Method and apparatus for bit compression of uplink fronthaul data

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method and apparatus for bit compression of uplink fronthaul data in a wireless communication system are provided. In one embodiment, a method of a UE includes identifying uplink forward data to reduce data loading on an uplink forward link, where the uplink forward link is between an RU and a DU; processing the uplink fronthaul data to obtain a set of representative values for a compression operation; selecting at least one coding parameter for the compression operation based on the set of representative values; and transmitting the uplink fronthaul data compressed based on the compression operation to the DU.

Description

Technical Field

[0001] This disclosure generally relates to wireless communication systems, and more specifically, to methods and apparatus for bit compression of uplink fronthaul data in wireless communication systems. Background Technology

[0002] 5G mobile communication technology defines a wide frequency band, enabling high transmission rates and new services. It can be implemented not only in "sub-6 GHz" bands such as 3.5 GHz, but also in "above 6 GHz" bands, including 28 GHz and 39 GHz, known as mmWave. Furthermore, to achieve transmission rates 50 times faster than 5G and ultra-low latency one-tenth that of 5G, 6G mobile communication technology (referred to as "super 5G systems") in terahertz (THz) bands (e.g., the 95 GHz to 3 THz band) has been considered.

[0003] In the early stages of 5G mobile communication technology development, in order to support services and meet performance requirements related to enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC), standardization has been carried out on the following: beamforming and massive MIMO for mitigating radio wave path loss and increasing radio wave transmission distance in mmWave units; parameter sets supporting dynamic operation for efficient utilization of mmWave resources and time slot formats (e.g., operating multiple subcarrier spacings); initial access technologies for supporting multi-beam transmission and broadband; definition and operation of bandwidth portions (BWP); new channel coding methods such as low-density parity-check (LDPC) codes for large-volume data transmission and polarity codes for highly reliable transmission of control information; L2 preprocessing; and network slicing for providing dedicated networks for specific services.

[0004] Currently, given the services that will be supported by 5G mobile communication technology, there are ongoing discussions regarding improvements and performance enhancements to the initial 5G mobile communication technology, and there is already physical layer standardization for technologies such as: V2X (vehicle-to-everything) for assisting autonomous vehicle driving determination by using information sent by the vehicle about its location and status and for enhancing user convenience; NR-U (New Radio Unlicensed) for system operation in unlicensed frequency bands in compliance with various regulatory requirements; NR UE power saving; non-terrestrial networks (NTNs) for providing coverage in areas where communication with terrestrial networks is unavailable; and positioning.

[0005] In addition, there is ongoing standardization of air interface architectures / protocols for technologies such as: Industrial Internet of Things (IIoT) to support new services through interoperability and convergence with other industries; IAB (Integrated Access and Backhaul) for nodes to provide network service area extension by supporting radio backhaul and access links in an integrated manner; mobility enhancements including conditional handover and DAPS (Dual Active Stack) handover; and two-step random access (2-step RACH for NR) to simplify the random access process. There is also ongoing standardization of 5G baseline architectures (e.g., service-based architectures or service-based interfaces) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and system architectures / services for Mobile Edge Computing (MEC) based on UE location reception services.

[0006] With the commercialization of 5G mobile communication systems, an exponential increase in connected devices will be added to the communication network. Therefore, enhanced functionality and performance of 5G mobile communication systems, as well as the integrated operation of connected devices, are expected to be necessary. To this end, new research related to extended reality (XR) is planned to effectively support AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality), etc., by leveraging artificial intelligence (AI) and machine learning (ML), AI service support, metaverse service support, and drone communication to improve 5G performance and reduce complexity.

[0007] Furthermore, this development of 5G mobile communication systems will serve as a foundation for: not only developing new waveforms for providing terahertz band coverage for 6G mobile communication technologies, multi-antenna transmission technologies (such as full-dimensional MIMO (FD-MIMO), array antennas, and massive MIMO), metamaterial-based lenses and antennas for improving terahertz band signal coverage, high-dimensional spatial multiplexing technologies using OAM (orbital angular momentum), and RIS (reconfigurable smart surfaces), but also developing full-duplex technologies to improve the frequency efficiency of 6G mobile communication technologies and enhance system networks, AI-based communication technologies for system optimization by leveraging satellites and AI (artificial intelligence) from the design phase and internalizing end-to-end AI support capabilities, and next-generation distributed computing technologies for providing services with complexity exceeding the limits of UE operational capabilities by utilizing ultra-high-performance communication and computing resources. Summary of the Invention

[0008] Solution to the problem

[0009] This disclosure relates to wireless communication systems, and more specifically, to methods and apparatus for bit compression of uplink fronthaul data in wireless communication systems.

[0010] In one embodiment, a radio unit (RU) is provided in a wireless communication system. The RU includes a processor configured to identify uplink fronthaul data to reduce data load on the uplink fronthaul link, wherein the uplink fronthaul link is between the RU and a distributed unit (DU); process the uplink fronthaul data to obtain a representative set of values ​​for compression operations; and select at least one encoding parameter for the compression operations based on the representative set of values. The RU also includes a transceiver operatively coupled to the processor, configured to transmit uplink fronthaul data compressed based on the compression operations to the DU.

[0011] Beneficial effects of the invention

[0012] According to this disclosure, a method and apparatus for bit compression of uplink fronthaul data in a wireless communication system are provided. Attached Figure Description

[0013] To gain a more complete understanding of this disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals denote like parts:

[0014] Figure 1 Examples of wireless networks according to various embodiments of this disclosure;

[0015] Figure 2 Examples illustrating various embodiments of the gNB according to this disclosure;

[0016] Figure 3 Examples of UEs illustrating various embodiments of this disclosure;

[0017] Figure 4 and Figure 5 Examples illustrating wireless transmission and reception paths according to various embodiments of this disclosure;

[0018] Figure 6 Examples illustrating antenna structures according to various embodiments of this disclosure;

[0019] Figure 7 Examples of DUs connected to multiple RUs via fiber-optic fronthaul links according to various embodiments of this disclosure;

[0020] Figure 8 Examples illustrating uplink processing chains according to various embodiments of this disclosure;

[0021] Figure 9 Examples of fronthaul compression blocks integrated into an uplink processing chain at a RU according to various embodiments of the present disclosure are shown;

[0022] Figure 10Examples illustrating the sequence of steps in the prepass compression at the RU according to various embodiments of this disclosure;

[0023] Figure 11 Examples illustrating the encoding process according to various embodiments of this disclosure;

[0024] Figure 12 Examples illustrating the decoding process according to various embodiments of this disclosure;

[0025] Figure 13 Another example illustrating the decoding process according to various embodiments of this disclosure;

[0026] Figure 14 Examples illustrating the sequence of steps in the prepass compression at the RU according to various embodiments of this disclosure;

[0027] Figure 15 Examples illustrating RU architectures and algorithms according to various embodiments of this disclosure;

[0028] Figure 16 Examples illustrating compressed bit widths according to various embodiments of this disclosure;

[0029] Figure 17 Examples illustrating various embodiments of the H.264 architecture according to this disclosure;

[0030] Figure 18 Examples illustrating color mapping according to various embodiments of this disclosure;

[0031] Figure 19 Examples illustrating the NMSE compression ratio trade-offs without preprocessing according to various embodiments of this disclosure;

[0032] Figure 20 Examples illustrating NMSE compression ratio tradeoffs with channel inversion and channel matching according to various embodiments of this disclosure; and

[0033] Figure 21 A flowchart illustrating a bit compression RU method for uplink fronthaul data according to various embodiments of the present disclosure.

[0034] Figure 22 This is a block diagram of the internal configuration of a base station according to an embodiment.

[0035] Figure 23 This is a block diagram illustrating the internal structure of a terminal according to an embodiment of the present disclosure.

[0036] Best mode

[0037] This disclosure relates to wireless communication systems, and more specifically, to bit compression of uplink fronthaul data in wireless communication systems.

[0038] In one embodiment, a radio unit (RU) is provided in a wireless communication system. The RU includes a processor configured to identify uplink fronthaul data to reduce data load on the uplink fronthaul link, wherein the uplink fronthaul link is between the RU and a distributed unit (DU); process the uplink fronthaul data to obtain a representative set of values ​​for compression operations; and select at least one encoding parameter for the compression operations based on the representative set of values. The RU also includes a transceiver operatively coupled to the processor, configured to transmit uplink fronthaul data compressed based on the compression operations to the DU.

