CN117354094A - Wireless communication method, user equipment and storage medium - Google Patents

Abstract

The invention provides a wireless communication method, user equipment and a storage medium. Wherein a wireless communication method is used for user equipment, comprising: receiving a second baseband signal carried on a second carrier frequency transmitted by at least one repeater, wherein the second baseband signal carries a data signal transmitted by a base station and is derived from a first baseband signal carried on a first carrier frequency transmitted by the base station; estimating a common phase error, CPE, in a first set of orthogonal frequency division multiplexing, OFDM, symbols based on a phase tracking reference signal, PT-RS, included in the received second baseband signal, wherein the PT-RS is transmitted by the base station on the first carrier frequency and forwarded to the user equipment, UE, on the second carrier frequency by the at least one repeater; and detecting the data signal based on the received second baseband signal and the estimated CPE in the first set of OFDM symbols. By utilizing the invention, the system performance can be improved.

Description

Wireless communication method, user equipment and storage medium

Technical Field

The present invention relates generally to communication systems, and more particularly to techniques for forming distributed MIMO receivers.

Background

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcast. A typical wireless communication system may employ multiple access techniques capable of supporting communication with multiple users by sharing the available system resources. Examples of such multiple access techniques include code division multiple access (code division multiple access, CDMA) systems, time division multiple access (time division multiple access, TDMA) systems, frequency division multiple access (frequency division multiple access, FDMA) systems, orthogonal frequency division multiple access (orthogonal frequency division multiple access, OFDMA) systems, single-carrier frequency division multiple access (single-carrier frequency division multiple access, SC-FDMA) systems, and time division synchronous code division multiple access (time division synchronous code division multiple access, TD-SCDMA) systems.

These multiple access techniques have been employed in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, or even global level. An example of a telecommunications standard is the 5G New Radio (NR). The 5G NR is part of the continuous mobile broadband evolution promulgated by the third generation partnership project (third generation partnership project,3 GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the internet of things) and other requirements. Some aspects of 5G NR may be based on the 4G long term evolution (long term evolution, LTE) standard. Further improvements in the 5G NR technology are needed. These improvements are also applicable to other multiple access techniques and telecommunication standards employing these techniques.

Disclosure of Invention

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

In one aspect of the invention, a method, computer-readable medium, and apparatus are provided. The apparatus may be a UE. The UE receives a second carrier frequency (f ₂ ) And a second baseband signal carried thereon. The second baseband signal carries a data signal transmitted from a base station and is based on a first carrier frequency (f ₁ ) And the first baseband signal carried on the carrier is obtained. The UE estimates a common phase error CPE in the first set of orthogonal frequency division multiplexing, OFDM, symbols based on a phase tracking reference signal PT-RS included in the received second baseband signal. The PT-RS is transmitted by the base station at the first carrier frequency (f ₁ ) And transmitted over the second carrier frequency (f by the at least one repeater ₂ ) And forwarding to the UE. The UE detects a data signal based on the received second baseband signal and the estimated CPE in the first set of OFDM symbols.

In another aspect of the invention, a method, computer-readable medium, and apparatus are provided. The apparatus may be a base station. The base station receives the signal at a first carrier frequency (f ₁ ) A first baseband signal carried thereon, wherein the first baseband signal is based on a second carrier frequency (f ₂ ) And the second baseband signal carried on the carrier. The base station estimates CPE in a first set of OFDM symbols for a respective link between the UE and the base station through each of the at least one repeater. The estimation is based on the PT-RS associated with the repeater in the received first baseband signal. PT-RS is transmitted by the UE on the second carrier frequency (f ₂ ) And transmitted over the first carrier frequency (f by the repeater ₁ ) And forwarding to the base station. The base station compensates for the first baseband signal received from each repeater based on the estimated CPE associated with the respective link between the UE and the base station through that repeater.

In yet another aspect of the present invention, there is provided a method of Methods, computer-readable media, and apparatus. The device may be a wireless device. The wireless device is at the second carrier frequency f ₂ And receiving a second baseband signal from the user equipment. The wireless device estimates CPE in the first set of OFDM symbols based on the PT-RS in the received second baseband signal. The wireless device compensates the received second baseband signal for CPE in the estimated first set of OFDM symbols. The wireless device maps the compensated second baseband signal to a signal to be at the first carrier frequency f ₁ Up to a first baseband signal transmitted to a base station.

To the accomplishment of the foregoing and related ends, one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed and this description is intended to include all such aspects and their equivalents.

Drawings

Fig. 1 is a schematic diagram illustrating a wireless communication system and an access network.

Fig. 2 is a block diagram illustrating a base station in an access network in communication with a UE.

Fig. 3 illustrates an example logical architecture of a distributed access network.

Fig. 4 illustrates an example physical architecture of a distributed access network.

Fig. 5 illustrates an example diagram of DL-centric time slots.

Fig. 6 illustrates an example diagram of UL-centric time slots.

Fig. 7 is a schematic diagram illustrating downlink MIMO transmissions from a base station to a UE via one or more repeaters.

Fig. 8 is a schematic diagram illustrating downlink transmission timing from a base station to a UE via one or more repeaters.

Fig. 9 is a diagram illustrating PRBs transmitted in a slot by a base station.

Fig. 10 is a schematic diagram illustrating uplink MIMO transmissions from a UE to a base station via one or more repeaters.

Fig. 11 is a schematic diagram illustrating uplink timing from a UE to a base station via one or more repeaters.

Fig. 12 is a schematic diagram illustrating signal transformation at a repeater.

Fig. 13 is a diagram illustrating PRBs transmitted by a UE in a slot.

Fig. 14 is a flow chart of a method (procedure) for downlink CPE estimation and compensation.

Fig. 15 is a flow chart of a method (procedure) for uplink CPE estimation and compensation.

Fig. 16 is a flow chart of another method (process) for uplink CPE estimation and compensation.

Fig. 17 is a schematic diagram illustrating a hardware implementation of a device employing a processing system.

Fig. 18 is a schematic diagram illustrating a hardware implementation of another apparatus employing a processing system.

Detailed Description

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to one skilled in the art that the concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts.

Aspects of a telecommunications system will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the figures by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

As an example, an element, any portion of an element, or any combination of elements may be implemented as a "processing system" that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (graphics processing unit, GPU), central processing units (central processing unit, CPU), application processors, digital signal processors (digital signal processor, DSP), reduced instruction set computing (reduced instruction set computing, RISC) processors, system on chip (systems on a chip, soC), baseband processors, field programmable gate arrays (field programmable gate array, FPGA), programmable logic devices (programmable logic device, PLD), state machines, gate logic (gated logic), discrete hardware circuits, and other suitable hardware configured to perform the various functions described herein. One or more processors in the processing system may execute the software. Software should be construed broadly to mean instructions, instruction sets, code segments, program code, programs, subroutines, software components, applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, and the like, whether referred to as software, firmware, middleware, microcode, hardware description language, or the like.

Accordingly, in one or more examples, the described functionality may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer readable media includes computer storage media. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise random-access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (electrically erasable programmable ROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the foregoing types of computer-readable media, or any other media that can be used to store computer-executable code in the form of computer-accessible instructions or data structures.

Fig. 1 is a schematic diagram illustrating a wireless communication system and an access network 100. A wireless communication system, also referred to as a wireless wide area network (wireless wide area network, WWAN), includes a base station 102, a UE 104, an evolved packet core (evolved packet core, EPC) 160, and another core network 190 (e.g., a 5G core (5 gc)). The base station 102 may include a macrocell (high power cellular base station) and/or a small cell (low power cellular base station). The macrocell includes a base station. Small cells include femto cells (femtocells), pico cells (picocells), and micro cells (microcells).

Base stations 102 configured for 4G LTE (collectively referred to as evolved universal mobile telecommunications system (universal mobile telecommunications system, UMTS) terrestrial radio access network (evolved UMTS terrestrial radio access network, E-UTRAN)) can interact with EPC 160 through backhaul link 132 (e.g., SI interface). A base station 102 configured for 5G NR (collectively referred to as next generation RAN (NG-RAN)) may interact with a core network 190 through a backhaul link 184. Among other functions, the base station 102 may perform one or more of the following functions: transport user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio Access Network (RAN) sharing, multimedia broadcast multicast services (multimedia broadcast multicast service, MBMS), subscriber and device tracking, RAN information management (RAN information management, RIM), paging, positioning, and delivery of alert messages. Base stations 102 may communicate with each other directly or indirectly (e.g., through EPC 160 or core network 190) over backhaul link 134 (e.g., an X2 interface). The backhaul link 134 may be wired or wireless.

