Precoder prediction for scell using pcell csi

Abstract

Apparatuses and methods for a precoder prediction for a secondary cell (SCell) using a primary cell (PCell) channel state information (CSI) in a wireless communication system. A method of a base station (BS) in a wireless communication system includes: receiving an uplink (UL) sounding reference signal (SRS) on a primary cell (PCell); identifying, based on the UL SRS, spatial information associated with a frequency within a center frequency gap between a UL and a downlink (DL); identifying, based on the spatial information, one or more wideband (WB) precoders for at least one user equipment (UE) camping in a secondary cell (SCell); and transmitting, to the at least one UE, a signal based on the one or more WB precoders.

Description

PRECODER PREDICTION FOR SCELL USING PCELL CSI

[0001] The disclosure relates generally to wireless communication systems and, more specifically, the disclosure relates to precoder prediction for secondary cell (SCell) using a primary cell (PCell) channel state information (CSI) in a wireless communication system.

[0002] 5th generation (5G) or new radio (NR) mobile communications is recently gathering increased momentum with all the worldwide technical activities on the various candidate technologies from industry and academia. The candidate enablers for the 5G / NR mobile communications include massive antenna technologies, from cellular frequency bands up to high frequencies, to provide beamforming gain and support increased capacity, new waveform (e.g., a new radio access technology (RAT)) to flexibly accommodate various services / applications with different requirements, new multiple access schemes to support massive connections, and so on.

[0003] The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as related art with regard to the disclosure.

[0004] Aspects of the disclosure are to address at least the above-mentioned problems and / or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide a method for predicting network congestion in a wireless network system.

[0005] Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

[0006] The disclosure relates to a precoder prediction for SCell using a PCell CSI in a wireless communication system. According to an example embodiment of the disclosure, a base station (BS) in a wireless communication system is provided. The BS comprises memory storing instructions, and at least one processor communicatively coupled to the memory. The instructions, when executed by the at least one processor individually or collectively, cause the BS to: receive an uplink (UL) sounding reference signal (SRS) on a PCell, identify, based on the UL SRS, spatial information associated with a frequency within a center frequency gap between a UL and a downlink (DL), and identify, based on the spatial information, one or more wideband (WB) precoders for at least one user equipment (UE) camping in a SCell, wherein the transceiver is further configured to transmit, to the at least one UE, a signal based on the one or more WB precoders.

[0007] According to an example embodiment of the disclosure, a method of a BS in a wireless communication system is provided. The method comprises receiving a UL SRS on a PCell; identifying, based on the UL SRS, spatial information associated with a frequency within a center frequency gap between a UL and a DL; identifying, based on the spatial information, one or more WB precoders for at least one UE camping in a SCell; and transmitting, to the at least one UE, a signal based on the one or more WB precoders.

[0008] According to an example embodiment of the disclosure, a non-transitory computer-readable medium comprising program code, that when executed by at least one processor, causes a base station (BS) to: receive a UL SRS on a PCell; identify, based on the UL SRS, spatial information associated with a frequency within a center frequency gap between a UL and a DL; identify, based on the spatial information, one or more WB precoders for at least one UE camping in a SCell; and transmit, to the at least one UE, a signal based on the one or more WB precoders.

[0009] Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure.

[0010] The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0011] FIG. 1 illustrates an example of wireless network according to various embodiments of the disclosure;

[0012] FIG. 2 illustrates an example of gNB according to various embodiments of the disclosure;

[0013] FIG. 3 illustrates an example of UE according to various embodiments of the disclosure;

[0014] FIG. 4 and FIG. 5 illustrate examples of wireless transmit and receive paths according to the disclosure;

[0015] FIG. 6 illustrates an example of PCell and SCell channel frequency bands according to various embodiments of the disclosure;

[0016] FIG. 7 illustrates an example of SCell precoder computation from the PCell channel according to various embodiments of the disclosure;

[0017] FIG. 8 illustrates an example of throughput analysis according to various embodiments of the disclosure; and

[0018] FIG. 9 illustrates a flowchart of method for a precoder prediction for SCell using a PCell CSI in a wireless communication system according to various embodiments of the disclosure.

[0019] Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

[0020] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

[0021] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

[0022] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

[0023] It should be understood at the outset that although illustrative implementations of the embodiments of the disclosure are illustrated below, the disclosure may be implemented using any number of techniques, whether currently known or in existence. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, including the design and implementation illustrated and described herein, but may be modified within the scope of the appended claims along with their full scope of equivalents.

[0024] The term "some" as used herein is defined as "none, or one, or more than one, or all." Accordingly, the terms "none," "one," "more than one," "more than one, but not all" or "all" would all fall under the definition of "some." The term "some embodiments" may refer to no embodiments, to one embodiment or to several embodiments or to all embodiments. Accordingly, the term "some embodiments" is defined as meaning "no embodiment, or one embodiment, or more than one embodiment, or all embodiments."