[0039] In another embodiment, a method for an RU is provided. The method includes: identifying uplink fronthaul data to reduce data load on an uplink fronthaul link, wherein the uplink fronthaul link is between the RU and the DU; processing the uplink fronthaul data to obtain a representative set of values ​​for a compression operation; selecting at least one encoding parameter for the compression operation based on the representative set of values; and sending uplink fronthaul data compressed based on the compression operation to the DU.

[0040] In another embodiment, a non-transitory computer-readable medium including program code is provided. When executed by at least one processor, the non-transitory computer-readable medium causes an electronic device to: identify uplink fronthaul data to reduce data load on the uplink fronthaul link, wherein the uplink fronthaul link is between the RU and DU; process the uplink fronthaul data to obtain a representative set of values ​​for a compression operation; select at least one encoding parameter for the compression operation based on the representative set of values; and send uplink fronthaul data compressed based on the compression operation to the DU.

[0041] Other technical features will be apparent to those skilled in the art from the following figures, description and claims. Detailed Implementation

[0042] Before proceeding with the following detailed description, it may be advantageous to define certain words and phrases used throughout this patent document. The term “coupled” and its derivatives refer to any direct or indirect communication between two or more elements, regardless of whether these elements are physically in contact with each other. The terms “transmit,” “receive,” and “communicate,” and their derivatives, cover both direct and indirect communication. The terms “include” and “comprise,” and their derivatives, mean including but not limited to. The term “or” is inclusive, meaning and / or. The phrase “associated with,” and its derivatives, mean including, being included in, interconnected with, containing, being contained within, connected to or connected with, coupled to or coupled with, able to communicate with, cooperate with, interleave, juxtapose, proximate, bound to or bound with, having, possessing the properties of, related to, etc. The term “controller” means any device, system, or part thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller may be centralized or distributed, either local or remote. When used with a list of items, the phrase "at least one" means that different combinations of one or more items can be listed, and it may be necessary to list only one item. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0043] Furthermore, the various functions described below can be implemented or supported by one or more computer programs, each computer program being formed by computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, instances, associated data, or portions thereof suitable for implementation in appropriate computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, optical disc (CD), digital video disc (DVD), or any other type of storage. "Non-transitory" computer-readable media does not include wired, wireless, optical, or other communication links that transmit transient electrical or other signals. Non-transitory computer-readable media includes media that can permanently store data and media that can store data and subsequently overwrite it, such as rewritable optical discs or erasable memory devices.

[0044] Definitions for certain other words and phrases are provided throughout this patent document. Those skilled in the art will understand that, in many, if not most, instances, these definitions apply to the prior and future use of the defined words and phrases.

[0045] Fifth-generation (5G), or new radio (NR) mobile communications, is gaining increasing momentum recently amid global technological activity surrounding a wide range of candidate technologies from industry and academia. Candidate enablers for 5G / NR mobile communications include massive MIMO technologies from high to high frequencies in traditional cellular bands to provide beamforming gain and support increased capacity; new waveforms (e.g., new radio access technologies (RATs)) to flexibly adapt to various services / applications with different needs; and new multiple access schemes to support massive connectivity, among others.

[0046] The following discussion Figures 1 to 23 The various embodiments used to describe the principles disclosed in this patent document are merely exemplary and should not be construed in any way as limiting the scope of this disclosure. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged system or device.

[0047] To meet the increased demand for wireless data traffic since the deployment of 4G communication systems and to enable various vertical applications, 5G / NR communication systems have been developed and are currently being deployed. 5G / NR communication systems are considered to be implemented in higher frequency (mmWave) bands (e.g., 28 GHz or 60 GHz) for higher data rates, or in lower frequency bands (e.g., 6 GHz) for robust coverage and mobility support. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies are discussed in 5G / NR communication systems.

[0048] In addition, in 5G / NR communication systems, development is underway to improve system networks based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, cooperative multipoint (CoMP), and receiver interference cancellation.

[0049] The discussion of 5G systems and their associated frequency bands is for reference only, as some embodiments of this disclosure can be implemented in 5G systems. However, this disclosure is not limited to 5G systems or their associated frequency bands, and embodiments of this disclosure can be used in conjunction with any frequency band. For example, aspects of this disclosure can also be applied to deployments of 5G communication systems, 6G using terahertz (THz) bands, or even higher versions.

[0050] The following Figures 1 to 3 This describes various embodiments of communication technologies implemented in wireless communication systems using Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA). Figures 1 to 3 The description does not imply a physical or architectural limitation on how different embodiments may be implemented. Different embodiments of this disclosure can be implemented in any suitably arranged communication system.

[0051] Figure 1 This document describes example wireless networks according to various embodiments of the present disclosure. Figure 1 The embodiments of the wireless network shown are for illustrative purposes only. Other embodiments of the wireless network 100 may be used without departing from the scope of this disclosure.

[0052] like Figure 1 As shown, the wireless network includes gNB 101 (e.g., a base station BS), gNB 102, and gNB 103. gNB 101 communicates with gNB 102 and gNB 103. gNB 101 also communicates with at least one network 130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network.

[0053] gNB 102 provides wireless broadband access to network 130 to a first plurality of user equipments (UEs) within its coverage area 120. The first plurality of UEs includes: UE 111, which may be located in a small business; UE 112, which may be located in an enterprise; UE 113, which may be a WiFi hotspot; UE 114, which may be located in a first residence; UE 115, which may be located in a second residence; and UE 116, which may be a mobile device, such as a cellular phone, wireless laptop, wireless PDA, etc. gNB 103 provides wireless broadband access to network 130 to a second plurality of UEs within its coverage area 125. The second plurality of UEs includes UE 115 and UE 116. In some embodiments, one or more of gNBs 101 to 103 may communicate with each other and with UEs 111 to 116 using 5G / NR, Long Term Evolution (LTE), LTE-A Advanced, WiMAX, WiFi, or other wireless communication technologies.

[0054] Depending on the network type, the term "base station" or "BS" can refer to any component (or set of components) configured to provide wireless access to a network, such as a transmitting point (TP), a transmitting-receiving point (TRP), an enhanced base station (eNodeB or eNB), a 5G / NR base station (gNB), a macro cell, a femtocell, a WiFi access point (AP), or other wirelessly enabled device. A base station can provide wireless access according to one or more wireless communication protocols, such as 5G / NR 3rd Generation 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 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. Furthermore, depending on the network type, the term "user equipment" or "UE" can refer to any component, such as a "mobile station," "subscriber station," "remote terminal," "wireless terminal," "receiving point," or "user device." For convenience, the terms “user equipment” and “UE” are used in this patent document to refer to a remote wireless device for wireless access to a BS, whether the UE is a mobile device (such as a mobile phone or smartphone) or is generally considered to be a fixed device (such as a desktop computer or vending machine).

[0055] The dashed lines indicate the approximate extent of coverage areas 120 and 125, which are shown as approximately circular for illustrative and explanatory purposes only. It should be clearly understood that, depending on the configuration of the gNB and variations in the radio environment associated with natural and man-made obstacles, the coverage areas associated with the gNB (such as coverage areas 120 and 125) may have other shapes, including irregular shapes.

[0056] As described in more detail below, one or more of gNBs 101 to 103 include circuitry, procedures, or combinations thereof to support bit compression of uplink fronthaul data in a wireless communication system.

[0057] although Figure 1 This is an example illustrating a wireless network, but it can be used to illustrate... Figure 1Various modifications can be made. For example, the wireless network can include any number of gNBs and any number of UEs in any suitable arrangement. Furthermore, gNB 101 can communicate directly with any number of UEs and provide these UEs with wireless broadband access to network 130. Similarly, each gNB 102 and 103 can communicate directly with network 130 and provide the UEs with direct wireless broadband access to network 130. Additionally, gNBs 101, 102, and / or 103 can provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0058] Figure 2 Example gNB 102 illustrates various embodiments of this disclosure. Figure 2 The illustrated embodiment of gNB 102 is for illustrative purposes only, and Figure 1 gNBs 101 and 103 can have the same or similar configurations. However, gNBs come in a wide variety of configurations, and Figure 2 This disclosure is not intended to limit the scope to any particular implementation of gNB.

[0059] like Figure 2 As shown, gNB 102 includes multiple antennas 205a to 205n, multiple transceivers 210a to 210n, a controller / processor 225, a memory 230, and a backhaul or network interface 235.

[0060] Transceivers 210a to 210n receive incoming RF signals, such as signals transmitted by a UE in network 100, from antennas 205a to 205n. Transceivers 210a to 210n down-convert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are processed by receive (RX) processing circuitry in transceivers 210a to 210n and / or controller / processor 225, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. Controller / processor 225 may further process the baseband signals.

