage for the UE. A beam codebook comprises a set of beams or codewords, where a codeword is a set of analog phase shift values, or a set of magnitude plus phase shift values, applied to the antenna elements, in order to form an analog beam. The codebooks are designed for different numbers of antenna elements, supporting a multitude of antenna configurations. The codebooks are designed symmetrically in order to mitigate the possible beam shift due to the large differences of wave lengths at different sub-bands of a wide band communication system.

[0043] In conventional implementations, Discrete Fourier Transform (DFT) codebooks are widely used for beamforming. When a UE receives a Channel State Information Reference Signal (CSI-RS) from a BS, it estimates the channel conditions and selects a codebook index from the DFT codebook. The DFT codebook is configured at the UE based on factors such as different inter-element distances and inter-panel distances in a uniform rectangular antenna panel array at a base station. The UE then encodes feedback that includes the selected codebook index and transmits the selected codebook index to the base station. However, in the near-field communication scenarios, the use of the DFT codebook present significant limitation as exhibits spherical wave characteristics due to the shorter transmission distances as indicated in fig 1. Unlike far-field communication, where wavefronts are approximately planar (fig 2), near-field communication exhibits spherical wave characteristics due to the shorter transmission distances. The DFT codebook does not accurately represent the spherical nature of wave propagation in near-field conditions. As a result, using a DFT codebook in near-field MIMO communication leads to significant energy leakage and reduced beamforming performance, ultimately impacting overall transmission efficiency is used in near-field communication.

[0044] Thus, the present disclosure may disclose a new polar codebook that may be used instead of DFT codebook, with the proposed structure, that holds the potential to increase CSI resolution significantly. The proposed scheme may be used in FR3 band along with FR2 (mmWave). The two types of CSI feedback is proposed based on single-user and multi-user. A Type 3 CSI feedback refers to　a specific method of transmitting Channel State Information (CSI) from a user equipment (UE) to the base station (BS), designed for scenarios with a high number of antennas at the BS which is a massive MIMO and often used in near-field environments, offering improved performance compared to traditional Type 1 and Type 2 feedback methods by providing more detailed channel information with optimized overhead management using the oversampled codebook. Particularly, the configuration parameters may be transmitted from the BS to the UE in both Type 3 and Type 4 CSI feedback. Based on the configuration parameters shared by the BS, the UE may select the codebook matrix from the plurality of codebook matrices and provide the type 3 and type 4 CSI feedback respectively to the BS. The Type-3, which has less overhead and low complexity can also be used by UEs with low-processing complexities. Similarly, Type 4 CSI feedback refers to　a specific method of transmitting channel state information (CSI) from a user equipment (UE) to the base station (BS), designed for multi-user MIMO (MU-MIMO) scenarios, particularly in near-field environments that involves combining multiple beams from an oversampled polar codebook using linear combining coefficients, providing a more accurate representation of the channel compared to simpler schemes while still maintaining manageable feedback overhead. The codebook may be oversampled by using two oversampling factors which may be angle and the distance, which can be further tuned to obtain higher resolution. Further, by considering the properties of Precoding Matrix Indicator in near-field, the present disclosure describes a method for location-division multiple access that allows the users in the near-field to be scheduled such that the spectral efficiency is increased.

[0045] The proposed feedback scheme when used for precoding in downlink data transmission, the gain observed in throughput was significantly higher compared with existing feedback schemes, such as Type-1 and Type-2 in 5G. For SU-MIMO, Type-3 feedback outperforms existing Type-1 CSI in 5G. As extreme-MIMO is supposedly multi-user centric (MU-MIMO), using proposed Type-4 CSI benefits from high throughput near to obtaining ideal CSI information. The overhead bits are similar to the existing feedback schemes and thus can be easily adapted into the standard for extremely large-MIMO. With the proposed selection of users for location-division multiple-access method, UEs are scheduled to achieve higher spectral efficiency.

[0046] Figure 3: shows signalling between the UE 303 and BS 301 for Type-3 CSI feedback, in accordance with an embodiment of the present disclosure. The UE 303 may comprise a processor, an I / O Interface, and a memory. Further, the BS 301 may comprise a processor, an I / O Interface, and a memory (not shown in fig 3) configured to perform Multiple Input Multiple Output (MIMO) data transmission.

[0047] Initially, the base station 301 may send a plurality of configuration parameters associated with a Type-3 Channel State Information. The plurality of configuration parameters associated with the Type 3 CSI comprises at least one of: an oversampling factor, maximum distance index (Pmax) for generating the oversampled polar codebook, parameter ( ) for correlation of a plurality of beams in the oversampled polar codebook, and a number of transmission layers.