The base station 102 may communicate wirelessly with the UE 104. Each base station 102 may provide communication coverage for a corresponding geographic coverage area 110. The geographic coverage areas 110 may overlap. For example, the small cell 102 'may have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network comprising small cells and macro cells may be referred to as a heterogeneous network. The heterogeneous network may also include home enbs (henbs) that may provide services to a restricted group called a closed subscriber group (closed subscriber group, CSG). The communication link 120 between the base station 102 and the UE 104 may include Uplink (UL) (also referred to as reverse link) transmissions from the UE 104 to the base station 102 and/or Downlink (DL) (also referred to as forward link) transmissions from the base station 102 to the UE 104. Communication link 120 may use multiple-input multiple-output (MIMO) antenna techniques including spatial multiplexing, beamforming, and/or transmit diversity. The communication link may be through one or more carriers. Each carrier of the base station 102/UE 104 may use a spectrum up to X MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz), where each carrier is allocated in carrier aggregation (X component carriers) up to yxmhz in total for transmission in each direction. The carriers may or may not be adjacent to each other. The carrier allocation on DL and UL may be asymmetric (e.g., DL may be allocated more or less carriers than UL). The component carriers may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell), and the secondary component carrier may be referred to as a secondary cell (SCell).

Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL/UL WWAN spectrum. The D2D communication link 158 may use one or more side link channels, such as a physical side link broadcast channel (physical sidelink broadcast channel, PSBCH), a physical side link discovery channel (physical sidelink discovery channel, PSDCH), a physical side link shared channel (physical sidelink shared channel, PSSCH), and a physical side link control channel (physical sidelink control channel, PSCCH). D2D communication may be through various wireless D2D communication systems, such as FlashLinQ, wiMedia, bluetooth, zigBee, wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

The wireless communication system may also include a Wi-Fi Access Point (AP) 150 in communication with a Wi-Fi Station (STA) 152 via a communication link 154 in the 5GHz unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152/AP 150 may perform clear channel assessment (clear channel assessment, CCA) prior to communication to determine whether a channel is available.

The small cell 102' may operate in licensed and/or unlicensed spectrum. When operating in unlicensed spectrum, the small cell 102' may employ NR and use the same 5GHz unlicensed spectrum as used by Wi-Fi AP 150. Small cells 102' employing NR in unlicensed spectrum may enhance coverage to an access network and/or increase capacity of an access network.

Base station 102 (whether small cell 102' or a large cell (e.g., macro base station)) may include an eNB, a gNB, or other type of base station. Some base stations, such as the gNB 180, may operate in the traditional sub 6GHz frequency spectrum, millimeter wave (mmW) frequencies, and/or frequencies near mmW, in communication with the UE 104. When the gNB 180 operates at or near mmW frequencies, the gNB 180 may be referred to as a mmW base station. The extremely high frequency (extremely high frequency, EHF) is part of the Radio Frequency (RF) in the electromagnetic spectrum. EHF has a wavelength in the range of 30GHz to 300GHz, between 1 mm and 10 mm. The radio waves in the frequency band may be referred to as millimeter waves. Frequencies close to mmW may extend down to frequencies of 3GHz with a wavelength of 100 mm. The ultra-high frequency (super high frequency, SHF) band lies between 3GHz and 30GHz, also known as centimetre waves. Communications using mmW/near mmW radio frequency bands (e.g., 3GHz to 300 GHz) have extremely high path loss and short distances. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for extremely high path loss and short distances.

The base station 180 may transmit the beamformed signals to the UE 104 in one or more transmit directions 108 a. The UE 104 may receive the beamformed signals from the base station 180 in one or more receive directions 108 b. The UE 104 may also transmit the beamformed signals in one or more transmit directions to the base station 180. The base station 180 may receive the beamformed signals from the UEs 104 in one or more directions. The base station 180/UE 104 may perform beam training to determine the best reception and transmission direction of the base station 180/UE 104. The transmission and reception directions of the base station 180 may be the same or different. The transmit and receive directions of the UE 104 may be the same or different.

EPC 160 may include a mobility management entity (mobility management entity, MME) 162, other MMEs 164, serving gateway 166, MBMS gateway 168, broadcast multicast service center (broadcast multicast service center, BM-SC) 170, and packet data network (packet data network, PDN) gateway 172.MME 162 may communicate with home subscriber server (home subscriber server, HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. In general, MME 162 provides bearer and connection management. All user internet protocol (Internet protocol, IP) packets are transmitted through the serving gateway 166, which serving gateway 166 itself is connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation as well as other functions. The PDN gateway 172 and BM-SC 170 are connected to an IP service 176.IP services 176 may include the internet, intranets, IP multimedia subsystem (IP multimedia subsystem, IMS), PS streaming services, and/or other IP services. The BM-SC 170 may provide functionality for MBMS user service provision and delivery. The BM-SC 170 may be used as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a public land mobile network (public land mobile network, PLMN), and may be used to schedule MBMS transmissions. The MBMS gateway 168 may be used to distribute MBMS traffic to base stations 102 belonging to a multicast broadcast single frequency network (multicast broadcast single frequency network, MBSFN) area broadcasting a particular service and may be responsible for session management (start/stop) and collecting eMBMS related charging information.

The core network 190 may include access and mobility management functions (access and mobility management function, AMF) 192, other AMFs 193, location management functions (location management function, LMF) 198, session management functions (session management function, SMF) 194, and user plane functions (user plane function, UPF) 195. The AMF 192 may communicate with a unified data management (unified data management, UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. In general, SMF194 provides QoS flows and session management. All user IP packets may be transmitted through UPF 195. The UPF 195 provides UE IP address assignment as well as other functions. The UPF 195 is connected to an IP service 197. The IP services 197 may include the internet, intranets, IMS, PS streaming services, and/or other IP services.

A base station may also be called a gNB, node B, eNB, access point, base station transceiver, radio base station, radio transceiver, transceiver function, basic service set (basic service set, BSS), extended service set (extended service set, ESS), transmission reception point (transmit reception point, TRP), or some other suitable terminology. The base station 102 provides an access point for the UE 104 to the EPC 160 or core network 190. Examples of UEs 104 include a cellular telephone, a smart phone, a session initiation protocol (session initiation protocol, SIP) phone, a laptop, a personal digital assistant (personal digital assistant, PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a car, an electricity meter, an air pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functional device. Some UEs 104 may be referred to as IoT devices (e.g., parking timers, air pumps, ovens, carts, heart monitors, etc.). The UE 104 may also be referred to as a station, mobile station, subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, or some other suitable terminology.

Although the application may refer to 5G NR, the application may be applicable to other similar fields, such as LTE, LTE-advanced (LTE-a), CDMA, global system for mobile communications (global system for mobile communications, GSM), or other wireless/radio access technologies.

Fig. 2 is a block diagram of a UE 250 in an access network in communication with a base station 210. In DL, IP packets from EPC 160 may be provided to controller/processor 275. Controller/processor 275 implements layer 3 and layer 2 functions. Layer 3 includes a radio resource control (radio resource control, RRC) layer, and layer 2 includes a packet data convergence protocol (packet data convergence protocol, PDCP) layer, a radio link control (radio link control, RLC) layer, and a medium access control (medium access control, MAC) layer. Controller/processor 275 provides RRC layer functions associated with broadcast of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection setup, RRC connection modification, and RRC connection release), inter-RAT (inter-RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification) and handover support functions; RLC layer functions associated with transmission of upper layer (upper layer) Packet Data Units (PDUs), error correction by ARQ, concatenation/segmentation and reassembly of RLC service data units (service data unit, SDU), re-segmentation of RLC data PDUs and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing MAC SDUs onto Transport Blocks (TBs), demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction by HARQ, priority handling and logical channel ordering.