[0025] The terminology and structure employed herein is for describing, teaching, and illuminating some embodiments and their specific features and elements and does not limit, restrict, or reduce the spirit and scope of the claims or their equivalents.

[0026] More specifically, any terms used herein such as but not limited to "includes," "comprises," "has," "consists," and grammatical variants thereof do NOT specify an exact limitation or restriction and certainly do NOT exclude the possible addition of one or more features or elements, unless otherwise stated, and furthermore must NOT be taken to exclude the possible removal of one or more of the listed features and elements, unless otherwise stated with the limiting language "MUST comprise" or "NEEDS TO include."

[0027] Whether or not a certain feature or element was limited to being used only once, either way, it may still be referred to as "one or more features" or "one or more elements" or "at least one feature" or "at least one element." Furthermore, the use of the terms "one or more" or "at least one" feature or element does NOT preclude there being none of that feature or element, unless otherwise specified by limiting language such as "there NEEDS to be one or more . . ." or "one or more element is REQUIRED."

[0028] Unless otherwise defined, all terms, and especially any technical and / or scientific terms, used herein may be taken to have the same meaning as commonly understood by one having ordinary skill in the art.

[0029] As used herein, each of such phrases as "A or B," "at least one of A and B," "at least one of A or B," "A, B, or C," "at least one of A, B, and C," and "at least one of A, B, or C," may include any one of, or all possible combinations of the items enumerated together in a corresponding one of the phrases. It is to be understood that if an element (e.g., a first element) is referred to, with or without the term "operatively" or "communicatively", as "coupled with," "coupled to," "connected with," or "connected to" another element (e.g., a second element), it means that the element may be coupled with the other element directly (e.g., wired), wirelessly, or via a third element.

[0030] It should be appreciated that the blocks in each flowchart and combinations of the flowcharts may be performed by one or more computer programs which include computer-executable instructions. The entirety of the one or more computer programs may be stored in a single memory device or the one or more computer programs may be divided with different portions stored in different multiple memory devices.

[0031] Any of the functions or operations described herein can be processed by one processor or a combination of processors. The one processor or the combination of processors is circuitry performing processing and includes circuitry like an application processor (AP, e.g., a central processing unit (CPU)), a communication processor (CP, e.g., a modem), a graphical processing unit (GPU), a neural processing unit (NPU) (e.g., an artificial intelligence (AI) chip), a wireless-fidelity (Wi-Fi) chip, a BluetoothTMchip, a global positioning system (GPS) chip, a near field communication (NFC) chip, connectivity chips, a sensor controller, a touch controller, a finger-print sensor controller, a display drive integrated circuit (IC), an audio CODEC chip, a universal serial bus (USB) controller, a camera controller, an image processing IC, a microprocessor unit (MPU), a system on chip (SoC), an IC, or the like.

[0032] FIGS. 1-9, discussed below, and the various embodiments used to describe the principles of the disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the disclosure may be implemented in any suitably arranged system or device.

[0033] To meet the demand for wireless data traffic having increased since deployment of 4G communication systems and to enable various vertical applications, 5G / NR communication systems have been developed and are being deployed. The 5G / NR communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 28 GHz or 60GHz bands, so as to accomplish higher data rates or in lower frequency bands, such as 6 GHz, to enable robust coverage and mobility support. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G / NR communication systems.

[0034] In addition, in 5G / NR communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancelation and the like.

[0035] The discussion of 5G systems and frequency bands associated therewith is for reference as certain embodiments of the disclosure may be implemented in 5G systems. However, the disclosure is not limited to 5G systems, or the frequency bands associated therewith, and embodiments of the disclosure may be utilized in connection with any frequency band. For example, aspects of the disclosure may also be applied to deployment of 5G communication systems, 6G or even later releases which may use terahertz (THz) bands.

[0036] The following documents are hereby incorporated by reference into the disclosure as if fully set forth herein: 3GPP TS 36.211 v16.4.0, "E-UTRA, Physical channels and modulation"; 3GPP TS 36.212 v16.4.0, "E-UTRA, Multiplexing and Channel coding"; 3GPP TS 36.213 v16.4.0, "E-UTRA, Physical Layer Procedures"; 3GPP TS 36.321 v16.3.0, "E-UTRA, Medium Access Control (MAC) protocol specification"; 3GPP TS 36.331 v16.3.0, "E-UTRA, Radio Resource Control (RRC) Protocol Specification"; 3GPP TS 38.211 v16.4.0, "NR, Physical channels and modulation"; 3GPP TS 38.212 v16.4.0, "NR, Multiplexing and Channel coding"; 3GPP TS 38.213 v16.4.0, "NR, Physical Layer Procedures for Control"; 3GPP TS 38.214 v16.4.0, "NR, Physical Layer Procedures for Data"; 3GPP TS 38.215 v16.4.0, "NR, Physical Layer Measurements"; 3GPP TS 38.321 v16.3.0, "NR, Medium Access Control (MAC) protocol specification"; and 3GPP TS 38.331 v16.3.1, "NR, Radio Resource Control (RRC) Protocol Specification."