[0048] In an embodiment, the oversampling factor is a parameter that determines the extent to which a signal is sampled beyond the minimum required Nyquist rate. The base station 301 may calculate the oversampling factors based on a plurality of factors such as signal bandwidth, signal quality, hardware associated with the base station 301 where the capabilities of the BS 301 hardware such as analog to digital converters, digital signal processors, and the like. In an embodiment, the maximum distance index may be defined as the representation of the maximum allowable distance for reliable communication with the UE 303. The BS 301 may use a combination of signal timing, signal strength, and other techniques to estimate maximum allowable distance. In an embodiment, the parameter ( ) may define the correlation among a plurality of beams in the oversampled polar codebook. The base station 301 may compute based on the spatial distribution of beams and the expected coherence of the channel. In an embodiment, the number of transmission layers refers to the number of spatial streams used for transmission.

[0049] Once, the UE 303 receives the plurality of configuration parameters associated with the Type-3 CSI, the UE 303 may generate an oversampled polar codebook comprising a plurality of polar codebook matrices. Specifically, when the base station 301 transmits the configuration parameters, the UE 303 may generate the polar codebook as illustrated in equation 1. The polar codebook may comprise the plurality of beamforming vectors.

[0050] (1)

[0051] where each element in the beam is,

[0052] Once, the polar codebook is generated, the UE 303 may perform Oversampling of the beamforming vectors in the polar codebook in both angle and distance. In an embodiment, the beamforming vectors may be oversampled in angle as shown below in equation 2.

[0053] (2)

[0054] In an embodiment, the beamforming vectors may be oversampled in phase as shown below in equation 3.

[0055] (3)

[0056] Once the beamforming vectors are oversampled, the UE 303 may perform interpolation of the plurality of beamforming vectors to generate the oversampled polar codebook as shown in equation 4. The process of interpolation may be defined as adjusting an angle and a distance parameter associated with the plurality of beamforming vectors.

[0057] (4)

[0058] where associated with equation (1) as described above.

[0059] In other words, the oversampled polar codebook may comprise a predefined set of codebook matrices that may be used by the UE 303 to quantize and report the channel conditions to the base station 301. Particularly, when the over sampled codebook is generated, the UE 303 may select one polar codebook matrix from the plurality of polar codebook matrices from the oversampled codebook based on the estimated channel and transmit Type-3 CSI feedback including CSI feedback along with at least one precoding matrix indicator configured to indicate selection of the at least one polar codebook matrix. The channel may be estimated when the BS 301 transmits the CSI-RS to the UE 303. When the UE 303, receives the CSI_RS, the UE 303 may estimate a channel based on the received CSI-RS to generate the CSI. Further, the UE 303 may select at least one polar codebook matrix from a plurality of polar codebook matrices based on the generated CSI and transmit Type-3 CSI feedback to the BS 301.

[0060] The CSI feedback may include, not limited to, Channel Quality Information (CQI), Precoding Matrix Indicator (PMI), CSI-RS Resource Indicator (CRI), synchronization signals (SS) and physical broadcast channel SS / PBCH Resource Block Indicator (SSBRI), Layer Indicator (LI), and Rank Indicator (RI).

[0061] In an embodiment, The CQI and PMI may be the parameters that UE 303 reports to the base station 301 to describe the channel conditions, allowing the base station 301 to optimize transmission by adjusting modulation and coding based on CQI and applying the appropriate precoding based on PMI.　The CQI represents the overall quality of the channel, indicating signal strength and how much data can be reliably transmitted. When the CQI is transmitted, the BS 301 uses CQI to choose the appropriate modulation and coding scheme for the transmission. The PMI represents the preferred precoding matrix to be used by the base station 301, which helps to focus the signal towards the UE 303 and improve signal quality in MIMO systems.

[0062] In an embodiment, the SS / PBCH Resource Block Indicator (SSBRI) may indicate the SS / PBCH resource block that the UE 303 identifies for initial access and beam selection. In an embodiment, the LI may specify the number of transmission layers that the UE 303 recommends for multiple-input multiple-output (MIMO) communication. In an embodiment, the RI may indicate the number of possible layers for the downlink transmission under specific channel conditions. The RI may also correspond to the maximum number of uncorrelated paths that the downlink transmission may use.