[0061] Transmit (TX) processing circuitry in transceivers 210a to 210n and / or controller / processor 225 receives analog or digital data (such as voice data, web data, email, or interactive video game data) from controller / processor 225. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. Transceivers 210a to 210n up-convert the baseband or IF signal into an RF signal transmitted via antennas 205a to 205n.

[0062] 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, based on well-known principles, control the reception of UL channel signals and the transmission of DL channel signals via transceivers 210a to 210n. The controller / processor 225 may also support additional functions, such as more advanced wireless communication capabilities. For example, the controller / processor 225 may support beamforming or directional routing operations, wherein outgoing / incoming signals from / to multiple antennas 205a to 205n are weighted differently to effectively direct outgoing signals in a desired direction. The controller / processor 225 may support any of a variety of other functions within the gNB 102.

[0063] The controller / processor 225 is also capable of executing programs and other processes residing in the memory 230, such as bit compression processes to support uplink fronthaul data in a wireless communication system. The controller / processor 225 can move data into or out of the memory 230 as needed for the execution process.

[0064] The controller / processor 225 is also coupled to a backhaul or network interface 235. The backhaul or network interface 235 allows the gNB 102 to communicate with other devices or systems via a backhaul connection or network. Interface 235 can support communication via any suitable wired or wireless connection(s). For example, when the gNB 102 is implemented as part of a wireless communication system (such as a wireless communication system supporting 5G / NR, LTE, or LTE-A), interface 235 can allow the gNB 102 to communicate with other gNBs via a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, interface 235 can allow the gNB 102 to communicate with a larger network (such as the Internet) via a wired or wireless local area network or via a wired or wireless connection. Interface 235 includes any suitable architecture supporting communication via a wired or wireless connection, such as Ethernet or a transceiver.

[0065] The memory 230 is coupled to the controller / processor 225. A portion of the memory 230 may include RAM, while another portion of the memory 230 may include flash memory or other ROM.

[0066] although Figure 2 This is an example illustrating gNB 102, but it can be used for... Figure 2 Various changes can be made. For example, gNB 102 can include... Figure 2 Each component, in any number as shown. Furthermore, Figure 2 The various components can be combined, further subdivided, or omitted, and additional components can be added as needed.

[0067] Figure 3 Example UE 116 is described according to various embodiments of the present disclosure. Figure 3 The illustrated embodiment of UE 116 is for illustrative purposes only, and Figure 1 UEs 111 to 115 can have the same or similar configurations. However, UEs have a wide variety of configurations, and Figure 3 This disclosure does not limit its scope to any particular implementation of the UE.

[0068] like Figure 3 As shown, UE 116 includes antenna(s) 305, transceivers(s) 310, and microphone(s) 320. UE 116 also includes speaker(s) 330, processor(s) 340, input / output (I / O) interface(IF) 345, input(s) 350, display(s) 355, and memory(s) 360. Memory(s) 360 includes operating system(OS) 361 and one or more applications(s) 362.

[0069] Multiple transceivers 310 receive incoming RF signals transmitted by a gNB of network 100 from antenna 305. The multiple transceivers 310 down-convert the incoming RF signals to generate intermediate frequency (IF) or baseband signals. The IF or baseband signals are processed by RX processing circuitry in the multiple transceivers 310 and / or processor 340, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The RX processing circuitry transmits the processed baseband signals (e.g., for voice data) to speaker 330 or is processed by processor 340 (e.g., for web browsing data).

[0070] The TX processing circuitry in (multiple) transceivers 310 and / or processor 340 receives analog or digital voice data from microphone 320, or other outgoing baseband data (such as web data, email, or interactive video game data) from processor 340. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The (multiple) transceivers 310 up-convert the baseband or IF signal into an RF signal transmitted via (multiple) antennas 305.

[0071] Processor 340 may include one or more processors or other processing devices and execute OS 361 stored in memory 360 to control the overall operation of UE 116. For example, processor 340 may control the reception of DL channel signals and the transmission of UL channel signals via transceivers(s) 310, based on well-known principles. In some embodiments, processor 340 includes at least one microprocessor or microcontroller.

[0072] Processor 340 can move data into or out of memory 360 as needed during execution. In some embodiments, processor 340 is configured to execute application 362 based on OS 361 or in response to signals received from gNB or operator. Processor 340 is also coupled to I / O interface 345, which provides UE 116 with the ability to connect to other devices, such as laptop computers and handheld computers. I / O interface 345 is the communication path between these accessories and processor 340.

[0073] The processor 340 is also coupled to the input 350 and the display 355m, which include, for example, a touchscreen, a keyboard, etc. The operator of the UE 116 can use the input 350 to input data into the UE 116. The display 355m can be a liquid crystal display, a light-emitting diode display, or other display capable of displaying text and / or at least limited graphics (such as from a website).

[0074] The memory 360 is coupled to the processor 340. A portion of the memory 360 may include random access memory (RAM), and another portion of the memory 360 may include flash memory or other read-only memory (ROM).

[0075] although Figure 3 This is an example illustrating UE 116, but it can be used for... Figure 3 Make various changes. For example, Figure 3 The various components can be combined, further subdivided, or omitted, and additional components can be added as needed. As a specific example, processor 340 can 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, transceivers 310 can include any number of transceivers and signal processing chains and can be connected to any number of antennas. Furthermore, although... Figure 3 The UE 116 is configured as a mobile phone or smartphone, but the UE can be configured to operate as other types of mobile or fixed devices.

[0076] Figure 4 and Figure 5 Example wireless transmit and receive paths according to various embodiments of this disclosure are described. In the following description, transmit path 400 may be described as being implemented in a gNB (such as gNB 102), and receive path 500 may be described as being implemented in a UE (such as UE 116). However, it will be understood that receive path 500 may be implemented in a gNB, and transmit path 400 may be implemented in a UE. In some embodiments, receive path 500 is configured to support bit compression of uplink fronthaul data in a wireless communication system.

[0077] like Figure 4 The transmission path 400 described includes a channel coding and modulation block 405, a serial-to-parallel (S-to-P) block 410, an inverse fast Fourier transform (IFFT) block of size N 415, a parallel-to-serial (P-to-S) block 420, a cyclic prefix addition block 425, and an up-converter (UC) 430. For example... Figure 5 The receiver path 500 described herein includes a downconverter (DC) 555, a cyclic prefix removal block 560, a serial-to-parallel (S-to-P) block 565, a fast Fourier transform (FFT) block of size N, a parallel-to-serial (P-to-S) block 575, and a channel decoding and demodulation block 580.

[0078] like Figure 4 As explained, the channel coding and modulation block 405 receive the set of information bits, apply coding (such as low-density parity-check (LDPC) coding) and modulate the input bits (such as using quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to generate a frequency domain modulated symbol sequence.

[0079] Serial-to-parallel block 410 converts (e.g., demultiplexes) serial modulation symbols into parallel data to generate N parallel symbol streams, where N is the IFFT / FFT size used in gNB 102 and UE 116. IFFT block 415 of size N performs IFFT operations on the N parallel symbol streams to generate a time-domain output signal. Parallel-to-serial block 420 converts (e.g., multiplexes) the parallel time-domain output symbols from IFFT block 415 of size N to generate a serial time-domain signal. Cyclic prefix addition block 425 inserts a cyclic prefix into the time-domain signal. Upconverter 430 modulates (e.g., upconverts) the output of cyclic prefix addition block 425 to an RF frequency for transmission via a wireless channel. The signal may also be filtered in baseband before conversion to the RF frequency.

[0080] The RF signal transmitted from gNB 102 reaches UE 116 after passing through the wireless channel, and UE 116 performs the opposite operation to that at gNB 102.

[0081] like Figure 5 As described, downconverter 555 downconverts the received signal to the baseband frequency, and cyclic prefix removal block 560 removes the cyclic prefix to generate a serial time-domain baseband signal. Serial-to-parallel block 565 converts the time-domain baseband signal into a parallel time-domain signal. FFT block 570 of size N performs the FFT algorithm to generate N parallel frequency-domain signals. Parallel-to-serial block 575 converts the parallel frequency-domain signals into a sequence of modulated data symbols. Channel decoding and demodulation block 580 demodulates and decodes the modulated symbols to recover the original input data stream.

[0082] Each of BS 101 to 103 can perform actions similar to those sent to UE 111 to 116 in the downlink. Figure 4 The transmission path 400 described herein can achieve a similar effect to receiving data from UE 111 to 116 in the uplink. Figure 5 The receive path 500 is described in the document. Similarly, each of UEs 111 to 116 can implement a transmit path 400 for transmitting to gNBs 101 to 103 in the uplink and a receive path 500 for receiving from gNBs 101 to 103 in the downlink.