A Transmit (TX) processor 216 and a Receive (RX) processor 270 implement layer 1 functions associated with various signal processing functions. Layer 1, which includes a Physical (PHY) layer, may include error detection on a transport channel, forward error correction (forward error correction, FEC) encoding/decoding of a transport channel, interleaving, rate matching, mapping onto a physical channel, modulation/demodulation of a physical channel, and MIMO antenna processing. TX processor 216 processes the mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-quadrature amplitude modulation, M-QAM)). The encoded and modulated symbols may then be separated into parallel streams, and the individual streams may then be mapped to OFDM subcarriers, multiplexed with reference signals (e.g., pilots) in the time and/or frequency domain, and combined together using an inverse fast fourier transform (inverse fast Fourier transform, IFFT) to produce a physical channel carrying the time domain OFDM symbol stream. The OFDM streams are spatially precoded to produce a plurality of spatial streams. Channel estimates from channel estimator 274 may be used to determine coding and modulation schemes, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 250. Each spatial stream may be provided to a different antenna 220 via a separate transmitter 218 TX. Each transmitter 218TX may modulate an RF carrier with a corresponding spatial stream for transmission.

At the UE 250, each receiver 254RX receives a signal through its respective antenna 252. Each receiver 254RX recovers information modulated onto an RF carrier and provides the information to an RX processor 256.TX processor 268 and RX processor 256 implement layer 1 functions associated with various signal processing functions. RX processor 256 may perform spatial processing on the information to recover any spatial streams destined for UE 250. If multiple spatial streams are destined for UE 250, they may be combined into a single OFDM symbol stream by RX processor 256. The RX processor 256 then converts the OFDM symbol stream from the time domain to the frequency domain using a fast fourier transform (fast Fourier transform, FFT). The frequency domain signal comprises separate OFDM symbol streams for each subcarrier of the OFDM signal. Symbols and reference signals on the various subcarriers are recovered and demodulated by determining the most likely signal constellation points transmitted by base station 210. These soft decisions (soft decisions) may be based on channel estimates computed by channel estimator 258. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 210 on the physical channel. Data and control signals may be provided to controller/processor 259, where controller/processor 259 implements layer 3 and layer 2 functions.

The controller/processor 259 can be associated with a memory 260 that stores program codes and data. Memory 260 may be referred to as a computer-readable medium. In the UL, controller/processor 259 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from EPC 160. The controller/processor 259 is also responsible for supporting error detection for HARQ operations using ACK and/or NACK protocols.

Similar to the functionality described in connection with DL transmission by base station 210, controller/processor 259 provides RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression/decompression and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functions associated with transmission of upper layer PDUs, error correction by ARQ, concatenation/segmentation and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing MAC SDUs onto TBs, demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction by HARQ, priority handling and logical channel ordering.

Channel estimator 258 derives channel estimates from reference signals or feedback transmitted by base station 210 that can be used by TX processor 268 to select the appropriate coding and modulation scheme and for spatial processing. The spatial streams generated by TX processor 268 may be provided to different antennas 252 via separate transmitters 254 TX. Each transmitter 254TX may modulate an RF carrier with a corresponding spatial stream for transmission. UL transmissions are processed at base station 210 in a manner similar to that described in connection with the receiver function at UE 250. Each receiver 218RX receives a signal via its respective antenna 220. Each receiver 218RX recovers information modulated onto an RF carrier and provides the information to the RX processor 270.

The controller/processor 275 may be associated with a memory 276 that stores program codes and data. Memory 276 may be referred to as a computer-readable medium. In the UL, the controller/processor 275 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 250. IP packets from controller/processor 275 may be provided to EPC 160. The controller/processor 275 is also responsible for supporting error detection for HARQ operations using ACK and/or NACK protocols.

NR may refer to a radio configured to operate according to a new air interface (e.g., other than an orthogonal frequency division multiple access (orthogonal frequency divisional multiple access, OFDMA) -based air interface) or a fixed transport layer (e.g., other than IP). NR may utilize OFDM with Cyclic Prefix (CP) on uplink and downlink and may include support for half-duplex (half-duplex) operation using time division duplex (time division duplexing, TDD). NR may include critical tasks for enhanced mobile broadband (enhanced mobile broadband, eMBB) services with wide bandwidth (e.g., above 80 MHz), millimeter wave (mmW) for high carrier frequencies (e.g., 60 GHz), mass MTC (emtc) for non-backward compatible MTC technologies, and/or ultra-reliable low latency communication (URLLC) services.

A single component carrier bandwidth of 100MHz may be supported. In one example, an NR Resource Block (RB) may span 12 subcarriers, with the subcarrier bandwidth being 60kHz over 0.25ms duration, or the bandwidth being 30kHz over 0.5ms duration (similarly, 50MHz BW is used for 15kHz SCS over 1ms duration). Each radio frame may include 10 subframes (10, 20, 40 or 80 NR slots) of length 10 ms. Each time slot may indicate a link direction (i.e., DL or UL) for data transmission, and the link direction of each time slot may be dynamically switched. Each slot may include DL/UL data and DL/UL control data. UL and DL slots for NR can be described in detail with reference to fig. 5 and 6 later.

The NR RAN may include a Central Unit (CU) and a Distributed Unit (DU). An NR BS (e.g., gNB, 5G node B, TRP, AP) can correspond to one or more BSs. The NR unit may be configured as an access cell (ACell) or a data only cell (DCell). For example, the RAN (e.g., a central unit or a distributed unit) may configure the cells. The DCell may be a cell for carrier aggregation or dual connectivity and may not be used for initial access, cell selection/reselection or handover. In some cases, the DCell may not transmit synchronization signals (synchronization signal, SS); in some cases, the DCell may transmit the SS. The NR BS may indicate the cell type to the UE by sending a downlink signal. Based on the cell type indication, the UE may communicate with the NR BS. For example, the UE may determine that the NR BS is cell-selected, accessed, handed over, and/or measured based on the indicated cell type.

Fig. 3 illustrates an example logical architecture of a distributed RAN 300 in accordance with aspects of the present application. The 5G access node 306 may include an access node controller (access node controller, ANC) 302. The ANC may be a CU of the distributed RAN. The backhaul interface to the next generation core network (next generation core network, NG-CN) 304 may terminate at the ANC. The backhaul interface to the neighboring next generation access node (next generation access node, NG-AN) 310 may terminate at the ANC. ANC may include one or more TRP 308 (which may also be referred to as BS, NR BS, nodeb, 5G NB, AP, or some other terminology). As described above, TRP may be used interchangeably with "cell".

TRP 308 may be a DU. TRP may be connected to one ANC (ANC 302) or multiple ANCs (not shown). For example, for RAN sharing, radio as a service (radio as a service, RAAS), and service specific ANC deployments, TRP may be connected to multiple ANCs. The TRP may include one or more antenna ports. The TRP may be configured to provide services to the UE either individually (e.g., dynamic selection) or jointly (e.g., joint transmission).

The local architecture of the distributed RAN 300 may be used to illustrate the definition of the frontau (frontau). An architecture may be defined that supports a forward-drive solution across different deployment types. For example, the architecture may be based on transport network capabilities (e.g., bandwidth, latency, and/or jitter). The architecture may share features and/or components with LTE. According to some aspects, NG-AN 310 may support dual connectivity with NR. NG-AN may share common preambles of LTE and NR.

The architecture may enable collaboration between TRP 308. For example, collaboration may be preset within and/or across TRPs via ANC 302. According to some aspects, an inter-TRP interface may not be needed/present.

According to some aspects, the dynamic configuration of the split logic functions may exist within the architecture of the distributed RAN 300. The PDCP, RLC, MAC protocol may be adaptively set at ANC or TRP.

Fig. 4 illustrates an example physical architecture of a distributed RAN 400 in accordance with aspects of the present application. The centralized core network unit (centralized core network unit, C-CU) 402 may have core network functionality. The C-CUs may be deployed centrally. The C-CU function may be split (e.g., to advanced wireless services (advanced wireless service, AWS)) to handle peak capacity. The centralized RAN unit (centralized RAN unit, C-RU) 404 may have one or more ANC functions. Alternatively, the C-RU may have core network functionality locally. The C-RU may have a distributed deployment. The C-RU may be closer to the network edge. The DU 406 may have one or more TRPs. The DUs may be located at the edge of the RF-enabled network.