[0063] Further, when the UE 303 reports CRI and SSBRI to the BS 301, the report indicates which specific reference signals (CSI-RS for CRI and SS / PBCH blocks for SSBRI) the UE 303 may be using to measure the channel quality, allowing the base station 301 to optimize signal transmission based on the best available channel conditions.　Particularly, CSI parameters are the quantities related to the state of the channel. The UE 303 may report CSI parameters to the access network node (BS) 301 as feedback. Upon receiving the CSI parameters, the BS 301 may schedule downlink data transmissions such as modulation scheme, code rate, number of transmission layers, and MIMO precoding accordingly. The transmission of downlink data that is scheduled based on the CSI parameters.

[0064] Thus, when the BS 301 transmits the configuration parameters for Type 3 CSI feedback, i.e., for single-user MIMO, the base station 301 does not require high-resolution CSI information, and single dominant propagation path is sufficient for required throughput. Therefore, the present disclosure describes Type-3 CSI similar to Type-1 CSI, in which the user feedback single wideband beam from the polar codebook per layer of transmission as: , is the rank indicator (RI) for the user

[0065] The indices are fed back for layer

[0066] Therefore, the total overhead bits are

[0067] The present disclosure may focus on the base station 301 that may obtain high-resolution CSI feedback, which is used for XL-MIMO to increase spectral efficiency of the system. The proposed solutions describes a way to obtain the CSI information between UE 303 and BS 301. Based on the PMI obtained from the CSI, multiple UEs are scheduled based on maximum correlation between the PMI.

[0068] In the present disclosure, the oversampled polar codebook is presented, which has two oversampling factors. One for distance and another for angle. Therefore, BS 301 may flexibly choose the codebook for CSI feedback. In the proposed solution of the present disclosure, a CSI feedback mechanism and signal flow between BS 301 and UE 303 is presented for single-user MIMO use cases. This method significantly improves throughput compared with the conventional Type-1 CSI feedback. The performance improves further as the number of antennas grows larger at the BS 301 side.

[0069] Figure 4A:shows sequence diagram indicating signalling procedures for Type-4 CSI when RRC parametersubbandAmplitude = 0in accordance with an embodiment of the present disclosure.

[0070] Initially, the base station 301 may send plurality of configuration parameters associated with a Type-4 Channel State Information. The plurality of configuration parameters associated with the Type 4 CSI comprises at least one of an oversampling factor, Pmax, , amplitude index=0 and a transmission layers corresponding to data transmission between the base station 301 and the UE 303.

[0071] In an embodiment, definition and process of generation of oversampling factors, Pmax, , amplitude index=0 and a transmission layer may be same as explained in description of Fig. 3. For simplicity, the explanation definition and process of generation is avoided here. In an embodiment, the amplitude index may represent relative strength of different beams in a polar codebook. It may be used to adjust the power levels of beams.

[0072] Once, the UE 303 receives the plurality of configuration parameters associated with the Type-4 CSI, the UE 303 may generate an oversampled polar codebook comprising a plurality of polar codebook matrices. In other words, the codebook comprises a predefined set of pre-coded matrices that may be used by the UE 303 to quantize and report the channel conditions to the base station 301. Particularly, when the over sampled codebook is generated, the UE 303 may select one polar codebook matrix from the plurality of polar codebook matrices from the oversampled codebook based on the received CSI associated with a Channel State Information-Reference Signal (CSI-RS) received from the base station 301. Further, the UE 303 may transmit Type-4 CSI feedback including CSI feedback along with at least one precoding matrix indicator indicating selected at least one polar codebook matrix. Once, the base station 301 receives the Type-4 CSI feedback, the base station 301 may optimize its signal transmission based on the transmitted Type-4 CSI feedbackas shown in figure 4A.

[0073] Figure 4B:shows sequence diagram indicating signalling procedures for Type-4 CSI when RRC parametersubbandAmplitude = 1in accordance with an embodiment of the present disclosure.

[0074] Initially, the base station 301 may send plurality of configuration parameters associated with a Type-4 Channel State Information. The plurality of configuration parameters associated with the Type 4 CSI comprises at least one of an oversampling factor, Pmax, , amplitude index=1 and a transmission layers corresponding to data transmission between the base station 301 and the UE 303. The information associated with these parameters are similar to information present in the description of figure 4A.

[0075] Once, the UE 303 receives the plurality of configuration parameters associated with the Type-4 CSI, the UE 303 may generate an oversampled polar codebook comprising a plurality of polar codebook matrices. Particularly, when the over sampled codebook is generated, the UE 303 may select one polar codebook matrix from the plurality of polar codebook matrices from the oversampled codebook based on the estimated channel and the configuration parameters indicating the amplitude index and transmit Type-4 CSI feedback including CSI feedback along with at least one precoding matrix indicator indicating selected at least one polar codebook matrix. Once, the base station 301 receives the Type-4 CSI feedback, the base station 301 may optimize its signal transmission based on the transmitted Type-4 CSI feedbackas shown in figure 4B.