[0083] Figure 4 and Figure 5 Each of the components can be implemented using only hardware or a combination of hardware and software / firmware. As a specific example, Figure 4 and Figure 5 At least some of the components can be implemented in software, while others can be implemented in configurable hardware or a hybrid of software and configurable hardware. For example, FFT block 570 and IFFT block 415 can be implemented as configurable software algorithms, where the value of size N can be modified according to the implementation.

[0084] Furthermore, although described as using FFT and IFFT, this is merely illustrative and should not be construed as limiting the scope of this disclosure. Other types of transforms, such as the Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions, can be used. It will be understood that for the DFT and IDFT functions, the value of variable N can be any integer (such as 1, 2, 3, 4, etc.), while for the FFT and IFFT functions, the value of variable N can be any integer that is a power of 2 (such as 1, 2, 4, 8, 16, etc.).

[0085] although Figure 4 and Figure 5 This provides an example illustrating the wireless transmit and receive path, but it is possible to... Figure 4 and Figure 5 Make various changes. For example, Figure 4 and Figure 5 The various components can be combined, further subdivided, or omitted, and additional components can be added as needed. Furthermore, Figure 4 and Figure 5 This section illustrates examples of the types of transmit and receive paths that can be used in a wireless network. Any other suitable architecture can be used to support wireless communication in a wireless network.

[0086] The unit on a cell used for DL ​​(Deep Path) or UL (Ultra Path) signaling is called a time slot, and it may include one or more symbols. A bandwidth (BW) unit is called a resource block (RB). An RB comprises multiple subcarriers (SCs). For example, a time slot may have a duration of 1 millisecond, and an RB may have a bandwidth of 180 kHz and include 12 SCs, with an interval of 15 kHz between SCs. A time slot may be a full DL time slot, a full UL time slot, or a hybrid time slot similar to a special subframe in a Time Division Duplex (TDD) system.

[0087] DL signals include data signals conveying information content, control signals conveying DL control information (DCI), and reference signals (RS), also known as pilot signals. The gNB transmits data information or DCI via the corresponding Physical DL Shared Channel (PDSCH) or Physical DL Control Channel (PDCCH). PDSCH or PDCCH can be transmitted on a variable number of time slot symbols, each including one time slot symbol. The spatial settings for PDCCH reception can be indicated to the UE based on the configuration of the TCI state value for the CORESET of the UE's PDCCH reception. The spatial settings for PDSCH reception can also be indicated to the UE based on higher-level configuration or based on the indication of the TCI state value for the DCI format used to schedule PDSCH reception. The gNB can configure the UE to receive signals on cells within the DL bandwidth portion (BWP) of the cell's DL BW.

[0088] The gNB transmits one or more of various RSs, including Channel State Information RS (CSI-RS) and Demodulation RS (DMRS). CSI-RS is primarily used by the UE to perform measurements and provide Channel State Information (CSI) to the gNB. For channel measurements, Non-Zero Power CSI-RS (NZP CSI-RS) resources are used. For Interference Measurement Reporting (IMR), CSI Interference Measurement (CSI-IM) resources associated with Zero Power CSI-RS (ZP CSI-RS) configuration are used. The CSI process includes both NZP CSI-RS and CSI-IM resources. The UE can determine CSI-RS transmission parameters via DL control signaling or higher-level signaling, such as Radio Resource Control (RRC) signaling from the gNB. The transmission instance of CSI-RS can be indicated by DL control signaling or configured by higher-level signaling. DMRS is transmitted only in the BW of the corresponding PDCCH or PDSCH, and the UE can use DMRS to demodulate data or control information.

[0089] UL signals also include data signals conveying information content, control signals conveying UL control information (UCI), DMRS associated with data or UCI demodulation, probe RS (SRS) enabling the gNB to perform UL channel measurements, and random access (RA) preamble enabling the UE to perform random access. The UE transmits data information or UCI via the corresponding Physical UL Shared Channel (PUSCH) or Physical UL Control Channel (PUCCH). PUSCH or PUCCH can be transmitted on a variable number of time slot symbols, including one time slot symbol. The gNB can configure the UE to transmit signals on cells within the UL BWP of the cell UL BW.

[0090] UCI includes a Hybrid Automatic Repeat Request Acknowledgment (HARQ-ACK) message indicating whether a data transport block (TB) in the PDSCH has been correctly or incorrectly detected, a scheduling request (SR) indicating whether the UE has data in its buffer, and a CSI report enabling the gNB to select appropriate parameters for PDSCH or PDCCH transmissions to the UE. The HARQ-ACK message can be configured to have a smaller granularity than per TB and can be per data code block (CB) or per group of data CBs, where a data TB comprises multiple data CBs.

[0091] The CSI report from the UE may include: a Channel Quality Indicator (CQI) informing the gNB of the maximum modulation and coding scheme (MCS) used by the UE to detect the data TB at a predetermined block error rate (BLER) (such as 10% BLER); a Precoding Matrix Indicator (PMI) informing the gNB how to combine signals from multiple transmitter antennas according to MIMO transmission principles; and a Rank Indicator (RI) indicating the transmission rank for the PDSCH. UL RS includes DMRS and SRS. DMRS is transmitted only in the BW of the corresponding PUSCH or PUCCH transmission. The gNB can use DMRS to demodulate information in the corresponding PUSCH or PUCCH. SRS is transmitted by the UE to provide ULCSI to the gNB, and for TDD systems, SRS transmissions can also provide PMI for DL ​​transmissions. Furthermore, to establish synchronization with the gNB or initiate a higher-layer connection, the UE may transmit a Physical Random Access Channel.

[0092] In this disclosure, the beam is determined by either (1) a TCI state that establishes a quasi-cooperative positioning (QCL) relationship between a source reference signal (e.g., a synchronization signal / physical broadcast channel (PBCH) block (SSB) and / or CSI-RS) and a target reference signal; or (2) spatial relationship information that establishes an association with a source reference signal such as an SSB, CSI-RS, or SRS. In either case, the ID of the source reference signal identifies the beam.

[0093] The TCI status and / or spatial relationship reference RS can determine the spatial Rx filter used to receive downlink channels at the UE or the spatial Tx filter used to transmit uplink channels from the UE.

[0094] Version 14 LTE and Version 15 NR support up to 32 CSI-RS antenna ports, allowing eNBs to be equipped with a large number of antenna elements (such as 64 or 128). In this case, multiple antenna elements are mapped to a single CSI-RS port. For the mmWave band, although the number of antenna elements may be greater for a given form factor, the number of CSI-RS ports (which can correspond to the number of digital precoding ports) is often limited due to hardware constraints (such as the feasibility of installing a large number of ADCs / DACs at mmWave frequencies). Figure 6 As explained.

[0095] Figure 6 Example antenna structures 600 according to various embodiments of the present disclosure are described. Figure 6 The embodiment of antenna structure 600 shown is for illustrative purposes only.

[0096] In this configuration, a CSI-RS port is mapped to a large number of antenna elements that can be controlled by a set of analog phase shifters 601. A CSI-RS port can then correspond to a subarray that generates a narrow analog beam through analog beamforming 605. This analog beam can be configured to sweep across a wider range of angles 620 by changing the set of phase shifters between symbols or subframes. The number of subarrays (equal to the number of RF chains) is related to the number of CSI-RS ports N. CSI-PORT Same. Digital beamforming unit 610 penetrates N. CSI-PORT The analog beams are linearly combined to further increase the precoding gain. While the analog beams are broadband (and therefore not frequency-selective), digital precoding can span frequency subbands or resource block variations. Receiver operation can be envisioned similarly.

[0097] Because the aforementioned system utilizes multiple analog beams for transmission and reception (where one or a few analog beams are selected from a large number of analog beams, for example, periodically after a training period), the term "multi-beam operation" is used to refer to this aspect of the entire system. For illustrative purposes, this includes indicating the assigned DL or UL TX beam (also referred to as "beam indication"), measuring at least one reference signal for calculating and performing beam reports (also referred to as "beam measurements" and "beam reports," respectively), and receiving DL or UL transmissions via selecting the corresponding RX beam.

[0098] The above system is also applicable to higher frequency bands, such as above 52.6 GHz. In this case, the system can only use analog beams. Due to O2 absorption loss near 60 GHz (an additional loss of about 10 dB at a distance of 100 meters), more and sharper analog beams (and therefore a larger number of radiators in the array) may be needed to compensate for the additional path loss.