[0037] FIGS. 1-3 below describe various embodiments implemented in wireless communications systems and with the use of orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) communication techniques. The descriptions of FIGS. 1-3 are not meant to imply physical or architectural limitations to the manner in which different embodiments may be implemented. Different embodiments of the disclosure may be implemented in any suitably arranged communications system.

[0038] FIG. 1 illustrates an example of wireless network according to embodiments of the disclosure. The embodiment of the wireless network shown in FIG. 1 is for illustration only. Other embodiments of the wireless network 100 may be used without departing from the scope of the disclosure.

[0039] Referring to FIG. 1, the wireless network may include a gNB 101 (e.g., base station, BS), a gNB 102, and a gNB 103. The gNB 101 may communicate with the gNB 102 and the gNB 103. The gNB 101 may also communicate with at least one network 130, such as the internet, a proprietary internet Protocol (IP) network, or other data network.

[0040] The gNB 102 may provide wireless broadband access to the network 130 for a first plurality of user equipments (UEs) within a coverage area 120 of the gNB 102. The first plurality of UEs may include a UE 111, which may be located in a small business; a UE 112, which may be located in an enterprise; a UE 113, which may be a WiFi hotspot; a UE 114, which may be located in a first residence; a UE 115, which may be located in a second residence; and a UE 116, which may be a mobile device, such as a cell phone, a wireless laptop, a wireless PDA, or the like. The gNB 103 may provide wireless broadband access to the network 130 for a second plurality of UEs within a coverage area 125 of the gNB 103. The second plurality of UEs may include the UE 115 and the UE 116. In an embodiment, one or more of the gNBs 101-103 may communicate with each other and with the UEs 111-116 using 5G / NR, long term evolution (LTE), long term evolution-advanced (LTE-A), WiMAX, WiFi, or other wireless communication techniques.

[0041] Depending on the network type, the term "base station" or "BS" can refer to any component (or collection of components) configured to provide wireless access to a network, such as transmit point (TP), transmit-receive point (TRP), an enhanced base station (eNodeB or eNB), a 5G / NR base station (gNB), a macrocell, a femtocell, a WiFi access point (AP), or other wirelessly enabled devices. Base stations may provide wireless access in accordance with one or more wireless communication protocols, e.g., 5G / NR 3rdgeneration partnership project (3GPP) NR, long term evolution (LTE), LTE advanced (LTE-A), high speed packet access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc. For the sake of convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. Also, depending on the network type, the term "user equipment" or "UE" can refer to any component such as "mobile station," "subscriber station," "remote terminal," "wireless terminal," "receive point," or "user device." For the sake of convenience, the terms "user equipment" and "UE" are used in this patent document to refer to remote wireless equipment that wirelessly accesses a BS, whether the UE is a mobile device (such as a mobile telephone or smartphone) or is normally considered as a stationary device (such as a desktop computer or vending machine).

[0042] Dotted lines show the approximate extents of the coverage areas 120 and 125, which are shown as approximately circular for the purposes of illustration and explanation only. It should be clearly understood that the coverage areas associated with gNBs, such as the coverage areas 120 and 125, may have other shapes, including irregular shapes, depending upon the configuration of the gNBs and variations in the radio environment associated with natural and man-made obstructions.

[0043] As described in more detail below, one or more of the UEs 111-116 may include circuitry, programming, or a combination thereof, for an operation for precoder prediction for SCell using a PCell CSI in a wireless communication system. In certain embodiments, and one or more of the gNBs 101-103 may include circuitry, programming, or a combination thereof, for precoder prediction for SCell using a PCell CSI in a wireless communication system.

[0044] Although FIG. 1 illustrates one example of a wireless network, various changes may be made to FIG. 1. For example, the wireless network may include any number of gNBs and any number of UEs in any suitable arrangement. Also, the gNB 101 may communicate directly with any number of UEs and provide those UEs with wireless broadband access to the network 130. Similarly, each gNB 102-103 may communicate directly with the network 130 and provide UEs with direct wireless broadband access to the network 130. Further, the gNBs 101, 102, and / or 103 may provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0045] FIG. 2 illustrates an example gNB 102 according to embodiments of the disclosure. The embodiment of the gNB 102 illustrated in FIG. 2 is for illustration only, and the gNBs 101 and 103 of FIG. 1 may have the same or similar configuration. However, gNBs may come in a wide variety of configurations, and FIG. 2 does not limit the scope of the disclosure to any particular implementation of a gNB.

[0046] Referring to FIG. 2, the gNB 102 may include multiple antennas 205a-205n, multiple transceivers 210a-210n, a controller / processor 225, memory 230, and a backhaul or network interface 235.