[0076] As explained above, the BS 301 may transmit particular amplitude index which may be at least one of amplitude index= 0 or amplitude index= 1. For instance, when the Type 4 CSI feedback for the subband, layer, and ifsubbandAmplitude=1 in CSI-config

[0077]

[0078] Where:

[0079] Similarly, if thesubbandAmplitude=0,only the wideband CSI is fed back as

[0080] is the wideband amplitude coefficient

[0081] is the subband amplitude coefficient

[0082] is the subband phase coefficient

[0083]

[0084] if thesubbandAmplitude=0,only the wideband CSI is fed back as

[0085]

[0086]

[0087]

[0088] Where:

[0089] is the wideband amplitude coefficient

[0090] is the wideband phase coefficient

[0091]

[0092]

[0093] The above-mentioned type of feedback may be indicated inside CSI config of RRC configuration message asCSI-type = 4.The proposed Type-4 CSI feedback scheme utilizes proposed oversampled polar codebook to enhance throughput significantly in MU-MIMO data transmission is shown in figure 4.

[0094] As, orthogonal beam pairs in the polar codebook is less, an indication of the maximum correlation between the beams in is given by the BS 301 in RRC configuration as max_corr. Which may take values as .

[0095] For feeding back the coefficients, which is based on the received amplitude index =0 or amplitude index=1, the UE 303 identifies a wideband strongest beam out of selected beams for layer as . Then, the coefficients are fed back in the uplink, such that

[0096] forsubbandAmplitude=1

[0097] forsubbandAmplitude=0

[0098] Further, Fig 5 indicates environment for selection of users for location-division multiple access, in accordance with the aspects of the present disclosure.

[0099] To schedule two users in the same angle but with different distance, the present disclosure describes minimizing the interference between the plurality of users. For instance, considers there are plurality of user in an environment which may be communicating with BS 301 at same angle and different distance. In such case, a beam information may be received in form of a beam from each UE 303 of at least three UEs. The beam information includes at least one channel state information (CSI) feedback, and a precoding matrix indicator. Further, correlation between the beams may be determined and then the distance and position between UEs of the at least three UEs may be calculated based on at least one of corresponding CSI feedback, corresponding precoding matrix indicator, and corresponding beam correlation. Finally, the at least two UEs among the at least three UEs may be selected based on the calculated distance and the position.

[0100] For instance, consider that one user is fixed at a distance ,to place the next user at distance ,the left-sided iso-correlation distance at should be equal to the right-sided iso-correlation distance at distance .Therefore, the distance may be found to be equal to

[0101]

[0102] where and

[0103] The , which depends on selected correlation threshold . The above-mentioned method may be continued in the same fashion to place more users in the same.

[0104] Based on the above-mentioned process, the sum-spectral efficiency achieved by placing the two users in the location selected by the selecting different correlation . The simulation setup is considered for total transmit antennas at the base station 301 is 257 in uniform-linear-array, and line-of-sight is considered. The one fixed user at 150m and then place the second user based on the . It may be observed that if the users are placed at a distance where the correlation between the PMI is higher, due to higher interference, the sum-spectral is lower. As the users are placed based on low correlation, the interference becomes lower. The present disclosure provides enhanced user experience i.e., the CSI feedback method improves significantly the experienced throughput for XL-MIMO systems both for single-user and multi-user cases. Specifically, for selecting of users for location-division multiple access, initially beam information may be received in form of a beam from each UE 303 of at least three UEs. The beam information includes at least one of channel state information (CSI) feedback, and a precoding matrix indicator. Further, the beam correlation between the beams may be determined and further a distance and a position between UEs of the at least three UEs is calculated based on at least one of corresponding CSI feedback, corresponding precoding matrix indicator, and corresponding beam correlation. Finally, the at least two UEs among the at least three UEs is selected based on the calculated distance and the position.

[0105] FIG 6A. shows a flow chart illustrating a method a user equipment for performing Multiple Input Multiple Output (MIMO) data transmission, in accordance with some embodiments of the present disclosure.

[0106] As illustrated in FIG.6A, the method 600A includes one or more blocks illustrating a method a user equipment for performing Multiple Input Multiple Output (MIMO) data transmission. The method 600A may be described in the general context of computer executable instructions. Generally, computer executable instructions may include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform functions or implement abstract data types.