[0099] Figure 7 Examples of DUs connected to multiple RUs via a fiber-optic fronthaul link 700 according to various embodiments of this disclosure are described. Figure 7 The embodiment shown, in which a DU is connected to multiple RUs via a fiber-optic fronthaul link 700, is for illustrative purposes only.

[0100] Figure 7 The diagram depicts a distributed unit (DU) connected to multiple radio units (RUs) via a fiber-optic fronthaul link. The fronthaul carries uplink data from RUs to DUs and downlink data from DUs to RUs. For a 100 MHz X-MIMO system with 256 ports and a 30 kHz subcarrier spacing, the uplink fronthaul bandwidth requirement is more than 500 Gbps if uncompressed data transmission from all ports is required.

[0101] The RU can be implemented as a UE (e.g., as illustrated in 111 to 116) or a BS (e.g., as illustrated in 101 to 103).

[0102] RU can be implemented as UE (e.g., as...) Figure 3 (as described in the document) and BS (e.g., as...) Figure 4 (As explained in the text).

[0103] DU can be implemented as UE (e.g., as illustrated in 111 to 116) or BS (e.g., as illustrated in 101 to 103).

[0104] DU can be implemented as UE (e.g., as...) Figure 3 (as described in the document) and BS (e.g., as...) Figure 4 (As explained in the text).

[0105] Figure 8 Examples of uplink processing chain 800 according to various embodiments of the present disclosure are provided. Figure 8 The embodiment of the uplink processing chain 800 shown is for illustrative purposes only.

[0106] Figure 8 The uplink processing chain is described, in which uplink antenna data is transmitted through the RF front end and analog combiner, and A digital stream is sent to the DU via the fronthaul. In advanced 5G or 6G communications, a large number of antennas are expected to be used (e.g., ) and a large number of digital ports ( Uplink user data from all these ports must be sent via the fronthaul link, resulting in a high demand for fronthaul capacity.

[0107] In this disclosure, reversible preprocessing at RU is provided to introduce similarity into the data to aid entropy compression.

[0108] In this disclosure, uplink wireless data is mapped to red, green, and blue (RGB) values ​​to optimize video compression performance.

[0109] In this disclosure, compression at RU is determined based on the following: (1) Preprocessing: Reversible preprocessing is performed at RU to facilitate bit compression; (2) (I, Q) → (R, G, B) mapping: Bit-domain transformation maps I / Q data to the color domain; (3) Residual: in terms of size (User-defined parameters) blocks of data are processed, and differential encoding is performed on the blocks (the blocks are differentially divided consecutively, where the first processed block remains unchanged); (4) Scaling and quantization: Integer transformation and quantization (least significant bit (LSB) truncation) are performed on the data bits to increase compressibility. This step introduces loss in compression; and (5) Entropy coding: Entropy coding methods, such as context-adaptive variable-length coding (CAVLC), context-adaptive binary arithmetic coding (CABAC), or Huffman coding, are used to further compress the data losslessly.

[0110] In this disclosure, the encoded bits at the end of step 5 are sent via the fronthaul link. Decompression at DU is determined based on the following: (1) Decoding bits: Decoding the encoded bits; (2) Inverse scaling: Scaling to recover the residual; (3) Accumulation: For By residual Add to the restored block To restore blocks ; and (4) (R, G, B) → (I, Q) mapping: bit-domain transformation will restore color gamut data (i.e. (R, G, B)) and map it back to the I / Q domain.

[0111] Figure 9 Examples of fronthaul compression blocks integrated into the uplink processing chain at RU 900 according to various embodiments of the present disclosure are shown. Figure 9 The example shown, which integrates the fronthaul compression block into the uplink processing chain at RU 900, is for illustrative purposes only.

[0112] Figure 10Examples illustrating the sequence of steps in the forward compression at RU 1000 according to various embodiments of this disclosure. Figure 10 The example of the step sequence in the forward compression at RU 1000 shown is for illustrative purposes only. Figure 10 The sequence of steps in the forward compression at the RU for this embodiment is described. In some embodiments, this may be omitted. Figure 10 Some of the blocks shown.

[0113] In this disclosure, RU processing is provided.

[0114] In one embodiment, digital preprocessing is provided. In digital preprocessing, channel estimation is used to digitally preprocess the raw data from the antenna ports to induce correlations between the antenna ports. The preprocessing operation can satisfy three conditions: (1) reversibility, (2) transparency, and (3) similarity. The operation can be reversible to ensure no information loss. The operation can be transparent, so the DU can process its data without knowing the preprocessing. Finally, the operation may induce the correlations required for data compression.

[0115] Any preprocessing step for multiplication of full-rank square matrices can satisfy the first two requirements. The matrix can be appropriately chosen to satisfy the third requirement.

[0116] In one embodiment, a channel inversion method that removes channel effects is used. The transmitted signal is available as a repetition across multiple antenna ports. For a given resource element, the antenna digital ports ( The data at position ) is given by Y, as shown below: Where H is the channel matrix, L is the uplink data layer number, X is the transmitted signal, I is the inter-cell interference, and N is the thermal noise. , determined as The channel submatrix ( ).

[0117] Now, the channel reversal operation is implemented as .

[0118] This results in the data notation being repeated for each layer. To estimate the clean signal, the first column is replaced with the average of the columns:

[0119] .

[0120] In another embodiment, a channel matching method that removes channel phase is used. The transmitted signal is combined from multiple antennas and is available as an approximate repetition across multiple antenna ports. The data at the antenna digital ports is given by Y: .

[0121] Now, the channel matching operation is performed as follows:

[0122] .

[0123] This results in similar data symbols being repeated for each layer. To clearly estimate the signal, the first column is replaced with the average of the columns:

[0124] .

[0125] In one embodiment, matrix Each row represents a unique data layer. Each resource element, including a single subcarrier and OFDM symbol, corresponds to... One implementation. Therefore, the dimension of data in a time slot is ,in, It is the number of subcarriers, and This refers to the number of OFDM symbols in the time slot. For each OFDM symbol and data layer, the subsequent steps are executed in parallel. In this operation, data corresponds to OFDM symbols and data layers as streams, where each stream has a dimension. .

[0126] The DU instructs the RU via control signaling to select the specific digital preprocessing to be performed.

[0127] In one embodiment, an (I, Q) → (R, G, B) mapping is provided. In this embodiment, various transformations can be used to transform the I / Q data into color gamut data. These data samples in each stream are represented using 12 bits for the I component and 12 bits for the Q component.

[0128] In one embodiment, such as Figure 11 As shown (for example, Figure 11 For the signed values ​​of I and Q, the mapping is as follows: (a) R = I(2:9); (b) G = Q(2:9); and (c) B = [I(1,10,11,12)Q(1,10,11,12)].

[0129] In one embodiment, such as Figure 11 As shown (for example, Figure 11 For unsigned values ​​of I and Q, the mapping is as follows: (a) R = I(1:8); (b) G = Q(1:8); and (c) B = [I(9:12)Q(9:12)].

[0130] In one embodiment, such as Figure 11 As shown (for example, Figure 11For unsigned values ​​of I and Q, the mapping is as follows: (a) R = I, and (b) G = Q.

[0131] The DU indicates to the RU the selection of the (I, Q) to (R, G, B) mapping to be used via control signaling.

[0132] In one embodiment, differential coding is provided. In this embodiment, each stream of color gamut data (e.g., R, G, or B) is divided into a size comprising data in a single port and N subcarriers. The data block. Indicates from arrive port And subcarrier data. In this embodiment, for ,for residual Provided as and .

[0133] In some embodiments, the differential encoding step can be skipped, and the data can be directly passed to subsequent processing steps. The choice to perform differential encoding is indicated to the RU by the DU using a 1-bit flag.

[0134] In one embodiment, transformation and scaling are provided. In this embodiment, each data block is transformed and scaled after the residuals are obtained. In one embodiment, the scaled discrete cosine transform (DCT) is used to transform the residuals. In another embodiment, the scaled discrete fourier transform (DFT) or fast fourier transform (FFT) is used to transform the I / Q residuals, in addition to using (I, Q) → (R, G, B) mapping type 3. In yet another embodiment, integer transformations are considered identical, i.e., no transformation is performed.

[0135] After the transformation, each block is then shrunk and quantized, resulting in a many-to-one mapping. This reduces the entropy of the data and has a lossy compression effect. The number of bits truncated from the residual can be represented by QP. For example, This indicates that two LSB bits are truncated from the residual, which corresponds to scaling. Adjusting the QP based on statistical data can achieve a good balance between compression ratio and compression loss.