[0047] The transceivers 210a-210n may receive, from the antennas 205a-205n, incoming RF signals, such as signals transmitted by UEs in the network 100. The transceivers 210a-210n may down-convert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals may be processed by receive (RX) processing circuitry in the transceivers 210a-210n and / or controller / processor 225, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The controller / processor 225 may further process the baseband signals.

[0048] Transmit (TX) processing circuitry in the transceivers 210a-210n and / or controller / processor 225 may receive analog or digital data (such as voice data, web data, e-mail, or interactive video game data) from the controller / processor 225. The TX processing circuitry may encode, multiplexe, and / or digitize the outgoing baseband data to generate processed baseband or IF signals. The transceivers 210a-210n may up-convert the baseband or IF signals to RF signals that are transmitted via the antennas 205a-205n.

[0049] The controller / processor 225 may include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, the controller / processor 225 may control the reception of UL channel signals and the transmission of DL channel signals by the transceivers 210a-210n in accordance with well-known principles. The controller / processor 225 may support additional functions as well, such as more advanced wireless communication functions. For instance, the controller / processor 225 may support beam forming or directional routing operations in which outgoing / incoming signals from / to multiple antennas 205a-205n are weighted differently to effectively steer the outgoing signals in a desired direction. Any of a wide variety of other functions may be supported in the gNB 102 by the controller / processor 225.

[0050] The controller / processor 225 may also be capable of executing programs and other processes resident in the memory 230, such as processes for precoder prediction for SCell using a PCell CSI in a wireless communication system. The controller / processor 225 may move data into or out of the memory 230 as performed by an executing process.

[0051] The controller / processor 225 may also be coupled to the backhaul or network interface 235. The backhaul or network interface 235 may allow the gNB 102 to communicate with other devices or systems over a backhaul connection or over a network. The interface 235 may support communications over any suitable wired or wireless connection(s). For example, when the gNB 102 may be implemented as part of a cellular communication system (such as one supporting 5G / NR, LTE, or LTE-A), the interface 235 may allow the gNB 102 to communicate with other gNBs over a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the interface 235 may allow the gNB 102 to communicate over a wired or wireless local area network or over a wired or wireless connection to a larger network (such as the Internet). The interface 235 may include any suitable structure supporting communications over a wired or wireless connection, such as an Ethernet or transceiver. Furthermore, the controller / processor 225 may include various processing circuitry and / or multiple processors. For example, as used herein, including the claims, the term "processor" may include various processing circuitry, including at least one processor, wherein one or more of at least one processor, individually and / or collectively in a distributed manner, may be configured to perform various functions described herein. As used herein, when "a processor", "at least one processor", and "one or more processors" are described as being configured to perform numerous functions, these terms cover situations, for example and without limitation, in which one processor performs some of recited functions and another processor(s) performs other of recited functions, and also situations in which a single processor may perform all recited functions. Additionally, the at least one processor may include a combination of processors performing various of the recited / disclosed functions, e.g., in a distributed manner. At least one processor may execute program instructions to achieve or perform various functions.

[0052] The memory 230 is coupled to the controller / processor 225. Part of the memory 230 may include a RAM, and another part of the memory 230 may include a Flash memory or other ROM.

[0053] Although FIG. 2 illustrates one example of gNB 102, various changes may be made to FIG. 2. For example, the gNB 102 may include any number of each component shown in FIG. 2. Also, various components in FIG. 2 may be combined, further subdivided, or omitted and additional components may be added according to particular needs.

[0054] FIG. 3 illustrates an example UE 116 according to embodiments of the disclosure. The embodiment of the UE 116 illustrated in FIG. 3 is for illustration only, and the UEs 111-115 of FIG. 1 may have the same or similar configuration. However, UEs may come in a wide variety of configurations, and FIG. 3 does not limit the scope of the disclosure to any particular implementation of a UE.

[0055] Referring to FIG. 3, the UE　116 may include antenna(s) 305, a transceiver(s) 310, and a microphone 320. The UE　116 may also include a speaker 330, a processor 340, an input / output (I / O) interface (IF) 345, an input 350, a display 355, and memory 360. The memory 360 may include an operating system (OS) 361 and one or more applications 362.

[0056] The transceiver(s) 310 may receive from the antenna 305, an incoming RF signal transmitted by a gNB of the network 100. The transceiver(s) 310 may down-convert the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal may be processed by RX processing circuitry in the transceiver(s) 310 and / or processor 340, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry may send the processed baseband signal to the speaker 330 (such as for voice data) or is processed by the processor 340 (such as for web browsing data).

[0057] TX processing circuitry in the transceiver(s) 310 and / or processor 340 may receive analog or digital voice data from the microphone 320 or other outgoing baseband data (such as web data, e-mail, or interactive video game data) from the processor 340. The TX processing circuitry may encode, multiplexe, and / or digitize the outgoing baseband data to generate a processed baseband or IF signal. The transceiver(s) 310 may up-convert the baseband or IF signal to an RF signal that is transmitted via the antenna(s) 305.