Fig. 5 shows an example diagram 500 of a DL-centric time slot. The DL-centric time slot may comprise a control portion 502. The control portion 502 may exist at the beginning or beginning portion of a DL-centric time slot. The control portion 502 may include various scheduling information and/or control information corresponding to various portions of the DL-centric time slot. In some configurations, as shown in fig. 5, the control portion 502 may be a physical DL control channel (physical DL control channel, PDCCH). The DL-centric time slot may also include a DL data portion 504. The DL data portion 504 may sometimes be referred to as a payload (payload) of a DL-centric time slot. The DL data portion 504 may include communication resources for transmitting DL data from a scheduling entity (e.g., UE or BS) to a subordinate entity (e.g., UE). In some configurations, DL data portion 504 may be a physical DL shared channel (physical DL shared channel, PDSCH).

DL-centric time slots may also include a common UL portion 506. The common UL portion 506 may sometimes be referred to as a UL burst (burst), a common UL burst, and/or various other suitable terms. The common UL portion 506 may include feedback information corresponding to various other portions of the DL-centric time slot. For example, the common UL portion 506 may include feedback information corresponding to the control portion 502. Non-limiting examples of feedback information may include an ACK signal, a NACK signal, a HARQ indicator, and/or various other suitable types of information. The common UL portion 506 may include additional or alternative information, such as information related to random access channel (random access channel, RACH) procedures, scheduling requests (scheduling request, SR), and various other suitable types of information.

As illustrated in fig. 5, the end of DL data portion 504 may be separated in time from the beginning of common UL portion 506. Such time intervals may sometimes be referred to as gaps, guard periods, guard intervals, and/or various other suitable terms. And this separation provides time for a handoff from DL communication (e.g., a receive operation of a subordinate entity (e.g., UE)) to UL communication (e.g., a transmission of a subordinate entity (e.g., UE)). Those skilled in the art will appreciate that the foregoing is merely one example of DL-centric time slots, and that alternative structures with similar features may exist without departing from the spirit of the present invention.

Fig. 6 shows an example diagram 600 of UL-centric time slots. The UL-centric time slot may comprise a control portion 602. The control portion 602 may be present at the beginning or beginning of the UL-centric time slot. The control portion 602 in fig. 6 may be similar to the control portion 502 described above with reference to fig. 5. UL-centric time slots may also include UL data portion 604.UL data portion 604 may sometimes be referred to as the payload of a UL-centric time slot. The UL portion may refer to communication resources for transmitting UL data from a subordinate entity (e.g., UE) to a scheduling entity (e.g., UE or BS). In some configurations, the control portion 602 may be a PDCCH.

As illustrated in fig. 6, the end of the control portion 602 may be separated in time from the beginning of the UL data portion 604. Such time intervals may sometimes be referred to as gaps, guard periods, guard intervals, and/or various other suitable terms. And this separation provides time for switching from DL communication (e.g., a receiving operation of a scheduling entity) to UL communication (e.g., a transmission of a scheduling entity). UL-centric time slots may also include a common UL portion 606. The common UL portion 606 in fig. 6 may be similar to the common UL portion 506 described above with reference to fig. 5. The common UL portion 606 may additionally or alternatively include information regarding channel quality indicators (channel quality indicator, CQI), sounding reference signals (sounding reference signal, SRS), and various other suitable types. Those skilled in the art will appreciate that the foregoing is merely one example of UL-centric time slots, and that alternative structures with similar features may exist without departing from the spirit of the present invention.

In some cases, two or more subordinate entities (e.g., UEs) may communicate with each other using side-link signals. Real world applications for such side link communications may include public safety, proximity services, UE-to-network relay, vehicle-to-vehicle (V2V) communications, internet of everything (Internet of everything, ioE) communications, ioT communications, mission critical grids, and/or various other suitable applications. In general, a side link signal may refer to a signal transmitted from one subordinate entity (e.g., UE 1) to another subordinate entity (e.g., UE 2) without relaying the communication through a scheduling entity (e.g., UE or BS), even though the scheduling entity may be used for scheduling and/or control purposes. In some examples, the side-chain signals may be transmitted using licensed spectrum (as opposed to wireless local area networks that typically use unlicensed spectrum).

Fig. 7 is a diagram 700 illustrating downlink MIMO transmissions from a base station to a UE via one or more repeaters (repeaters). In this example, the base station 702 has 8 antennas 710-1, 710-2 … 710-8 and the ue 704 has 2 receive antennas 712-1, 712-2. In addition, a repeater 706-1 … 706-K is disposed between the base station 702 and the UE 704. In this example, K is 4. Each of the repeaters 706-1 … 706-K has two receive antennas 722-1, 722-2 and two transmit antennas 724-1, 724-2. In some configurations, the same antenna may be used as both the receive antenna and the transmit antenna. The 2 receive antennas 722-1, 722-2 of the repeater 706 receive antennas 710-1, 710-2 …, 710-8 over a channel 732 in band f ₁ An RF signal transmitted thereon. Repeater 706 is in band f ₂ The RF signal is transmitted via the 2 transmit antennas 724-1, 724-2. The 2 receive antennas 712-1, 712-2 of the UE 704 are in band f ₂ The upper receiving repeater 706 transmits RF signals over a channel 734.

Fig. 8 is a diagram 800 illustrating downlink transmission timing from a base station to a UE via one or more repeaters. The base station 702 transmits RF signals on a first carrier frequency in time slots 810-0, 810-1, 810-2, etc. via antennas 710-1, 710-2, …, 710-8. Relay device706-1 … -K receives RF signals of a first carrier frequency in time slots 820-0, 820-1, 820-2, etc. As described below, slots 810-0, 810-1, 810-2, etc. and slots 820-0, 820-1, 820-2, etc. correspond to a first subcarrier spacing (SCS ₁ ) Each occupying one TTI ₁ Spacing. The repeater 706-1 … 706-K converts the first set of baseband signals carried on the RF signals of the first carrier frequency to obtain a second set of baseband signals and transmits the second set of baseband signals over the RF signals of the second carrier frequency in time slots 830-0, …,830-q, time slots 831-0, …,831-q and 832-0, …,832-q, etc. As described below, the 830-0, …,830-q isochronous signal corresponds to the second subcarrier spacing (SCS ₂ For example 120 kHz), each occupying one TTI ₂ Spacing. In this example, q is 3.

In this example, the repeater 706-1 … 706-K receives an RF signal in time slot 820-0. Repeater 706-1 transmits its RF signal in slot 830-0; repeater 706-2 transmits its RF signal in slot 830-1; repeater 706-3 transmits its RF signal in slot 830-2; repeater 706-4 transmits its RF signal in time slot 830-3.

Phase tracking (phase tracking) is a key aspect in FR2 systems because it helps to solve the phase noise problem due to the unique RF characteristics of millimeter wave frequencies. In these systems, phase noise can cause common phase errors (common phase error, CPE) between symbols, resulting in reduced system performance. To address this problem, NR introduces a phase tracking reference signal (phase tracking reference signal, PT-RS) that allows tracking and estimating the phase rotation between symbols along the time domain.

PT-RS is particularly important in systems that forward signals between two different frequency ranges, such as FR1 and FR 2. In FR1 (e.g., f ₁ ) The base station 702 does not need to transmit PT-RS because the phase noise problem is less severe. However, when the signal is forwarded to FR2 (e.g., f ₂ ) Phase noise becomes a significant problem when PT-RS is needed to estimate and compensate for CPE.

In this example, the base station 702 can transmit PT-RS in this frequency range even though PT-RS is not needed in FR 1. When a signal from the base station 702 is forwarded to the UE 704 in FR2 through the repeaters 706-1 to 706-4, the PT-RS is included in the signal, thereby allowing the UE 704 to estimate CPE caused by the forwarding process. In addition, the UE 704 knows the requirement so that the phase error can be accurately estimated.

Fig. 9 is a diagram 900 illustrating physical resource blocks (physical resource block, PRBs) 910 transmitted by a base station 702 in a slot. The slot contains PDCCH 942, PDCCH demodulation reference signal (demodulation reference signal, DM-RS) 944, PDSCH 952, PDSCH DM-RS 954, and PDSCH PT-RS 956. In this example, the RE 912 carries a PDSCH PT-RS 956, which transmits every two symbols in the time domain.

A second time-frequency resource (e.g., f in FR 2) may be allocated for local communication between the UE 704 and the relay 706-1 … 706-K ₂ ). PT-RS 956 may be included in the RF signal from the base station 702 to help the UE 704 compensate at f ₂ CPE present in the transmission. The PT-RS 956 from the base station 702 may all come from one port. When the UE 704 starts to communicate locally with the repeater 706-1 … 706-K and obtains a baseband signal from the RF signal, the UE 704 may determine and compensate for the CPE by means of the PT-RS 956.