[0107] The order in which the method 600 is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method 600A. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described herein. Furthermore, the method 600A may be implemented with any suitable hardware, software, firmware, or combination thereof.

[0108] At block 601, the method 600A discloses receiving from a base station 301, a plurality of configuration parameters associated with a Type-3 Channel State Information (CSI). The plurality of configuration parameters associated with the Type 3 CSI comprises at least one of: an oversampling factor, maximum distance index (Pmax) for generating the oversampled polar codebook, parameter ( ) for correlation of a plurality of beams in the oversampled polar codebook, and a number of transmission layers.

[0109] At block 603, the method 600A discloses generating, based on the received plurality of configuration parameters, an oversampled polar codebook comprising a plurality of polar codebook matrices.

[0110] At block 605, the method 600A discloses selecting, based on a CSI associated with a Channel State Information-Reference Signal (CSI-RS) received from the base station 301, at least one polar codebook matrix from the plurality of polar codebook matrices included in the oversampled polar codebook.

[0111] At block 607, the method 600A discloses transmitting to the base station 301, a Type-3 CSI feedback including CSI feedback along with at least one precoding matrix indicator configured to indicate selection of the at least one polar codebook matrix.

[0112] At block 609, the method 600A discloses performing the MIMO data transmission with the base station 301 based on the transmitted Type-3 CSI feedback.

[0113] FIG 6B.shows a flow chart illustrating a method a user equipment for performing Multiple Input Multiple Output (MIMO) data transmission, in accordance with some embodiments of the present disclosure.

[0114] As illustrated in FIG.6B, the method 600 includes one or more blocks illustrating a method a user equipment for performing Multiple Input Multiple Output (MIMO) data transmission. The method 600 may be described in the general context of computer executable instructions. Generally, computer executable instructions may include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform functions or implement abstract data types.

[0115] The order in which the method 600B is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method 600B. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described herein. Furthermore, the method 600B may be implemented with any suitable hardware, software, firmware, or combination thereof.

[0116] At block 601, the method 600B discloses receiving from a base station 301, a plurality of configuration parameters associated with a Type-4 Channel State Information (CSI). The plurality of configuration parameters associated with the Type 3 CSI comprises at least one of: an oversampling factor, maximum distance index (Pmax) for generating the oversampled polar codebook, parameter ( ) for correlation of a plurality of beams in the oversampled polar codebook, and a number of transmission layers.

[0117] At block 603, the method 600B discloses generating, based on the received plurality of configuration parameters, an oversampled polar codebook comprising a plurality of polar codebook matrices.

[0118] At block 605, the method 600B discloses selecting, based on a CSI associated with a Channel State Information-Reference Signal (CSI-RS) received from the base station 301, at least one polar codebook matrix from the plurality of polar codebook matrices included in the oversampled polar codebook.

[0119] At block 607, the method 600B discloses transmitting, to the base station 301, Type-4 CSI feedback including CSI feedback along with at least one precoding matrix indicator configured to indicate selection of the at least one polar codebook matrix.

[0120] At block 609, the method 600B discloses performing the MIMO data transmission with the base station 301 based on the transmitted Type-4 CSI feedback.

[0121] FIG 6C.shows a flow chart illustrating a method a user equipment for performing Multiple Input Multiple Output (MIMO) data transmission, in accordance with some embodiments of the present disclosure.

[0122] As illustrated in FIG.6C, the method 600C includes one or more blocks illustrating a method for selection of users for location-division multiple access. The method 600C may be described in the general context of computer executable instructions. Generally, computer executable instructions may include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform functions or implement abstract data types.

[0123] The order in which the method 600C is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method 600C. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described herein. Furthermore, the method 600C may be implemented with any suitable hardware, software, firmware, or combination thereof.

[0124] At block 601, the method 600C discloses receiving a beam information in form of a beam from each UE of at least three UEs, wherein the beam information includes at least one of channel state information (CSI) feedback, and a precoding matrix indicator.

[0125] At block 603, the method 600C discloses determining beam correlation between the beams.

[0126] At block 605, the method 600C discloses calculating a distance and a position between UEs of the at least three UEs based on at least one of corresponding CSI feedback, corresponding precoding matrix indicator, and corresponding beam correlation

[0127] At block 607, the method 600C discloses selecting at least two UEs among the at least three UEs based on the calculated distance and the position. Particularly, the calculated distance between the UEs of the at least three UEs is compared with a predefined threshold. Further, the method discloses identifying the distance between the UEs to be less than the predefined threshold to select at least two UEs among the at least three UEs based on the calculated distance and the position.