[0136] The DU indicates to the RU the selection of the integer transformation to be used via control signaling.

[0137] In some embodiments, the DU indicates the value of the QP to be used to the RU via control signaling. In another embodiment, the value of the QP is autonomously selected by the RU and is indicated as part of a segment extension or as the header of a compressed bit stream sent by the RU to the DU.

[0138] In one embodiment, entropy coding is provided. In this embodiment, a variant of context-adaptive variable-length coding (CAVLC) is used to losslessly compress data into bits. The encoding process sequentially modulates the size... The data blocks are processed, and this includes several steps, such as... Figure 11 The description.

[0139] Figure 11 Examples illustrating the encoding process 1100 according to various embodiments of this disclosure. Figure 11 The embodiment of the encoding process 1100 shown is for illustrative purposes only.

[0140] In the first step, the total number of non-zero coefficients ( ) and the total number of trailing 1s ( The tuple is encoded using a prefixless code, which uses a predefined lookup table to encode each tuple. Mapped into a bit sequence.

[0141] In the second step, use Each sign bit encodes the sign following a 1.

[0142] In the third step, all non-zero coefficients except for the trailing 1 are... The amplitude and sign are encoded in reverse order. An example of this encoding is described in Table 1.

[0143] In the fourth step, the total number of zeros before the last non-zero coefficient in the block is encoded using a prefixless code that maps the number of non-zero coefficients to a bit sequence using a predefined lookup table.

[0144] In the fifth step, a prefixless code is used to jointly encode each zero run between two consecutive non-zero coefficients (i.e., the number of zeros between two non-zero coefficients) and the number of remaining zeros. This prefixless code is mapped to the bit sequence using a predefined lookup table.

[0145] In another embodiment, Huffman coding is used to encode each data sample. Unprefixed codes are generated offline, mapping each data sample to a bit sequence using a predefined lookup table. Multiple lookup tables can be used, with the choice varying depending on the operating SNR, the scenario (line-of-sight (LOS) / non-line-of-sight (NLOS) and the number of data layers), and the choice of RU preprocessing. In one embodiment, the lookup table can be refreshed / updated as more data streams are observed.

[0146] In another embodiment, entropy coding is skipped, and uniform coding is used to convert data samples into a bit stream. For example, data samples ranging from -2048 to +2047 can be uniformly encoded using 12 bits each.

[0147] The DU can use control signaling to indicate specific options for entropy coding to the RU. In another embodiment, the RU can autonomously decide whether to perform entropy coding or uniform binary coding, and indicate this decision via one bit in the header.

[0148] The DU instructs the RU via control signaling to select a lookup table for entropy coding.

[0149] Table 1. Coding Levels

[0150]

[0151]

[0152] Figure 12 Examples illustrating the decoding process 1200 according to various embodiments of this disclosure. Figure 12 The embodiment of the decoding process 1200 shown is for illustrative purposes only.

[0153] In one embodiment, DU processing is provided.

[0154] Decoding follows a similar sequence of steps as encoding, such as... Figure 12 The description.

[0155] In the first step, the relevant lookup table is used to count the total number of non-zero coefficients. ( ) and the total number of trailing 1s ( Decode it.

[0156] In the second step, use the following The units digit is decoded by the symbol following the 1.

[0157] In the third step, all non-zero coefficients except for the trailing 1 are... The amplitude and sign are decoded. Table 2 explains one example of this encoding.

[0158] In the fourth step, the total number of zeros before the last non-zero coefficient in the block is decoded using the relevant lookup table.

[0159] In the fifth step, each zero run between two consecutive non-zero coefficients (i.e., the number of zeros between the two non-zero coefficients) and the number of remaining zeros are decoded. Based on the run length information, an appropriate number of zeros are placed between the decoded non-zero coefficients to recover the length. The block.

[0160] In another embodiment, if Huffman coding is used to encode each data sample, decoding is performed sample by sample using the corresponding lookup table.

[0161] Table 2. Decoding Levels

[0162]

[0163] In one embodiment, an inverse integer transformation and scaling are provided. In this embodiment, the decoded block is scaled according to the QP parameters. This is equivalent to appending zeros to the bit representation of each sample in the block. This is because the original bits of the residual transform block are effectively replaced with zeros, which is a lossy operation in the algorithm.

[0164] After scaling, the inverse operation of the integer transformation is performed. The implementation of the inverse transformation is based on the implementation of the forward transformation performed during encoding. This is because the inverse integer transformation cannot completely and precisely reverse the effects of the integer transformation performed during encoding; rather, it is a lossy operation. Entropy decoding is performed sequentially to return the residual blocks in transmission order. .

[0165] In one embodiment, accumulation is provided. In this embodiment, for and for ,piece Accumulated and obtained As and .

[0166] In one embodiment, a (R, G, B) → (I, Q) mapping is provided. In this embodiment, the stream of color data is converted back to I / Q samples by performing the inverse operation of the mapping used during encoding. All embodiments of this mapping and inverse mapping are one-to-one and therefore lossless.

[0167] In one embodiment, the inverse mapping is: (a) I = (2) B(1)-1) [RB(2:4)] and (b) Q = (2 B(5)-1) [GB (6:8)].

[0168] In one embodiment, the inverse mapping is: (a) I = [RB(1:4)] and (b) Q = [GB(5:8)].

[0169] In one embodiment, the inverse mapping is: (a) I = R, and (b) Q = G.

[0170] Figure 13Another example of the decoding process 1300 according to various embodiments of the present disclosure is described. Figure 13 The example of the decoding process 1300 shown is for illustrative purposes only.

[0171] Figure 14 Examples illustrating the sequence of steps in the forward compression at RU 1400 according to various embodiments of this disclosure. Figure 14 The example of the sequence of steps in the forward compression at RU 1400 shown is for illustrative purposes only.

[0172] In one embodiment, a (I, Q) → (H, S, V) → (R, G, B) mapping is provided. In this embodiment, data samples in each stream are represented using 12 bits for the I component and 12 bits for the Q component. These samples are first converted to the HSV domain and then to the RGB domain.

[0173] In one embodiment, the first transformation is performed as: (1) H = tan -1 (2) V = 1; and (3) S = .

[0174] In one embodiment, each (H, S, V) is represented by 12 bits.

[0175] In one embodiment, the second transformation is performed as: (1) C = V S; (2) X = C (1-|1-(H / 60°)mod2|); (3) M = V – C; (4) ; (5) (6) ; and (7) .

[0176] In one embodiment, residual calculation is provided. In this embodiment, the same operation as in [T-REC-H.264] is performed for residual calculation.

[0177] In one embodiment, transformation and scaling are provided. In this embodiment, the same operations as in [T-REC-H.264] are performed for transformation and scaling.

[0178] In one embodiment, entropy coding is provided. In this embodiment, the same entropy coding discussed in the embodiments above is implemented.

[0179] In one embodiment of DU processing, decoding is provided. In this embodiment, decoding follows a sequence similar to that described in the embodiments above.

[0180] In one embodiment, inverse integer transformation and scaling are provided. In this embodiment, the same operations as in [T-REC-H.264] are performed for the inverse transformation and scaling.

[0181] In one embodiment, a prediction is provided. In this embodiment, the same operation as in [T-REC-H.264] is performed for the prediction.

[0182] In one embodiment, a (R, G, B) → (H, S, V) → (I, Q) mapping is provided. In this embodiment, the stream of color data is converted back to I / Q samples by performing the inverse operation of the mapping used during encoding.

[0183] In one embodiment, the RGB to HSV conversion is performed as follows: (1) Cmax = max(R, G, B); (2) Cmin = min(R, G, B); (3) Cmax - Cmin; (4) V = Cmax;

[0184] (5) ;and

[0185] (6) .

[0186] Then, the HSV to IQ conversion is performed as follows: (1) I = S cos(H) and (2)Q = S sin(H).

[0187] Figure 15 Examples of RU architecture and algorithm 1500 according to various embodiments of this disclosure are provided. Figure 15 The RU architecture and algorithm 1500 shown in the embodiments are for illustrative purposes only. Figure 15 As shown, block floating-point (BFP) compression is performed. Data from each SC is reduced from a 12-bit representation to a 9-bit mantissa, and a common 4-bit exponent is used per PRB.

[0188] Figure 16 Examples of compressed bit widths of 1600 according to various embodiments of this disclosure are described. Figure 16 The illustrated example with a compressed bit width of 1600 is for illustrative purposes only. Figure 16 As shown, 12 samples are used for uncompressed signed bit width.