The channel response between a transmitter (e.g., base station 702) and a receiver (e.g., UE 704) on subcarrier 1 in OFDM symbol m is denoted as h _l，m . Based on the DM-RS measurements of the receiver in OFDM symbol d containing DM-RS, the estimated channel can be expressed as

Wherein h is _l,d Is the true channel frequency response of subcarrier l and symbol d, n _1,d Is the received noiseIs the phase rotation in symbol d produced by the CPE effect.

Similarly, based on PT-RS measurements of subcarriers/in OFDM symbol q containing PT-RS at the receiver, the estimated channel can be expressed as

Wherein the method comprises the steps ofIs the phase rotation in symbol q produced by the CPE effect.

In this example, symbol 2 contains DM-RS, so d=2. Wherein in OFDM symbol q where PT-RS is present, the estimation of CPE is given by

Wherein N is _PTRS Is the number of subcarriers scheduled with PT-RS, P is the index set of subcarriers scheduled with PT-RS, and arg (·) is the argument function (argument function) that returns the phase angle of the complex number.

The equation calculates an average phase difference between an estimated channel based on PT-RS measurement and an estimated channel based on DM-RS measurement of all subcarriers scheduled with PT-RS. In this way, the phase rotation caused by CPE in the received signal can be estimated.

For those OFDM symbols that do not contain PT-RS, the estimated phase of the symbol containing PT-RS may be rotatedInterpolation (interpolation) is performed to estimate the corresponding phase rotations produced by the CPE.

Accordingly, CPE in an OFDM symbol may be compensated based on the phase rotation to improve system performance. For example, by multiplying by a corresponding factorTo compensate for CPE.

Thus, using the above equation, CPE in OFDM symbol q including PT-RS can be estimated. In this example, symbol 4, symbol 6, symbol 8, symbol 10, and symbol 12 contain PT-RS, and CPE in these symbols can be estimated by using this equation. CPE in other symbols (e.g., symbol 3, symbol 5, symbol 7, symbol 9, symbol 11, and symbol 13) may interpolate based on these estimates.

In addition, the base station 702 transmits PT-RS configuration to the UE 704. Based on the PT-RS configuration, the UE 704 may determine the time/frequency location and value of the PT-RS 956. Base station 702 may be at f ₁ PT-RS 956 is sent from a port. At f ₁ Upon receipt of the PT-RS 956, the repeater 706-1 … 706-K forwards the PT-RS 956 to the UE 704 in a TDM manner. I.e. each relay in a different TTI ₂ PT-RS 956 is transmitted in an interval (e.g., one of slots 830-0, …, 830-q). Thus, even if PT-RS from the same port is used on all repeater-to-UE links, the UE 704 is in one TTI ₂ PT-RS 956 transmitted from at most one relay is received in the interval. Thus, the UE 704 may be based on the corresponding TTI without receiving any interference from the remaining relays ₂ PT-RS 956 received from a given repeater in an interval to estimate/compensate for CPE.

Fig. 10 is a diagram 1000 illustrating uplink MIMO transmission from a UE to a base station via one or more repeaters. In this example, the UE 704 has 2 transmit antennas 714-1, 714-2 and the base station 702 has 8 antennas 710-1, 710-2 … 710-8. In addition, a repeater 706-1 … 706-K is disposed between the UE 704 and the base station 702. In this example, K is 4. Each of the repeaters 706-1 … 706-K has two receive antennas 722-1, 722-2 and two transmit antennas 724-1, 724-2. In some configurations, the same antenna may be used as both the receive antenna and the transmit antenna. For example, the 2 receive antennas 722-1, 722-2 of repeater 706-1 are in band f via channel 1034 ₂ And receives RF signals transmitted by transmit antennas 714-1, 714-2 of UE 704. Repeater 706-1 is in band f through 2 transmit antennas 724-1, 724-2 ₁ And transmits RF signals. Antennas 710-1, 710-2 …, 710-8 of base station 702 are in band f ₁ And upper receiving repeater 706-1 transmits RF signals over channel 1032.

Fig. 11 is a diagram illustrating an uplink from a UE to a base station via one or more repeatersSchematic diagram 1100 of the uplink timing. The UE 704 is in time slots f in 1110-0, 1110-1, …,1110-q, slots 1111-0, 1111-1, …,1111-q and 1112-0, 1112-1, …,1112-q, etc ₂ And transmits a signal. As described below, the 1110-0, …,1110-q isochronous signal corresponds to the second subcarrier spacing (SCS ₂ For example 120 kHz). In this example, q is 3. Repeater 706-1 … 706-K is at f in time slots 1130-0, 1130-1, 1130-2, etc ₁ And the upper forwarding signal.

Fig. 12 is a schematic diagram 1200 illustrating signal transformation at a repeater. Each of the repeaters 706-1 … 706-K has a receive antenna 724-1, 724-2 in the uplink direction. Each receive antenna uses a respective receive chain 1250 to process RF signals received by the receive antenna. Taking the receiving antenna 722-1 of the repeater 706-1 as an example, the FFT component 1251 of the receiving antenna 724-1 has a size N ₂ . The down-converter 1256 receives the analog time domain signal and the analog-to-digital converter 1255 (abbreviated a/D in the figure) converts the analog signal to digital form and sends it to the conversion component 1254. The filtered digital samples from the conversion component 1254 pass through a downsampling (downsampling) block, if necessary, to convert the data rate of the digital sample stream to match the FFT size N ₁ . Accordingly, the position of the OFDM symbol may be determined in the down-converted digital samples. When digital samples within an OFDM symbol are found, CP removal component 1253 removes the CP used to prevent inter-symbol interference (inter-symbol interference, ISI). Serial-to-parallel component (abbreviated S/P) 1252 stores N ₂ The data samples are grouped into input vectors for FFT assembly 1251. FFT component 1251 outputs N ₂ Each modulation symbol1220, which is derived from the RF signal received at the receive antenna 724-1 of the repeater 706-1. In addition, have SCS ₂ N of (2) ₂ N is carried on sub-carriers 1210 ₂ Modulation symbol->1220. N received at the ith antenna of repeater 706-1 ₂ The modulation symbols are tabulatedShown as +.>k is a group index of modulation symbols carried on the kth OFDM symbol, and i is an index of an antenna port.

Further, each of the repeaters 706-1 … 706-K has a transmit antenna 722-1, 722-2 in the uplink direction, and a corresponding transmit chain 1260 is used to generate RF signals to be transmitted through each transmit antenna. Further, each transmit chain 1260 corresponds to a respective receive chain 1250. As described below, the modulation symbols received through the receiving antennas of the repeater are retransmitted through the corresponding transmitting antennas.

The transmit chain 1260 uses a transmit chain with SCS ₁ N of (2) ₁ Subcarriers 1230.IFFT component 1261 uses N ₁ With a point and N ₁ Input/output. Repeater 706-1 is configured with a predetermined rule that will N of FFT component 1251 ₂ The outputs are mapped to N of IFFT components 1261 ₁ An input.

More specifically, repeater 706-1 will be the kth group N ₁ Modulation symbol m _k,1 1240 for N ₁ Subcarriers 1230 to obtain corresponding OFDM symbols. Carry N ₁ Modulation symbol m _k,1 1240N ₁ Sub-carriers 1230 are transmitted to a carrier having N ₁ And input IFFT components 1261. N output from IFFT component 1261 ₁ The digital samples are considered to be time series and sent to a parallel-to-series component 1262 (abbreviated P/S in the figure) to form a time domain signal. CP insertion component 1263 receives the time domain signal and adds a cyclic prefix to produce a span corresponding to SCS ₂ Time domain signal of OFDM symbol B of (B). The resulting time domain signal is in digital form and may be processed by a conversion component 1264 that includes a rate converter and/or filter to achieve a desired sample rate. The converted time domain signal in digital form is sent to a digital-to-analog converter 1265 (abbreviated as D/a in the figure), and the digital-to-analog converter 1265 generates an analog time domain signal accordingly. The up-converter 1266 then receives the analog time domain signal and combines the analog time domain signal with the first carrier frequency f ₁ Mix to generate an RF signal. RF signalThe number is transmitted through the transmit antenna 722-1 of the repeater 706-1. In particular, the first carrier frequency of the RF signal transmitted from repeater 706-1 … 706-K may be FR1.