[0128] It may be noted here that the subject matter of some or all embodiments described with reference to Figs. 1-6 may be relevant for the methods and the same is not repeated for the sake of brevity.

[0129] FIG.7 is a block diagram of an exemplary computer system for implementing embodiments consistent with the present disclosure. In some embodiments, FIG.7 illustrates a block diagram of an exemplary computing system 700 for implementing embodiments consistent with the present application. In an embodiment, the computing system 700 may be a base station 301 or a UE 303. In some embodiments, the computing system 700 for performing Multiple Input Multiple Output (MIMO) data transmission. In an embodiment, the computing system 700 may be enabler client 301. The computer system 700 may include a central processing unit ("CPU" or "processor) 702. The processor 702 may include at least one data processor 702 for executing program components for executing user or system-generated business processes. The processor 702 may include specialized processing units such as integrated system (bus) controllers, memory management control units, floating point units, graphics processing units, digital signal processing units, etc.

[0130] The processor 702 may be disposed in communication with input devices 711 and output devices 712 via I / O interface 701. The I / O interface 701 may employ communication protocols / methods such as, without limitation, audio, analog, digital, stereo, IEEE-1394, serial bus, Universal Serial Bus (USB), infrared, PS / 2, BNC, coaxial, component, composite, Digital Visual Interface (DVI), high-definition multimedia interface (HDMI), Radio Frequency (RF) antennas, S-Video, Video Graphics Array (VGA), IEEE 802.n / b / g / n / x, Bluetooth, cellular (e.g., Code-Division Multiple Access (CDMA), High-Speed Packet Access (HSPA+), Global System For Mobile Communications (GSM), Long-Term Evolution (LTE), WiMax, or the like), etc. Using the I / O interface 701, computer system (UE) may communicate with input devices 711 and output devices 712. The input devices 711 and output devices 712 may be implemented as at least one transceiver.

[0131] In some embodiments, the processor 702 may be disposed in communication with a communication network 709 via a network interface 703. The network interface 703 may communicate with the communication network 709. The network interface 703 may employ connection protocols including, without limitation, direct connect, Ethernet (e.g., twisted pair 10 / 100 / 1000 Base T), Transmission Control Protocol / Internet Protocol (TCP / IP), token ring, IEEE 802.11a / b / g / n / x, etc. The communication network 709 may be implemented as one of the different types of networks, such as intranet or Local Area Network (LAN), Closed Area Network (CAN) and such within the vehicle. The communication network 709 may either be a dedicated network or a shared network, which represents an association of the different types of networks that use a variety of protocols, for example, Hypertext Transfer Protocol (HTTP), CAN Protocol, Transmission Control Protocol / Internet Protocol (TCP / IP), Wireless Application Protocol (WAP), etc., to communicate with each other. Further, the communication network 709 may include a variety of network devices, including routers, bridges, servers, computing devices, storage devices, etc. The one or more computing devices may include, but not limited to, a mobile phone, a tablet phone, a laptop and the like. In some embodiments, the processor 702 may be disposed in communication with a memory 705 (e.g., RAM, ROM, etc. not shown in FIG.7) via a storage interface 704. The storage interface 704 may connect to memory 705 including, without limitation, memory drives, removable disc drives, etc., employing connection protocols such as Serial Advanced Technology Attachment (SATA), Integrated Drive Electronics (IDE), IEEE-1394, Universal Serial Bus (USB), fibre channel, Small Computer Systems Interface (SCSI), etc. The memory drives may further include a drum, magnetic disc drive, magneto-optical drive, optical drive, Redundant Array of Independent Discs (RAID), solid-state memory devices, solid-state drives, etc. The memory 705 may store a collection of program or database components, including, without limitation, a user interface 706, an operating system 707, a web browser 708 etc. In some embodiments, the computer system 700 may store user / application data, such as the data, variables, records, etc. as described in this application. Such databases may be implemented as fault-tolerant, relational, scalable, secure databases such as Oracle or Sybase.

[0132] The operating system707may facilitate resource management and operation of the computer system700. Examples of operating systems include, without limitation, The User interface706may facilitate display, execution, interaction, manipulation, or operation of program components through textual or graphical facilities. For example, user interfaces may provide computer interaction interface elements on a display system operatively connected to the computer system700, such as cursors, icons, check boxes, menus, scrollers, windows, widgets, etc. Graphical User Interfaces (GUIs) may be employed.