[0058] The processor 340 may include one or more processors or other processing devices and execute the OS 361 stored in the memory 360 in order to control the overall operation of the UE 116. For example, the processor 340 may control the reception of DL channel signals and the transmission of UL channel signals by the transceiver(s) 310 in accordance with well-known principles. In an embodiment, the processor 340 may include at least one microprocessor or microcontroller.

[0059] The processor 340 may also be capable of executing other processes and programs resident in the memory 360, such as processes for supporting an operation of precoder prediction for SCell using a PCell CSI in a wireless communication system.

[0060] The processor 340 may move data into or out of the memory 360 as performed by an executing process. In an embodiment, the processor 340 may be configured to execute the applications 362 based on the OS 361 or in response to signals received from gNBs or an operator. The processor 340 may also be coupled to the I / O interface 345, which provides the UE 116 with the ability to connect to other devices, such as laptop computers and handheld computers. The I / O interface 345 may be the communication path between these accessories and the processor 340.

[0061] The processor 340 may also be coupled to the input 350 and the display 355 which includes for example, a touchscreen, keypad, etc., The operator of the UE 116 may use the input 350 to enter data into the UE 116. The display 355 may be a liquid crystal display, light emitting diode display, or other display capable of rendering text and / or at least limited graphics, such as from web sites. Furthermore, the processor 340 may include various processing circuitry and / or multiple processors. For example, as used herein, including the claims, the term "processor" may include various processing circuitry, including at least one processor, wherein one or more of at least one processor, individually and / or collectively in a distributed manner, may be configured to perform various functions described herein. As used herein, when "a processor", "at least one processor", and "one or more processors" are described as being configured to perform numerous functions, these terms cover situations, for example and without limitation, in which one processor performs some of recited functions and another processor(s) performs other of recited functions, and also situations in which a single processor may perform all recited functions. Additionally, the at least one processor may include a combination of processors performing various of the recited / disclosed functions, e.g., in a distributed manner. At least one processor may execute program instructions to achieve or perform various functions.

[0062] The memory 360 is coupled to the processor 340. Part of the memory 360 may include a random-access memory (RAM), and another part of the memory 360 may include a Flash memory or other read-only memory (ROM).

[0063] Although FIG. 3 illustrates one example of UE 116, various changes may be made to FIG. 3. For example, various components in FIG. 3 may be combined, further subdivided, or omitted and additional components may be added according to particular needs. As a particular example, the processor 340 may be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). In another example, the transceiver(s) 310 may include any number of transceivers and signal processing chains and may be connected to any number of antennas. Also, while FIG. 3 illustrates the UE 116 configured as a mobile telephone or smartphone, UEs may be configured to operate as other types of mobile or stationary devices.

[0064] FIG. 4 and FIG. 5 illustrate example wireless transmit and receive paths according to the disclosure. In the following description, a transmit path 400 may be described as being implemented in a gNB (such as the gNB 102), while a receive path 500 may be described as being implemented in a UE (such as a UE 116). However, it may be understood that the receive path 500 may be implemented in a gNB and that the transmit path 400 may be implemented in a UE. In various embodiments, the receive path 500 may be implemented in a first UE and the transmit path 400 may be implemented in a second UE. In an embodiment, the transmit path 400 may be configured to utilize a precoder prediction for SCell using a PCell CSI in a wireless communication system.

[0065] The transmit path 400 as illustrated in FIG. 4 may include a channel coding and modulation block 405, a serial-to-parallel (S-to-P) block 410, a size N inverse fast Fourier transform (IFFT) block 415, a parallel-to-serial (P-to-S) block 420, an add cyclic prefix block 425, and an up-converter (UC) 430. The receive path 500 as illustrated in FIG. 5 may include a down-converter (DC) 555, a remove cyclic prefix block 560, a serial-to-parallel (S-to-P) block 565, a size N fast Fourier transform (FFT) block 570, a parallel-to-serial (P-to-S) block 575, and a channel decoding and demodulation block 580.

[0066] As illustrated in FIG. 4, the channel coding and modulation block 405 may receive a set of information bits, apply coding (such as a low-density parity check (LDPC) coding), and modulate the input bits (such as with quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to generate a sequence of frequency-domain modulation symbols.

[0067] The serial-to-parallel block 410 may convert (such as de-multiplexes) the serial modulated symbols to parallel data in order to generate N parallel symbol streams, where N is the IFFT / FFT size used in the gNB 102 and the UE 116. The size N IFFT block 415 may perform an IFFT operation on the N parallel symbol streams to generate time-domain output signals. The parallel-to-serial block 420 may convert (such as multiplexe) the parallel time-domain output symbols from the size N IFFT block 415 in order to generate a serial time-domain signal. The add cyclic prefix block 425 may insert a cyclic prefix to the time-domain signal. The up-converter 430 may modulate (such as up-convert) the output of the add cyclic prefix block 425 to an RF frequency for transmission via a wireless channel. The signal may also be filtered at baseband before conversion to the RF frequency.