Fig. 13 is a diagram 1300 illustrating PRBs 1310 transmitted by a UE 704 in a slot. The slot contains PUSCH 1352, PUSCH DM-RS 1354 and PUSCH PT-RS 1356. In this example, RE 1312 carries a PUSCH PT-RS 1356, and PUSCH PT-RS 1356 is transmitted in every two symbols in the time domain.

In a first technique, CPE is estimated by the base station 702. A corresponding PT-RS port at the UE 704 is assigned to each of the repeaters 706-1 … 706-K. Accordingly, the base station 702 may individually estimate CPEs of links from the UE 704 to a specific repeater and to the base station 702 based on PT-RSs transmitted by PT-RS ports allocated to the specific repeater. In this example, UE 704 is at f ₂ PT-RS is transmitted from K ports. More specifically, the UE 704 is in the first TTI ₂ PT-RS are sent from the first port to the repeater 706-1 in an interval (e.g., slot 1110-0). Subsequently, the UE 704 is in the ith TTI ₂ PT-RSs are transmitted from the i-th port to the i-th repeater in an interval (e.g., slot 1110-i). In the subsequent TTI ₁ In the interval (e.g., time slot 1130-0), the repeater 706-1 … 706-K forwards the received PT-RSs of the K ports to the base station 702. The base station can thus distinguish between the same TTI based on PT-RS ports ₁ PT-RSs received in the interval (e.g., slot 1130-0) but forwarded by different repeaters. Similar to what is described above with respect to downlink CPEs, the base station 702 may separately determine the CPEs of the links through each repeater based on the PT-RS associated with that repeater. The base station 702 may inform the UE 704 of the respective PT-RS configuration for each of the repeaters 706-1 … 706-K to enable the UE 704 to send PT-RS using the appropriate configuration for each repeater link. By performing this first technique, the base station 702 may mitigate the effect of the CPE on transmissions between the UE 704 and the base station 702 through different repeaters. The overall performance and link quality of the system can be improved by accurate estimation of the CPE of the respective repeater paths.

Taking repeater 706-1 as an example, PUSCH PT-RS 1356 in the q-th OFDM symbol of slot 1140 and PUSCH DM-RS 1354 in OFDM symbol 2, which is known to base station 702. Using the following formulas described above,

base station 702 can estimate phase rotation phi of CPE of the qth OFDM symbol in slot 1140 _q . For those OFDM symbols that do not contain PT-RS, the estimated phase rotation in the symbol that contains PT-RS can be usedInterpolation is performed to estimate the corresponding phase rotations produced by the CPE. In time slot 1140, base station 702 receives the signals transmitted by each of the repeaters 706-1 … 706-K. The base station 702 may distinguish between reference signals forwarded by different repeaters based on DM-RS ports of the UE 704 associated with the signals. Each of the repeaters 706-1 … 706-K forwards signals from the unique DM-RS port of the UE 704 to the base station 702.

After obtaining the signal forwarded by the particular repeater in OFDM symbol q, the base station 702 accordingly compensates for the CPE for the signal on the RE carrying the DM-RS port to obtain a channel response without CPE. In this process, the base station 702 compensates for CPE introduced in the link between the UE 704 and the base station 702 through the particular repeater. In other words, the base station 702 may be based on an estimated value obtained from the previously described equationTo compensate for phase rotations associated with the respective repeater links. To perform this compensation, the base station 702 applies an inverse phase rotation +_for each repeater link to the received signal>Thereby mitigating the effects of CPE. This process allows the base station 702 to obtain more accurate channel information, resulting in improved overall system performance and enhanced link quality. The base station may then recover based on the signal received on the second frequency, the estimated channel response, and the estimated CPEData signals transmitted by the UE.

In the second technique, each repeater 706-1 … 706-K is at f ₁ Compensating for the difference f between the UE 704 and the respective repeater 706-1 … 706-K before forwarding the received RF signal to the base station 702 ₂ CPE present in high frequency transmissions. The UE 704 may use the shared PT-RS for f ₂ All UEs on (e.g., 28GHz in FR 2) to repeater links. These PT-RSs may be sent from the same port. This allows each repeater to estimate CPE in the q-th OFDM symbol of the corresponding slot of the plurality of slots 1120-0 through 1120-3 according to the following equation described above:

by performing this second compensation technique, each repeater 706-1 … 706-K can individually estimate and compensate for CPE associated with their respective UE-to-repeater links. This process enables the repeater to forward the compensated signal to the base station 702, thereby reducing the impact of the CPE on overall system performance, improving the link quality between the UE 704, the repeater and the base station 702.

To achieve this compensation, each repeater may rotate the reverse phaseApplied to the received signal, whereRepresenting the estimated phase rotation for CPE of the q-th OFDM symbol in the particular slot allocated to the repeater. When compensating for CPE, each repeater is at f ₁ The compensated signal is forwarded up to the base station 702. For example, the ith receive antenna of repeater 1106 receives signal +.>Applying an anti-phase rotation to the signal to obtain a compensated signal +.>As described above, the compensated signal +. >Then mapped to m _k,i . Subsequently, the ith transmit antenna of repeater 706-1 is at TTI ₁ Transmitting m to base station 702 in an interval (e.g., time slot 1130-0) _k,i 。

With this backoff technique, the repeaters 706-1 to 706-K are aware of the PT-RS configuration, which may be signaled by the base station 702 or signaled by the UE 704.

Upon receiving the compensated RF signal from the repeater 706-1 … 706-K, the base station 702 can then utilize the compensated signal to accurately process and decode the received information. In this way, the second compensation technique reduces the impact of the CPE on overall system performance, enhancing the link quality between the UE 704 and the base station 702 via the repeater.

Fig. 14 is a flow chart 1400 of a method (process) for downlink CPE estimation and compensation. The method may be performed by a UE. In operation 1402, the UE receives a PT-RS configuration from a base station. The PT-RS configuration includes information on time and frequency positions and values of the PT-RS.

In operation 1404, the UE receives a second carrier frequency (f ₂ ) And a second baseband signal carried thereon. The second baseband signal carries the data signal transmitted by the base station and is based on the first carrier frequency (f ₁ ) And the first baseband signal carried on the carrier is obtained. First carrier frequency (f ₁ ) Can be in a first frequency range FR1, while a second carrier frequency (f ₂ ) May be in the second frequency range FR 2.

In operation 1406, the UE estimates CPE in the first set of OFDM symbols based on the PT-RS in the received second baseband signal. PT-RS is transmitted by the base station at a first carrier frequency (f ₁ ) And transmitted over a second carrier frequency (f by at least one repeater ₂ ) And forwarding upwards to the UE. In some configurations, estimating the channel based on PT-RS measurements in the first set of OFDM symbols and based onCPE is estimated using phase differences between estimated channels of DM-RS measurements in a second set of OFDM symbols of PT-RS scheduled subcarriers.

In operation 1408, the UE estimates CPE of an OFDM symbol that does not contain a PT-RS by interpolating the estimated CPE of the OFDM symbol that contains the PT-RS. In addition, in operation 1410, the UE receives PT-RSs forwarded by different ones of the at least one relay in different TTIs.

Finally, in operation 1412, the UE detects a data signal based on the received second baseband signal and the estimated CPE in the first set of OFDM symbols. In some configurations, the received second baseband signal is compensated for the estimated CPE by applying an inverse phase rotation corresponding to the estimated CPE to the received second baseband signal.

Fig. 15 is a flow chart 1500 of a method (process) for uplink CPE estimation and compensation. The method may be performed by a base station. In operation 1502, the base station allocates a corresponding PT-RS port to each of at least one repeater. In operation 1504, the base station transmits a PT-RS configuration to the UE, wherein the PT-RS configuration is for each of the at least one repeater and includes an allocated PT-RS port.

In operation 1506, the base station receives a first carrier frequency (f ₁ ) A first baseband signal carried thereon. The first baseband signal is based on a second carrier frequency (f ₂ ) And the second baseband signal carried on the carrier signal. First carrier frequency (f ₁ ) Can be in a first frequency range FR1, while a second carrier frequency (f ₂ ) May be in the second frequency range FR 2.