[0133] In some embodiments, the computer system700may implement the web browser 708stored program components. The web browser708may be a hypertext viewing application. Secure web browsing may be provided using Secure Hypertext Transport Protocol (HTTPS), Secure Sockets Layer (SSL), Transport Layer Security (TLS), etc. Web browsers708may utilize facilities Application Programming Interfaces (APIs), etc. In some embodiments, the computer system700may implement a mail server stored program component. The mail server may be an Internet mail server such as Microsoft Exchange, or the like. The mail server may utilize facilities. The mail server may utilize communication protocols such as Internet Message Access Protocol (IMAP), Messaging Application Programming Interface (MAPI), Post Office Protocol (POP), Simple Mail Transfer Protocol (SMTP), or the like. In some embodiments, the computer system700may implement a mail client stored program component. The mail client may be a mail viewing application.

[0134] Furthermore, one or more computer-readable storage media may be utilized in implementing embodiments consistent with the present application. A computer-readable storage medium refers to any type of physical memory on which information or data readable by a processor702may be stored. Thus, a computer-readable storage medium may store instructions for execution by one or more processor 702, including instructions for causing the processor702to perform steps or stages consistent with the embodiments described herein. The term "computer-readable medium" should be understood to include tangible items and exclude carrier waves and transient signals, i.e., non-transitory. Examples include Random Access Memory (RAM), Read-Only Memory (ROM), volatile memory, non-volatile memory, hard drives, Compact Disc (CD) ROMs, Digital Video Disc (DVDs), flash drives, disks, and any other known physical storage media.

[0135] The terms "an embodiment", "embodiment", "embodiments", "the embodiment", "the embodiments", "one or more embodiments", "some embodiments", and "one embodiment" mean "one or more (but not all) embodiments of the application(s)" unless expressly specified otherwise.

[0136] The terms "including", "comprising", "having" and variations thereof mean "including but not limited to", unless expressly specified otherwise. The enumerated listing of items does not imply that any or all the items are mutually exclusive, unless expressly specified otherwise.

[0137] The terms "a", "an" and "the" mean "one or more", unless expressly specified otherwise. A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate the wide variety of possible embodiments of the application.

[0138] When a single device or article is described herein, it will be clear that more than one device / article (whether they cooperate) may be used in place of a single device / article. Similarly, where more than one device or article is described herein (whether they cooperate), it will be clear that a single device / article may be used in place of the more than one device or article, or a different number of devices / articles　may be used instead of the shown number of devices or programs. The functionality and / or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality / features. Thus, other embodiments of the application need not include the device itself.

[0139] Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the application be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the embodiments of the present application are intended to be illustrative, but not limiting, of the scope of the application, which is set forth in the following claims.