[0068] A transmitted RF signal from the gNB 102 may arrive at the UE 116 after passing through the wireless channel, and reverse operations to those at the gNB 102 are performed at the UE 116.

[0069] As illustrated in FIG. 5, the down converter 555 may down-convert the received signal to a baseband frequency, and the remove cyclic prefix block 560 may remove the cyclic prefix to generate a serial time-domain baseband signal. The serial-to-parallel block 565 may convert the time-domain baseband signal to parallel time domain signals. The size N FFT block 570 may perform an FFT algorithm to generate N parallel frequency-domain signals. The parallel-to-serial block 575 may convert the parallel frequency-domain signals to a sequence of modulated data symbols. The channel decoding and demodulation block 580 may demodulate and decode the modulated symbols to recover the original input data stream.

[0070] Each of the gNBs 101-103 may implement a transmit path 400 as illustrated in FIG. 4 that is analogous to transmitting in the downlink to UEs 111-116 and may implement a receive path 500 as illustrated in FIG. 5 that is analogous to receiving in the uplink from UEs 111-116. Similarly, each of UEs 111-116 may implement the transmit path 400 for transmitting in the uplink to the gNBs 101-103 and may implement the receive path 500 for receiving in the downlink from the gNBs 101-103.

[0071] Each of the components in FIG. 4 and FIG. 5 may be implemented using only hardware or using a combination of hardware and software / firmware. As a particular example, at least some of the components in FIG. 4 and FIG. 5 may be implemented in software, while other components may be implemented by configurable hardware or a mixture of software and configurable hardware. For instance, the FFT block 570 and the IFFT block 415 may be implemented as configurable software algorithms, where the value of size N may be modified according to the implementation.

[0072] Furthermore, although described as using FFT and IFFT, this is by way of illustration only and may not be construed to limit the scope of the disclosure. Other types of transforms, such as discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) functions, may be used. It may be appreciated that the value of the variable N may be any integer number (such as 1, 2, 3, 4, or the like) for DFT and IDFT functions, while the value of the variable N may be any integer number that is a power of two (such as 1, 2, 4, 8, 16, or the like) for FFT and IFFT functions.

[0073] Although FIG. 4 and FIG. 5 illustrate examples of wireless transmit and receive paths, various changes may be made to FIG. 4 and FIG. 5. For example, various components in FIG. 4 and FIG. 5 may be combined, further subdivided, or omitted and additional components may be added according to particular needs. Also, FIG. 4 and FIG. 5 are meant to illustrate examples of the types of transmit and receive paths that may be used in a wireless network. Any other suitable architecture may be used to support wireless communications in a wireless network.

[0074] In 5G NR systems, the data throughput may be augmented by using contiguous frequency bands, a SCell along with a PCell, to increase the total operating bandwidth. The precoders for the SCell may be either obtained as a PMI feedback from a UE or are computed at the base station from the channel state measured at its side. In an embodiment, the disclosed technology may include using the CSI obtained from the PCell's sounding reference signal (SRS) to predict the precoders for data transmission in the SCell.

[0075] In the disclosure, an embodiment may provide an electronic device and method on a calibration mechanism for (distributed) multi-input multi-output (MIMO) operations, more particularly, to the electronic device and method on a UE-assisted calibration mechanism in (distributed) MIMO of wireless networks.

[0076] In 5G NR systems, an SCell may be used along with the PCell to augment the data throughput. However, the precoders for the SCell may be obtained as a PMI feedback from the UE which is not very efficient. Obtaining the CSI at the base station using UL SRS on the SCell may also be expensive. Therefore, it is necessary to devise a technique to obtain the CSI for the SCell and use the CSI to compute the precoders.

[0077] In an embodiment, the UL SRS obtained from the PCell may be used to derive spatial information which are invariable to the frequency translation in a broader sense and use the spatial information to compute wideband (WB) precoders for the users in the SCell.

[0078] Although the disclosure may relate to 3GPP 5G NR communication systems, various embodiments may apply in general to UEs operating with other RATs and / or standards, such as different releases / generations of 3GPP standards (including beyond 5G, 6G, and so on), IEEE standards (such as 802.16 WiMAX and 802.11 Wi-Fi), and so on.

[0079] In an embodiment, a single user-MIMO (SU-MIMO) system where a base station with NTxantennas is intending to transmit data to UE with NRxantennas is provided. The received signal at the UE is given as: y=HPx+N where is the received signal, is the channel on ithRB, i∈[1, NRB] is between the base station and the UE, NRBis the number of the RBs, is the wideband precoders common across all RBs for the user, , r is the rank of the transmission and is the Gaussian noise with noise variance σ2.