[0189] Figure 17 Examples of H.264 architecture 1700 according to various embodiments of this disclosure are provided. Figure 17 The H.264 architecture 1700 example shown is for illustrative purposes only. Figure 17As shown, YCbCr is separated into "Y" and "Cr,Cr". (The rest of the text appears to be a typographical error and doesn't translate directly.) Figure 17 As shown, each branch of YCbCr is processed by several function blocks. For Cb and Cr, Hadamard or DCT transformations are applied (only for DC coefficients).

[0190] Figure 18 Examples of color mapping 1800 according to various embodiments of the present disclosure are provided. Figure 18 The illustrated example of color mapping 1800 is for illustrative purposes only. Figure 18 As shown, determine the following: (1) H = angle (I+jQ); (2) V = 1; (3) S = I2+Q2; and (4) convert from HSV (12-bit) to RGB (8-bit).

[0191] Figure 19 Examples illustrating an unprocessed NMSE compression ratio tradeoff of 1900 according to various embodiments of this disclosure. Figure 19 The example shown with an NMSE compression ratio tradeoff of 1900 without preprocessing is for illustrative purposes only.

[0192] Figure 20 Examples of NMSE compression ratio trade-offs with channel inversion and channel matching according to various embodiments of this disclosure are provided. Figure 20 The example shown with the NMSE compression ratio tradeoff of channel inversion and channel matching is for illustrative purposes only.

[0193] like Figure 19 and Figure 20 As illustrated, a higher Rx SNR generally indicates a better CR-NMSE tradeoff, and mapping 1 generally indicates a better tradeoff than mapping 2. Furthermore, channel reversal generally performs better than channel matching.

[0194] Figure 21 A flowchart illustrating an RU method 2100 for bit compression of uplink fronthaul data according to various embodiments of the present disclosure is provided. The RU method 2100 can be derived from an RU (e.g., such as...). Figure 1 The UEs 111 to 116 described herein shall be used to execute this. Figure 21 The embodiments of the RU method 2100 described herein are for illustrative purposes only. Figure 21 One or more of the components described may be implemented in a dedicated circuit configured to perform the function, or one or more of the components may be implemented by one or more processors that execute instructions to perform the function.

[0195] In one embodiment, the RU can be implemented as a UE (e.g., as shown in the figure). Figure 1 As shown in 111 to 116), BS (e.g., as Figure 1Electronic devices (shown as 101 to 103) or implemented in a UE or BS.

[0196] In one embodiment, the DU can be implemented as a UE (e.g., as...). Figure 1 As shown in 111 to 116), BS (e.g., as Figure 1 Electronic devices (shown as 101 to 103) or implemented in a UE or BS.

[0197] like Figure 21 As shown, RU method 2100 begins at step 2102. In step 2102, the RU identifies uplink fronthaul data to reduce the data load on the uplink fronthaul link, wherein the uplink fronthaul link is between the RU and the DU.

[0198] In step 2104, the RU processes the uplink forward data to obtain a representative set of values ​​for the compression operation;

[0199] In step 2106, RU selects at least one encoding parameter for the compression operation based on a set of representative values.

[0200] In step 2108, the RU sends uplink fronthaul data compressed based on the compression operation to the DU.

[0201] In one embodiment, the RU performs digital preprocessing operations using uplink fronthaul data to induce similarity in at least one of the frequency domain, time domain, and antenna domain of the uplink fronthaul data and to map the I / Q values ​​included in the uplink fronthaul data to representative RGB values.

[0202] In this embodiment, the digital preprocessing operations include reversible operations to reduce information loss and transparent operations to balance uplink fronthaul data, including I / Q values.

[0203] In this embodiment, the digital preprocessing operation includes: a channel inversion operation, which includes a channel measurement operation and a first preprocessing operation; and a channel matching operation, which includes a channel measurement operation and a second preprocessing operation.

[0204] In one embodiment, a representative set of bits for RGB values ​​is mapped to: a first sample comprising (i) 8 bits for the R value in the MSB and (ii) 4 bits for the B value, including a sign bit and 3 bits in the LSB; and a second sample comprising (i) 8 bits for the G value in the MSB and (ii) 4 bits for the B value, including a sign bit and 3 bits in the LSB; a first sample comprising (i) 8 bits for the R value in the MSB and (ii) 4 bits for the B value in the LSB; and a second sample comprising (i) 8 bits for the G value in the MSB and (ii) 4 bits for the B value in the LSB; or a first sample comprising 12 bits for the R value; and a second sample comprising 12 bits for the G value.

[0205] In one embodiment, the RU selects an entropy coding scheme to compress the uplink fronthaul data into information bits for the compression operation.

[0206] In this embodiment, the entropy coding scheme includes at least one of the following: a context-aware variable-length coding scheme supporting a block size of 256, a Huffman coding scheme, and an arithmetic coding scheme.

[0207] In one embodiment, the RU performs an LSB truncation operation to increase the compression ratio for compression operations.

[0208] In one embodiment, the RU selects a differential coding scheme to compute the residual of the uplink fronthaul data for compression operations.

[0209] Figure 22 This is a block diagram of the internal configuration of a base station according to an embodiment.

[0210] like Figure 22 As shown, a base station according to an embodiment may include a transceiver 2210, a memory 2220, and a processor (or controller) 2230. The transceiver 2210, memory 2220, and processor 2230 (or controller) of the base station can operate according to the communication method of the base station described above. However, the components of the base station are not limited thereto. For example, the base station may include more or fewer components than described above. Furthermore, the processor 2230, transceiver 2210, and memory 2220 may be implemented as a single chip. Additionally, the processor 2230 may include at least one processor.

[0211] Transceiver 2210 is collectively referred to as a base station receiver and a base station transmitter, and can transmit signals to / receive signals from a terminal. Signals transmitted to or received from a terminal may include control information and data. Transceiver 2210 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal and an RF receiver for amplifying the received signal with low noise and down-converting the frequency. However, this is merely an example of transceiver 2210, and the components of transceiver 2210 are not limited to RF transmitters and RF receivers.

[0212] In addition, transceiver 2210 can receive signals via a wireless channel and output them to processor 2230, and can also transmit signals output from processor 2230 via a wireless channel.

[0213] The memory 2220 can store programs and data required for the operation of the base station. Furthermore, the memory 2220 can store control information or data included in signals acquired by the base station. The memory 2220 can be a storage medium such as a read-only memory (ROM), random access memory (RAM), hard disk, CD-ROM, DVD, or a combination of storage media.

[0214] Processor 2230 can control a series of processes to enable the base station to operate as described above. For example, transceiver 2210 can receive data signals and / or control signals transmitted by the terminal, and processor 2230 can determine the result of receiving signals transmitted by the terminal and / or core network functions.

[0215] Figure 23 This is a block diagram illustrating the internal structure of a terminal according to an embodiment of the present disclosure.

[0216] like Figure 23 As shown, the terminal disclosed herein may include a transceiver 2310, a memory 2320, and a processor (or controller) 2330. The transceiver 2310, memory 2320, and processor (or controller) 2330 of the terminal can operate according to the communication method of the terminal described above. However, the components of the terminal are not limited thereto. For example, the terminal may include more or fewer components than described above. Furthermore, the processor 2330, transceiver 2310, and memory 2320 may be implemented as a single chip. Additionally, the processor 2330 may include at least one processor.

[0217] Transceiver 2310 is collectively referred to as a terminal receiver and a terminal transmitter, and can transmit signals to / receive signals from a base station. Signals transmitted to or received from a base station may include control information and data. For this purpose, transceiver 2310 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal and an RF receiver for amplifying the received signal with low noise and down-converting the frequency. However, this is merely an example of transceiver 2310, and the components of transceiver 2310 are not limited to RF transmitters and RF receivers.

[0218] In addition, transceiver 2310 can receive signals via a wireless channel and output them to processor 2330, and can also transmit signals output from processor 2330 via a wireless channel.

[0219] The memory 2320 can store programs and data required for the operation of the terminal. Furthermore, the memory 2320 can store control information or data included in signals received by the terminal. The memory 2320 can be a storage medium such as ROM, RAM, hard disk, CD-ROM, DVD, or a combination of storage media.

[0220] The processor 2330 can control a series of processes to enable the terminal to operate as described above. For example, the transceiver 2310 can receive data signals and / or control signals, and the processor 2330 can determine the result of receiving signals transmitted by the base station and / or another terminal.

[0221] The methods described in the embodiments according to the appended claims or detailed description of this disclosure may be implemented in hardware, software, or a combination of hardware and software.