[0140] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

1.A method performed by a user equipment (UE) for performing multiple input multiple output (MIMO) data transmission, the method comprising:receiving, from a base station, a plurality of configuration parameters associated with a Type-3 channel state information (CSI);generating, based on the received plurality of configuration parameters, an oversampled polar codebook comprising a plurality of polar codebook matrices;selecting, based on CSI associated with a channel state information-reference signal (CSI-RS) received from the base station, at least one polar codebook matrix from the plurality of polar codebook matrices included in the oversampled polar codebook;transmitting, to the base station, Type-3 CSI feedback including CSI feedback along with at least one precoding matrix indicator configured to indicate selection of the at least one polar codebook matrix; andperforming the MIMO data transmission with the base station based on the transmitted Type-3 CSI feedback.2.The method of claim 1, wherein the plurality of configuration parameters associated with the Type 3 CSI comprises at least one of: an oversampling factor, maximum distance index (Pmax)for generating the oversampled polar codebook, parameter ( )for correlation of a plurality of beams in the oversampled polar codebook, and a number of transmission layers.3.The method of claim 2, wherein generating the oversampled polar codebook comprises:generating a polar codebook comprising a plurality of beamforming vectors; andinterpolating the plurality of beamforming vectors by using oversampling factors to generate the oversampled polar codebook, wherein the interpolation is performed by adjusting an angle and a distance parameter associated with the plurality of beamforming vectors.4.The method of claim 1, further comprising:receiving the CSI-RS from the base station;estimating a channel based on the received CSI-RS to generate the CSI feedback, andwherein selecting the at least one polar codebook matrix comprises:selecting the at least one polar codebook matrix from the plurality of polar codebook matrices based on the CSI feedback.5.A method performed by a user equipment (UE) for performing multiple input multiple output (MIMO) data transmission, the method comprising:receiving, from a base station, a plurality of configuration parameters associated with Type-4 channel state information (CSI);generating, based on the received plurality of configuration parameters, an oversampled polar codebook comprising a plurality of polar codebook matrices;selecting, based on CSI associated with a channel state information-reference signal (CSI-RS) received from the base station, at least one polar codebook matrix from the plurality of polar codebook matrices included in the oversampled polar codebook;transmitting, to the base station, the Type-4 CSI feedback including CSI feedback along with at least one precoding matrix indicator configured to indicate selection of the at least one polar codebook matrix; andperforming the MIMO data transmission with the base station based on the transmitted Type-4 CSI feedback.6.The method of claim 5, wherein the plurality of configuration parameters associated with Type-4 CSI comprises at least one of an oversampling factor, maximum distance index (Pmax) for generating the oversampled polar codebook, parameter ( ) for correlation of a plurality of beams in the oversampled polar codebook, a number of transmission layers and an amplitude index.7.The method of claim 6, wherein the amplitude index include one of a sub-band amplitude index and a wide-band amplitude index.8.The method of claim 6, wherein generating the oversampled polar codebook comprises:generating a polar codebook comprising a plurality of beamforming vectors; andinterpolating the plurality of beamforming vectors by using oversampling factors to generate the oversampled polar codebook, wherein the interpolation is performed by adjusting an angle and a distance parameter associated with the plurality of beamforming vectors.9.The method of claim 5, further comprising:receiving the CSI-RS from the base station; andestimating a channel based on the received CSI-RS to generate the CSI feedback,wherein selecting the at least one polar codebook matrix comprises:selecting the at least one polar codebook matrix from the plurality of polar codebook matrices based on the CSI feedback.10.A user equipment (UE) for performing multiple input multiple output (MIMO) data transmission, the UE comprises:a transceiver;at least one processor communicatively coupled to the transceiver; andat least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the UE to:receive a plurality of configuration parameters associated with a Type-3 channel state information (CSI) from a base station,generate, based on the received plurality of configuration parameters, an oversampled polar codebook comprising a plurality of polar codebook matrices,select, based on CSI associated with a channel state information-reference signal (CSI-RS) received from the base station, at least one polar codebook matrix from the plurality of polar codebook matrices included in the oversampled polar codebook,transmit, to the base station, a Type-3 CSI feedback including CSI feedback along with at least one precoding matrix indicator configured to indicate selection of the at least one polar codebook matrix, andperform the MIMO data transmission with the base station based on the transmitted Type-3 CSI feedback.11.The UE of claim 10, wherein the plurality of configuration parameters associated with the Type 3 CSI comprises at least one of: an oversampling factor, maximum distance index (Pmax)for generating the oversampled polar codebook, parameter ( ) for correlation of a plurality of beams in the oversampled polar codebook, and a number of transmission layers.12.The UE of claim 11 wherein the at least one memory stores further instructions executable by the at least one processor individually or in any combination to cause the UE to:generate a polar codebook comprising a plurality of beamforming vectors, andinterpolate the plurality of beamforming vectors by using oversampling factor to generate the oversampled polar codebook, wherein the interpolation is performed by adjusting an angle and a distance parameters associated with the plurality of beamforming vectors.13.A user equipment (UE) for performing multiple input multiple output (MIMO) data transmission, the UE comprises:a transceiver;at least one processor communicatively coupled to the transceiver; andat least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the UE to:receive, from a base station, a plurality of configuration parameters associated with Type-4 channel state information (CSI);generate, based on the received plurality of configuration parameters, an oversampled polar codebook comprising plurality of polar codebook matrices;select, based on CSI associated with a channel state information-reference signal (CSI-RS) received from the base station, at least one polar codebook matrix from the plurality of polar codebook matrices included in the oversampled polar codebook;transmit, to the base station, a Type-4 CSI feedback including CSI feedback along with at least one precoding matrix indicator configured to indicate selection of at least one polar codebook matrix; andperform the MIMO data transmission with the base station based on the transmitted Type-4 CSI feedback.14.The UE of claim 13, wherein the plurality of configuration parameters associated with Type-4 CSI comprises at least one of an oversampling factor, maximum distance index (Pmax)for generating the oversampled polar codebook, parameter ( )for correlation of a plurality of beams in the oversampled polar codebook, an amplitude index and a transmission layers.15.The UE of claim 13, wherein the at least one memory stores further instructions executable by the at least one processor individually or in any combination to cause the UE to:generate a polar codebook comprising a plurality of beamforming vectors, andinterpolate the plurality of beamforming vectors by using oversampling factors to generate the oversampled polar codebook, wherein the interpolation is performed by adjusting an angle and a distance parameters associated with the plurality of beamforming vectors.

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