In operation 1508, the base station distinguishes the first baseband signal forwarded by the different repeater based on the DM-RS port of the UE associated with the first baseband signal. Each of the at least one repeater forwards a signal from a unique DM-RS port of the UE. During operation 1510, the base station receives a PT-RS transmitted from the UE through a repeater according to a PT-RS configuration for each of at least one repeater.

In operation 1512, the base station based on the received first basePT-RS in the band signal associated with each of the at least one repeater to estimate CPE in the first set of OFDM symbols for a respective link between the UE and the base station over the repeater. PT-RS is transmitted by the UE at the second carrier frequency (f ₂ ) And transmitted over a first carrier frequency (f by a repeater ₁ ) And forwarding upwards to the base station. In some configurations, CPEs of a respective link by each repeater are estimated based on a phase difference between an estimated channel of the respective link based on PT-RS measurements in a first set of OFDM symbols and an estimated channel of the respective link based on DM-RS measurements in a second set of OFDM symbols of subcarriers scheduled with PT-RS.

In operation 1514, the base station estimates CPE of a corresponding link in an OFDM symbol that does not contain PT-RS by interpolating the estimated CPE of the corresponding link in the OFDM symbol that contains PT-RS. Subsequently, in operation 1516, the base station recovers the data signal transmitted by the UE based on the first baseband signal received from each repeater and the estimated CPE associated with the corresponding link between the UE and the base station through the repeater. In some configurations, the first baseband signals received from the repeaters are compensated for the estimated CPE associated with the respective link through the repeater by applying an inverse phase rotation to the first baseband signals received from the repeaters.

Fig. 16 is a flow chart 1600 of another method (process) for uplink CPE estimation and compensation. The method may be performed by a wireless device (e.g., repeater 706-1). In operation 1602, the wireless device determines that a first time slot of a set of time slots is allocated to the wireless device to receive a second baseband signal from the UE, while other time slots of the set of time slots are allocated to other wireless devices to receive the second baseband signal from the UE.

In operation 1604, the wireless device receives a PT-RS configuration from a base station or UE. The PT-RS configuration includes information about time and frequency positions and values of the PT-RS included in the second baseband signal. In operation 1606, the wireless device receives a signal from the UE at a second carrier frequency (f ₂ ) And a second baseband signal transmitted thereon.

In operation 1608, the wireless device estimates CPE in the first set of OFDM symbols based on the PT-RS in the received second baseband signal. The CPE may be estimated from a phase difference between an estimated channel based on PT-RS measurements in a first set of OFDM symbols and an estimated channel based on DM-RS measurements in a second set of OFDM symbols of subcarriers scheduled with PT-RS. This is an optional feature that may improve the accuracy of the CPE estimation process.

In operation 1610, the wireless device estimates CPE of an OFDM symbol that does not include a PT-RS by interpolating the estimated CPE of the OFDM symbol that includes the PT-RS. In operation 1612, the wireless device compensates the received second baseband signal for the estimated CPE in the first set of OFDM symbols. The compensation involves applying an inverse phase rotation corresponding to the estimated CPE to the received second baseband signal. In operation 1614, the wireless device maps the compensated second baseband signal to the first baseband signal to transmit at a first carrier frequency (f ₁ ) And sending the uplink signal to the base station.

Fig. 17 is a schematic diagram 1700 illustrating a hardware implementation of a device 1702 employing a processing system 1714. In one configuration, the device 1702 may be a UE (e.g., UE 704). In another configuration, the device 1702 may be a repeater (e.g., repeater 706-1). The processing system 1714 may be implemented with a bus architecture, represented generally by the bus 1724. The bus 1724 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 1714 and the overall design constraints. The bus 1724 links together various circuits including one or more processors and/or hardware, such as the receive component 1764, the transmit component 1770, the CPE estimation component 1776, the CPE compensation component 1778, and the computer-readable medium/memory 1706. Bus 1724 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits.

The processing system 1714 may be coupled to the transceiver 1710, which may be one or more of the transceivers 254. The transceiver 1710 is coupled to one or more antennas 1720, which antennas 1720 may be a communication antenna 252.

The transceiver 1710 provides a means for communicating with various other apparatus over a transmission medium. The transceiver 1710 receives a signal from one or more antennas 1720, extracts information from the received signal, and provides the extracted information to the processing system 1714, and in particular to the receiving component 1764. In addition, the transceiver 1710 receives information from the processing system 1714, and in particular the transmission component 1770, and generates a signal to one or more antennas 1720 based on the received information.

The processing system 1714 includes one or more processors 1704 coupled to a computer-readable medium/memory 1706. The one or more processors 1704 are responsible for general processing, including the execution of software stored on the computer-readable medium/memory 1706. The software, when executed by the one or more processors 1704, causes the processing system 1714 to perform the various functions described supra for any particular apparatus. The computer-readable medium/memory 1706 may also be used for storing data that is manipulated by the one or more processors 1704 when executing software. The processing system 1714 further includes at least one of a receiving component 1764, a transmitting component 1770, a CPE estimation component 1776, and a CPE compensation component 1778. These components may be software components running in the one or more processors 1704, retained/stored in computer-readable media/memory 1706, one or more hardware components coupled to the one or more processors 1704, or some combination thereof. The processing system 1714 may be a component of the UE 250 and may include the memory 260 and/or at least one of the TX processor 268, the RX processor 256, and the communication processor 259.

In a configuration as a UE, the apparatus 1702 for wireless communication includes means for performing various operations/processes of the UE (refer to fig. 14). In the configuration as a repeater, the apparatus 1702 for wireless communication includes means for performing various operations/processes of a wireless device (refer to fig. 16). The apparatus may be one or more of the above-described components of the device 1702 and/or the processing system 1714 of the device 1702 configured to perform the functions described by the apparatus.

As described above, processing system 1714 may include TX processor 268, RX processor 256, and communications processor 259. As such, in one configuration, the means may be TX processor 268, RX processor 256, and communications processor 259 configured to perform the functions described by the means.

Fig. 18 is a schematic diagram 1800 illustrating a hardware implementation of a device 1802 employing a processing system 1814. Device 1802 may be a base station (e.g., base station 702). The processing system 1814 may be implemented with a bus architecture, represented generally by the bus 1824. The bus 1824 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 1814 and the overall design constraints. The bus 1824 links together various circuits including one or more processors and/or hardware components, such as the one or more processors 1804, the receive component 1864, the transmit component 1870, the CPE estimation component 1876, and the CPE compensation component 1878, as well as the computer-readable medium/memory 1806. The bus 1824 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits.

The processing system 1814 may be coupled to a transceiver 1810, which may be one or more transceivers 254. The transceiver 1810 is coupled to one or more antennas 1820, which 1820 may be a communications antenna 220.

The transceiver 1810 provides a means for communicating with various other apparatus over a transmission medium. The transceiver 1810 receives signals from the one or more antennas 1820, extracts information from the received signals, and provides the extracted information to the processing system 1814, and in particular to the receiving component 1864. In addition, the transceiver 1810 receives information from the processing system 1814, and in particular, the transmission component 1870, and generates signals to one or more antennas 1820 based on the received information.

The processing system 1814 includes one or more processors 1804 coupled to a computer-readable medium/memory 1806. The one or more processors 1804 are responsible for general processing, including the execution of software stored on the computer-readable medium/memory 1806. The software, when executed by the one or more processors 1804, causes the processing system 1814 to perform the various functions described supra for any particular apparatus. The computer-readable medium/memory 1806 may also be used for storing data that is manipulated by the one or more processors 1804 when executing software. The processing system 1814 further includes at least one of a receive component 1864, a transmit component 1870, a CPE compensation component 1878, and a CPE estimation component 1876. These components may be software components running in the one or more processors 1804, retained/stored in computer-readable media/memory 1806, one or more hardware components coupled to the one or more processors 1804, or some combination thereof. The processing system 1814 may be a component of the base station 210 and may include the memory 276 and/or at least one of the TX processor 216, the rx processor 270, and the controller/processor 275.

In one configuration, the device 1802 for wireless communication includes means for performing the various operations of fig. 15. The apparatus may be one or more of the above-described components of the device 1802 and/or the processing system 1814 of the device 1802 configured to perform the functions described by the apparatus.