[0222] Programs (e.g., software modules or software) can be stored in random access memory (RAM), non-volatile memory including flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), disk storage devices, optical disc-ROM (CD-ROM), digital versatile disc (DVD), another type of optical storage device, or magnetic tape. Alternatively, programs can be stored in a memory system comprising a combination of some or all of the above storage devices. Furthermore, each memory device can include multiple such devices.

[0223] The program can also be stored on an attachable storage device accessible via a communication network, such as the Internet, intranet, local area network (LAN), wireless LAN (WLAN), or storage area network (SAN) or a combination thereof. According to embodiments of this disclosure, the storage device can be connected to the device via an external port. Another storage device on the communication network can also be connected to the device executing embodiments of this disclosure.

[0224] Those skilled in the art will understand that the illustrative embodiments described above are not intended to be limiting. It should be understood that any two or more embodiments disclosed herein can be combined in any combination. Furthermore, other embodiments can be utilized and other changes can be made without departing from the spirit and scope of the subject matter presented herein. It will be readily understood that aspects of the invention disclosed herein, as generally described herein and illustrated in the accompanying drawings, can be arranged, substituted, combined, separated, and designed in a variety of different configurations, all of which are contemplated herein.

[0225] Those skilled in the art will understand that the various illustrative logic blocks, modules, circuits, and steps described herein can be implemented in hardware, software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps are generally described above as sets of functions. Whether such sets of functions are implemented in hardware or software depends on the specific application and the design constraints imposed on the system as a whole. Those skilled in the art may implement the described sets of functions in different ways for each specific application, but such design decisions should not be construed as departing from the scope of this application.

[0226] The various illustrative logic blocks, modules, and circuits described in this application may be implemented or performed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in alternative examples, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration.

[0227] When electrical structures and methods are implemented in software, a computer-readable recording medium on which one or more programs (software modules) are recorded can be provided. The one or more programs recorded on the computer-readable recording medium are configured to be executed by one or more processors in an electronic device. The one or more programs include instructions for performing the methods according to the embodiments described in the specific description of this disclosure.

[0228] In the foregoing embodiments of this disclosure, the elements included in this disclosure are expressed in singular or plural form according to the embodiments. However, for ease of explanation, singular or plural forms are suitably chosen, and this disclosure is not limited thereto. Thus, elements expressed in plural form may also be configured as a single element, and elements expressed in singular form may also be configured as multiple elements.

[0229] The flowcharts above illustrate example methods that can be implemented according to the principles of this disclosure, and various modifications can be made to the methods illustrated in the flowcharts herein. For example, although shown as a series of steps, the individual steps in each diagram may overlap, appear in parallel, appear in different orders, or appear multiple times. In another example, steps may be omitted or replaced by other steps.

[0230] Although this disclosure has been described with reference to exemplary embodiments, various changes and modifications may be suggested to those skilled in the art. This disclosure is intended to cover such changes and modifications that fall within the scope of the appended claims. Nothing described in this application should be construed as implying that any particular element, step, or function is an essential element that must be included within the scope of the claims. The scope of the patent subject matter is defined by the claims.

Claims

1. A radio unit RU in a wireless communication system, the RU comprising: The processor is configured as follows: Identifying uplink fronthaul data to reduce data load on the uplink fronthaul link, wherein the uplink fronthaul link is between the RU and the distributed unit DU. Process the uplink fronthaul data to obtain a representative set of values ​​for the compression operation, and At least one encoding parameter for the compression operation is selected based on the representative value set; and A transceiver, operably coupled to the processor, is configured to send uplink fronthaul data compressed based on the compression operation to the DU.

2. The RU according to claim 1, wherein, The processor is also configured to: Digital preprocessing operations are performed on the uplink fronthaul data to induce similarity of the uplink fronthaul data in at least one of the frequency domain, time domain, and antenna domain. as well as The in-phase and quadrature I / Q values ​​included in the uplink fronthaul data are mapped to representative red, green, and blue (RGB) values.

3. The RU according to claim 2, wherein, The digital preprocessing operations include: The channel inversion operation includes channel measurement operations and a first preprocessing operation; and The channel matching operation includes the channel measurement operation and the second preprocessing.

4. The RU according to claim 2, wherein, The representative set of bits for the RGB values ​​is mapped to: The first sample comprises (i) 8 bits of the most significant bit (MSB) for the red (R) value and (ii) 4 bits of the blue (B) value, including the sign bit and 3 bits of the least significant bit (LSB); and the second sample comprises (i) 8 bits of the MSB for the green (G) value and (ii) 4 bits of the B value, including the sign bit and 3 bits of the LSB. The first sample includes (i) 8 bits of the MSB for the R value and (ii) 4 bits of the LSB for the B value; And the second sample, comprising (i) 8 bits of the MSB for the G value and (ii) 4 bits of the LSB for the B value; or The first sample includes 12 bits for the R value; and the second sample includes 12 bits for the G value.

5. The RU according to claim 2, wherein, The digital preprocessing operations include reversible operations to reduce information loss and transparent operations to balance the uplink fronthaul data, which includes the I / Q values.

6. The RU according to claim 1, in, The processor is also configured to select an entropy coding scheme to compress the uplink fronthaul data into information bits specific to the compression operation. The entropy coding scheme includes at least one of the following: a context-aware variable-length coding scheme supporting a block size of 256, a Huffman coding scheme, and an arithmetic coding scheme.

7. The RU according to claim 1, wherein, The processor is also configured to perform a least significant bit (LSB) truncation operation to increase the compression ratio for the compression operation.

8. A method for using a radio unit RU in a wireless communication system, the method comprising: Identify uplink fronthaul data to reduce data load on the uplink fronthaul link, wherein the uplink fronthaul link is between the RU and the distributed unit (DU); Process the uplink fronthaul data to obtain a representative set of values ​​for the compression operation; At least one encoding parameter for the compression operation is selected based on the representative value set; and Send the uplink fronthaul data compressed based on the compression operation to the DU.

9. The method according to claim 8, further comprising: Digital preprocessing operations are performed on the uplink fronthaul data to induce similarity of the uplink fronthaul data in at least one of the frequency domain, time domain, and antenna domain. as well as The in-phase and quadrature I / Q values ​​included in the uplink fronthaul data are mapped to representative red, green, and blue (RGB) values.

10. The method according to claim 9, wherein, The digital preprocessing operations include: The channel inversion operation includes channel measurement operations and a first preprocessing operation; and The channel matching operation includes the channel measurement operation and the second preprocessing.

11. The method according to claim 9, wherein, The representative set of bits for the RGB values ​​is mapped to: The first sample comprises (i) 8 bits of the most significant bit (MSB) for the red (R) value and (ii) 4 bits of the blue (B) value, including the sign bit and 3 bits of the least significant bit (LSB); and the second sample comprises (i) 8 bits of the MSB for the green (G) value and (ii) 4 bits of the B value, including the sign bit and 3 bits of the LSB. The first sample includes (i) 8 bits of the MSB for the R value and (ii) 4 bits of the LSB for the B value; And the second sample, comprising (i) 8 bits of the MSB for the G value and (ii) 4 bits of the LSB for the B value; or The first sample includes 12 bits for the R value; and the second sample includes 12 bits for the G value.

12. The method according to claim 9, wherein, The digital preprocessing operations include reversible operations to reduce information loss and transparent operations to balance the uplink fronthaul data, which includes the I / Q values.

13. The method of claim 8, further comprising: An entropy coding scheme is selected to compress the uplink fronthaul data into information bits specific to the compression operation. The entropy coding scheme includes at least one of the following: a context-aware variable-length coding scheme supporting a block size of 256, a Huffman coding scheme, and an arithmetic coding scheme.

14. A non-transitory computer-readable medium comprising program code, which, when executed by at least one processor of an electronic device, causes the electronic device to: Identify uplink fronthaul data to reduce data load on the uplink fronthaul link, whereby... The uplink fronthaul link is located between the radio unit (RU) and the distributed unit (DU); Process the uplink fronthaul data to obtain a representative set of values ​​for the compression operation; At least one encoding parameter for the compression operation is selected based on the representative set of values. as well as Send the uplink fronthaul data compressed based on the compression operation to the DU.

15. The non-transitory computer-readable medium of claim 19, further comprising program code, which, when executed by the at least one processor, causes the electronic device to: Digital preprocessing operations are performed on the uplink fronthaul data to induce similarity in at least one of the frequency, time, and antenna domains of the uplink fronthaul data; and The in-phase and quadrature (I / Q) values ​​included in the uplink fronthaul data are mapped to representative red, green, and blue (RGB) values.

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