[0080] The two different contiguous operating frequency bands may be used for channel transmission between the BS and the UE: the PCell and the SCell channels as shown in FIG. 6.

[0081] FIG. 6 illustrates an example of PCell and SCell channel frequency bands 600 according to embodiments of the disclosure. An embodiment of the PCell and SCell channel frequency bands 600 shown in FIG. 6 is for illustration only.

[0082] In an embodiment, the precoder for the SCell may be computed from the CSI received on the SCell. It may be assumed that the angle delay profile does not change over the different bands.

[0083] The precoder computation for sum capacity maximization given a channel CSI, H, is given as .

[0084] The optimal precoders P*may be computed to be the dominant Eigen vectors of the channel covariance matrix for large number of RBs. The dominant eigen vectors capture the spatial information as the frequency information is averaged out. The spatial information remains similar across the SCell and PCell. Therefore, the precoders determined from the PCell channel may be applied for transmission in the SCell.

[0085] In an embodiment, the rank of the transmission for the SCell may be determined from the channel quality indicator (CQI) feedback. The final precoders are the first r dominant eigen vectors from the eigen value decomposition of the channel covariance matrix as articulated above. The full process of determination of the SCell precoders have been represented in FIG. 7.

[0086] FIG. 7 illustrates an example of SCell precoder computation 700 from the PCell channel according to embodiments of the disclosure. An embodiment of the SCell precoder computation 700 shown in FIG. 7 is for illustration only.

[0087] As illustrated in FIG. 7, in operation 702, the channel capacity is identified on PCell channel. In operation 704, eigen values may be determined. In operation 706, dominant eigen vectors may be identified.

[0088] In an embodiment, a simple user classification may be provided based on the received reference signal received power (RSRP) of the UEs, to determine whether the use of wideband precoders from PCell CSI may be beneficial against the wideband PMI feedback obtained from the UE.

[0089] The received RSRP at the UEs may be a measure of the quality of the channel and it is also quantity reported by the UE to the base station. In an embodiment, this value (e.g., quality of channel reported to the base station) to determine the applicability of our wideband precoders. Basically, there is a threshold (=γRSRP) such that if the reported RSRP > γRSRP, the SCell precoders determined from the PCell channel may be used otherwise the wideband PMI precoders are used.

[0090] From the network side, when the RSRP feedback is not available from the UE, one indicator of the RSRP is the PCell SRS signa to noise ratio (SNR). The BS may select the UE that benefit from PCell CSI prediction from a certain SNR range. FIG. 3 illustrates that, in low SNR, the PCell SRS is not reliable, such that WB precoder will show loss, and, in very high SNR, the UE has very good DL SNR, such that the gain of using WB precoder to PMI is not significant.

[0091] FIG. 8 illustrates an example of throughput analysis 800 according to embodiments of the disclosure. An embodiment of the throughput analysis 800 shown in FIG. 8 is for illustration.

[0092] FIG. 9 illustrates a flowchart of method 900 for precoder prediction for SCell using a PCell CSI in a wireless communication system according to embodiments of the disclosure. The method 900 may be performed by a BS (e.g., 101-103 as illustrated in FIG. 1). An embodiment of the method 900 shown in FIG. 9 is for illustration only. One or more of the components illustrated in FIG. 9 may be implemented in specialized circuitry configured to perform the noted functions or one or more of the components may be implemented by one or more processors executing instructions to perform the noted functions.

[0093] As illustrated in FIG. 9, the method 900 begins at operation 902. In operation 902, a BS receives a UL SRS on a PCell.

[0094] In operation 904, the BS may identify, based on the UL SRS, spatial information associated with a frequency within a center frequency gap between a UL and a DL.

[0095] In operation 906, the BS may identify, based on the spatial information, one or more WB precoders for at least one UE camping in a SCell.

[0096] In operation 908, the BS may transmit, to the UE, a signal based on the one or more WB precoders.

[0097] In an embodiment, the BS may classify, based on an RSRP, the at least one UE to apply the one or more WB precoders.

[0098] In an embodiment, the BS may identify a function of an SNR of the UL SRS.

[0099] In an embodiment, the BS may determine, based on the function of the SNR of the UL SRS, whether to apply the one or more WB precoders for the at least one UE in accordance with a classification of the at least one UE.

[0100] In an embodiment, the BS may receive, from the at least one UE, information associated with an RSRP.

[0101] In an embodiment, the BS may identify a covariance expectation value based on the SRS of PCell to determine dominant eigen vectors of a channel covariance matrix for RBs.

[0102] In an embodiment, the BS may identify, based on the covariance matrix of the SRS, eigen vectors of the PCell.

[0103] In an embodiment, a number of the dominant eigen vectors to be used for the DL may be identified based on reported rank and a CQI for generating the one or more WB precoders for the SCell.

[0104] It will be appreciated that various embodiments of the disclosure according to the claims and description in the specification can be realized in the form of hardware, software or a combination of hardware and software.