As described above, the processing system 1814 may include the TX processor 216, the RX processor 270, and the controller/processor 275. As such, in one configuration, the means may be the TX processor 216, the RX processor 270, and the controller/processor 275 configured to perform the functions described by the means.

It should be understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is only for exemplary illustration. Based on design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Furthermore, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

The above description may enable one of ordinary skill in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Accordingly, the claims are not intended to be limited to the aspects shown herein but are to be accorded the full scope of the language claims. Where elements are referred to in the singular, unless explicitly stated to the contrary, it is not intended to mean "one and only one" but rather "one or more". The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. The term "some" means one or more unless specifically stated otherwise. Combinations such as "at least one of A, B or C", "one or more of A, B or C", "at least one of A, B and C", "one or more of A, B and C", and "A, B, C or any combination thereof" include any combination of A, B and/or C, and may include a plurality of a, a plurality of B, or a plurality of C. Specifically, for example, a combination of "at least one of A, B or C", "one or more of A, B or C", "at least one of A, B and C", "one or more of A, B and C" and "A, B, C or any combination thereof" may be a alone, B alone, C, A and B, A and C, B and C, or a and B and C, wherein any such combination may comprise one or more members of A, B or C. All structural and functional equivalents to the elements of the various aspects described throughout this document (that are known to those of ordinary skill in the art or that later become known) are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words "module," mechanism, "" element, "" means, "and the like may not be substitutes for the word" means. Thus, unless the phrase "means for …" is used to expressly state the element, the claim elements should not be construed as means-plus-function.

Although the present invention has been described in connection with certain specific embodiments for instructional purposes, the present invention is not limited thereto. Accordingly, various modifications, adaptations, and combinations of the various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.

Claims (22)

1. A wireless communication method for a user equipment, comprising:

receiving a second baseband signal carried on a second carrier frequency transmitted by at least one repeater, wherein the second baseband signal carries a data signal transmitted by a base station and is derived from a first baseband signal carried on a first carrier frequency transmitted by the base station;

estimating a common phase error, CPE, in a first set of orthogonal frequency division multiplexing, OFDM, symbols based on a phase tracking reference signal, PT-RS, included in the received second baseband signal, wherein the PT-RS is transmitted by the base station on the first carrier frequency and forwarded to the user equipment, UE, on the second carrier frequency by the at least one repeater; and

the data signal is detected based on the received second baseband signal and the estimated CPE in the first set of OFDM symbols.

2. The wireless communication method of claim 1, wherein the CPE is estimated based on a phase difference between an estimated channel measured by PT-RS in the first set of OFDM symbols and an estimated channel measured by demodulation reference signal DM-RS in a second set of OFDM symbols of subcarriers scheduled with PT-RS.

3. The wireless communication method according to claim 1, wherein the received second baseband signal is compensated for the estimated CPE by applying an inverse phase rotation corresponding to the estimated CPE to the received second baseband signal.

4. The wireless communication method according to claim 1, further comprising:

the estimated CPEs of the OFDM symbols containing PT-RS are interpolated to estimate CPEs of the OFDM symbols not containing PT-RS.

5. The wireless communication method according to claim 1, further comprising:

PT-RSs forwarded by different ones of the at least one relay are received in different transmission time intervals TTIs.

6. The wireless communication method according to claim 1, further comprising:

a PT-RS configuration is received from the base station, wherein the PT-RS configuration includes information about time and frequency locations and values of the PT-RS.

7. The wireless communication method according to claim 1, wherein the first carrier frequency is in a first frequency range FR1 and the second carrier frequency is in a second frequency range FR 2.

8. A wireless communication method for a base station, comprising:

the base station receives a first baseband signal carried on a first carrier frequency sent by at least one repeater, wherein the first baseband signal is obtained according to a second baseband signal carrying a data signal on a second carrier frequency sent by User Equipment (UE);

the base station estimating a common phase error, CPE, in a first set of orthogonal frequency division multiplexing, OFDM, symbols for a respective link between the UE and the base station over the repeater based on phase tracking reference signals, PT-RS, associated with each of the at least one repeater in the first baseband signal, wherein the PT-RS is transmitted by the UE on the second carrier frequency and forwarded by the repeater to the base station on the first carrier frequency; and

the base station recovers the data signal carried by the second baseband signal based on the first baseband signal received from each repeater and an estimated CPE associated with a respective link between the UE and the base station over the repeater.

9. The wireless communication method according to claim 8, further comprising:

the base station allocates a corresponding PT-RS port to each of the at least one repeater;

transmitting a PT-RS configuration from the base station to the UE, wherein the PT-RS configuration is for each of the at least one repeater and includes an allocated PT-RS port; and

the base station receives, through the relay, the PT-RS transmitted from the UE according to a PT-RS configuration for each of the at least one relay.

10. The wireless communication method of claim 8, wherein CPE of a respective link of a subcarrier scheduled with PT-RS is estimated based on a phase difference between an estimated channel of the respective link measured by the PT-RS in the first set of OFDM symbols and an estimated channel of the respective link measured by a demodulation reference signal DM-RS in a second set of OFDM symbols based on the subcarrier.

11. The wireless communication method according to claim 8, further comprising:

the base station distinguishes the first baseband signal forwarded by different repeaters based on the DM-RS port of the UE associated with the first baseband signal, wherein each repeater of the at least one repeater forwards a signal from a unique DM-RS port of the UE.

12. The wireless communication method of claim 8, wherein the first baseband signals received from the repeaters are compensated for the estimated CPEs associated with the respective links through the repeaters by applying an inverse phase rotation to the first baseband signals received from the repeaters, the inverse phase rotation corresponding to the estimated CPEs associated with the respective links.

13. The method of claim 8, further comprising interpolating the estimated CPEs of the corresponding links in the OFDM symbols including the PT-RS to estimate the CPEs of the corresponding links in the OFDM symbols not including the PT-RS.

14. The wireless communication method of claim 8, wherein the first carrier frequency is in a first frequency range FR1 and the second carrier frequency is in a second frequency range FR 2.

15. A method of wireless communication for a wireless device, comprising:

receiving, by the wireless device, a second baseband signal from a user equipment UE transmitted on a second carrier frequency;

estimating a common phase error CPE in a first set of orthogonal frequency division multiplexing, OFDM, symbols based on a phase tracking reference signal PT-RS in the received second baseband signal;

Compensating the received second baseband signal for the estimated CPE in the first set of OFDM symbols; and

the compensated second baseband signal is mapped to the first baseband signal for transmission to the base station on the first carrier frequency.

16. The wireless communication method of claim 15, wherein the CPE is estimated based on a phase difference between an estimated channel measured by PT-RS in the first set of OFDM symbols and an estimated channel measured by demodulation reference signal DM-RS in a second set of OFDM symbols of subcarriers scheduled with PT-RS.

17. The wireless communication method of claim 15, wherein compensating the received second baseband signal comprises applying an inverse phase rotation corresponding to the estimated CPE to the received second baseband signal.

18. The method of claim 15, further comprising estimating CPEs of OFDM symbols not including PT-RS by interpolating the estimated CPEs of OFDM symbols including PT-RS.

19. The wireless communication method according to claim 15, further comprising:

a first time slot of a set of time slots is determined to be allocated to the wireless device to receive the second baseband signal from the UE, while other time slots of the set of time slots are allocated to other wireless devices to receive baseband signals from the UE.

20. The wireless communication method according to claim 15, further comprising:

the wireless device receives a PT-RS configuration from the base station or the UE, wherein the PT-RS configuration includes information about time and frequency locations and values of PT-RS included in the second baseband signal.

21. A user equipment comprising circuitry to:

receiving a second baseband signal carried on a second carrier frequency transmitted by at least one repeater, wherein the second baseband signal carries a data signal transmitted by a base station and is derived from a first baseband signal carried on a first carrier frequency transmitted by the base station;

estimating a common phase error, CPE, in a first set of orthogonal frequency division multiplexing, OFDM, symbols based on a phase tracking reference signal, PT-RS, included in the received second baseband signal, wherein the PT-RS is transmitted by the base station on the first carrier frequency and forwarded to the user equipment, UE, on the second carrier frequency by the at least one repeater; and

the data signal is detected based on the received second baseband signal and the estimated CPE in the first set of OFDM symbols.

22. A storage medium storing a program which, when executed, causes an apparatus to perform the steps of the wireless communication method of any one of claims 1-20.