[0105] Any such software may be stored in non-transitory computer readable storage media. The non-transitory computer readable storage media store one or more computer programs (software modules), the one or more computer programs include computer-executable instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform a method of the disclosure.

[0106] Any such software may be stored in the form of volatile or non-volatile storage, such as, for example, a storage device like read only memory (ROM), whether erasable or rewritable or not, or in the form of memory, such as, for example, random access memory (RAM), memory chips, device or integrated circuits or on an optically or magnetically readable medium, such as, for example, a compact disk (CD), digital versatile disc (DVD), magnetic disk or magnetic tape or the like. It will be appreciated that the storage devices and storage media are various embodiments of non-transitory machine-readable storage that are suitable for storing a computer program or computer programs comprising instructions that, when executed, implement various embodiments of the disclosure. Accordingly, various embodiments provide a program comprising code for implementing apparatus or a method as claimed in any one of the claims of this specification and a non-transitory machine-readable storage storing such a program.

[0107] While the disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.

Claims

1.A base station (BS) in a wireless communication system, the BS comprising:memory storing instructions; andat least one processor communicatively coupled to the memory,wherein the instructions, when executed by the at least one processor individually or collectively, cause the BS to:receive an uplink (UL) sounding reference signal (SRS) on a primary cell (PCell),identify, based on the UL SRS, spatial information associated with a frequency within a center frequency gap between a UL and a downlink (DL),identify, based on the spatial information, one or more wideband (WB) precoders for at least one user equipment (UE) camping in a secondary cell (SCell), andtransmit, to the at least one UE, a signal based on the one or more WB precoders.2.The BS of Claim 1, wherein the instructions, when executed by the at least one processor individually or collectively, cause the BS to classify, based on a reference signal received power (RSRP), the at least one UE to apply the one or more WB precoders.3.The BS of Claim 2, wherein the instructions, when executed by the at least one processor individually or collectively, cause the BS to:identify a function of a signal-to-noise ratio (SNR) of the UL SRS; anddetermine, based on the function of the SNR of the UL SRS, whether to apply the one or more WB precoders for the at least one UE in accordance with a classification of the at least one UE.4.The BS of Claim 1, wherein the instructions, when executed by the at least one processor individually or collectively, cause the BS to receive, from the at least one UE, information associated with a reference signal received power (RSRP).5.The BS of Claim 1, wherein the instructions, when executed by the at least one processor individually or collectively, cause the BS to identify a covariance expectation value based on the UL SRS to determine dominant eigen vectors of a channel covariance matrix for resource blocks (RBs).6.The BS of Claim 5, wherein the instructions, when executed by the at least one processor individually or collectively, cause the BS to identify, based on a covariance matrix of the SRS, eigen vectors of the PCell.7.The BS of Claim 5, wherein a number of the dominant eigen vectors to be used for the DL is identified based on reported rank and a channel quality indicator (CQI) for generating the one or more WB precoders for the SCell.8.A method of a base station (BS) in a wireless communication system, the method comprising:receiving an uplink (UL) sounding reference signal (SRS) on a primary cell (PCell);identifying, based on the UL SRS, spatial information associated with a frequency within a center frequency gap between a UL and a downlink (DL);identifying, based on the spatial information, one or more wideband (WB) precoders for at least one user equipment (UE) camping in a secondary cell (SCell); andtransmitting, to the at least one UE, a signal based on the one or more WB precoders.9.The method of Claim 8, further comprising classifying, based on a reference signal received power (RSRP), the at least one UE to apply the one or more WB precoders.10.The method of Claim 9, further comprising:identifying a function of a signal-to-noise ratio (SNR) of the UL SRS; anddetermining, based on the function of the SNR of the UL SRS, whether to apply the one or more WB precoders for the at least one UE in accordance with a classification of the at least one UE.11.The method of Claim 8, further comprising receiving, from the at least one UE, information associated with a reference signal received power (RSRP).12.The method of Claim 8, further comprising identifying a covariance expectation value based on the UL SRS to determine dominant eigen vectors of a channel covariance matrix for resource blocks (RBs).13.The method of Claim 12, further comprising identifying, based on a covariance matrix of the SRS, eigen vectors of the PCell.14.The method of Claim 12, wherein a number of the dominant eigen vectors to be used for the DL is identified based on reported rank and a channel quality indicator (CQI) for generating the one or more WB precoders for the SCell.15.A non-transitory computer-readable medium comprising program code, that when executed by at least one processor, causes a base station (BS) to:receive an uplink (UL) sounding reference signal (SRS) on a primary cell (PCell);identify, based on the UL SRS, spatial information associated with a frequency within a center frequency gap between a UL and a downlink (DL);identify, based on the spatial information, one or more wideband (WB) precoders for at least one user equipment (UE) camping in a secondary cell (SCell); andtransmit, to the at least one UE, a signal based on the one or more WB precoders.

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