WO2021128026A1

WO2021128026A1 - Information sending method, information receiving method and apparatus

Info

Publication number: WO2021128026A1
Application number: PCT/CN2019/128088
Authority: WO
Inventors: 余健; 郭志恒
Original assignee: 华为技术有限公司
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2021-07-01
Also published as: CN114846868A; WO2021128751A1

Abstract

Disclosed are an information sending method, an information receiving method and an apparatus, which are used to provide new feedback information to a network device to assist the network device in performing better uplink channel estimation. The information receiving method comprises: a network device sending configuration information of feedback information to a terminal device, wherein the configuration information of the feedback information instructs the terminal device to feed back the Doppler frequency offset of a downlink channel and/or the time delay of the downlink channel; and the terminal device receiving indication information of the Doppler frequency offset of the downlink channel and/or indication information of the time delay of the downlink channel from the terminal device. In this method, a terminal device can feed back the Doppler frequency offset of a downlink channel and/or the time delay of the downlink channel to a network device, so that the network device can perform uplink channel estimation by means of the correlation or reciprocity between an uplink channel and the downlink channel in conjunction with the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel, thereby ameliorating the problem in the prior art of uplink channel estimation performance being limited by the maximum uplink pilot density.

Description

Information sending method, receiving method and device

Technical field

This application relates to the field of communication technology, and in particular to an information sending method, receiving method and device.

Background technique

In scenarios such as channel state information (CSI) measurement and data demodulation, the base station needs to estimate the current channel based on the uplink pilot, that is, perform uplink channel estimation.

The performance of uplink channel estimation is closely related to the transmission period of the uplink pilot and the time-frequency density of the uplink pilot. The greater the time-frequency density of the uplink pilot, the better the uplink channel estimation performance. However, greater time-frequency density means higher pilot overhead, and uplink transmission time slots are limited, so higher uplink pilot overhead will affect the throughput and reduce the performance of uplink transmission. With a small time-frequency density, it is impossible to accurately estimate the uplink channel information.

It can be seen that the terminal equipment in the prior art only provides uplink pilots to the base station for uplink channel estimation, so that the uplink channel estimation performance is limited by the maximum uplink pilot density, and it is impossible to take into account both the uplink channel estimation performance and the uplink pilot overhead. .

Summary of the invention

This application provides an information sending method, receiving method, and device, which are used to provide new feedback information to network equipment to assist the network equipment in performing better uplink channel estimation.

In the first aspect, an embodiment of the present application provides an information receiving method, which can be applied to a network device, including: sending configuration information of feedback information to a terminal device, and the configuration information of the feedback information indicates how many downlink channels the terminal device feeds back. The Doppler frequency offset and/or the delay of the downlink channel; receiving indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the downlink channel delay from the terminal device.

In the embodiment of the present application, the configuration information of the feedback information may be sent to the terminal device through the network device to instruct the terminal device to feed back the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel. After the terminal device receives the configuration information of the feedback information , The indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the time delay of the downlink channel can be fed back to the network equipment. Compared with the prior art, the terminal equipment can provide Doppler frequency deviation indication information and/or the delay of the downlink channel to the network equipment, so that the network equipment can use the correlation or reciprocity between the uplink channel and the downlink channel, The uplink channel estimation is performed in combination with the indication information of the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel, thereby improving the technical problem that the uplink channel estimation performance in the prior art is limited by the maximum uplink pilot density.

In a possible design, the network device may perform uplink channel estimation based on the pilot signal, the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel.

In this embodiment, on the basis of the pilot signal, the network device also combines the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel to perform uplink channel estimation, which can improve the channel estimation under a given pilot density. The upper limit of performance, or under the condition of ensuring certain channel estimation performance, reduce pilot overhead, in addition, it can also well match the dynamic channel estimation requirements to achieve the purpose of improving uplink coverage and uplink capacity.

In a possible design, the configuration information of the feedback information may be downlink CSI configuration information.

In this way, the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the time delay of the downlink channel can be carried by the downlink CSI, and no additional signaling is needed to carry the indication information separately, which can save system overhead.

In a possible design, the configuration information of the feedback information may also be carried in radio resource control RRC signaling or medium access control MAC signaling.

In this way, it is possible to directly instruct the terminal equipment to feed back the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel without changing the original signaling configuration.

In a possible design, the Doppler frequency offset of the downlink channel may include: the Doppler frequency offset of each path of the downlink channel, and the Doppler frequency offset of all paths of the downlink channel. One or more of the maximum Doppler frequency deviation or the average Doppler frequency deviation of all paths of the downlink channel.

This embodiment provides multiple specific feedback forms of Doppler frequency offset, which can improve the flexibility of the solution.

In a possible design, the delay of the downlink channel may include: the delay of each path of the downlink channel, the maximum delay among the delays of all the paths of the downlink channel, or the delay of the downlink channel One or more of the average delay of all paths, etc.

This embodiment provides multiple specific feedback forms of the delay of the downlink channel, which can improve the flexibility of the solution.

In a possible design, the configuration information of the feedback information may also indicate the number of paths of the downlink channel fed back by the terminal device. Correspondingly, after sending the configuration information of the feedback information to the terminal device, the network device may also receive the path number of the downlink channel, the delay extension of the downlink channel, the Doppler extension of the downlink channel, and the delay extension of the downlink channel from the terminal device. Indication information of arrival angle and/or departure angle of each path.

In this embodiment, the terminal device provides more feedback information that is helpful for the network device to perform uplink channel estimation, which can further improve the flexibility and accuracy of the network device's uplink channel estimation.

In a possible design, the network equipment performs uplink channel estimation based on the pilot signal, the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel, and the specific methods for estimating the uplink channel include but are not limited to the following two :

Manner 1. The network equipment first performs channel estimation based on the pilot signal to generate the first channel estimation result; then, the first channel is calculated based on the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel. The estimation result is corrected, and the second channel estimation result is obtained as the uplink channel estimation result.

_{Manner 2. The network device first estimates the autocorrelation matrix R HH of} the uplink channel H according to the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel; and then calculates the autocorrelation matrix of the uplink channel H R _HH introduces the minimum mean square error MMSE algorithm to derive and solve the uplink channel H, and obtain the estimation result H _{mmse of the uplink channel H.}

This embodiment provides two methods for uplink channel estimation by combining pilot signals, Doppler frequency offset and/or downlink channel delay, both of which can improve the upper limit of channel estimation performance under a given pilot density. , Or under the condition that certain channel estimation performance is guaranteed, pilot overhead is reduced, and the flexibility of the scheme is improved.

In the second aspect, an embodiment of the present application provides an information sending method that can be applied to a terminal device. The method includes: receiving configuration information of feedback information from a network device, where the configuration information of the feedback information indicates how many downlink channels the terminal device feeds back. The Doppler frequency offset and/or the delay of the downlink channel; and the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the delay of the downlink channel is sent to the network device.

In a possible design, the configuration information of the feedback information may be downlink CSI configuration information, and the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the downlink channel delay may be carried by the downlink CSI. .

In a possible design, the configuration information of the feedback information may be carried in radio resource control RRC signaling or media access control MAC signaling.

In a possible design, the Doppler frequency offset of the downlink channel may include the Doppler frequency offset of each path of the downlink channel, and the largest Doppler frequency offset of all paths of the downlink channel. Doppler frequency offset; or one or more of the average Doppler frequency offset of all paths of the downlink channel.

In a possible design, the time delay of the downlink channel may include the time delay of each path of the downlink channel, the maximum time delay among the time delays of all the paths of the downlink channel, or all the time delays of the downlink channel. One or more of the average delay of the path.

In a possible design, the configuration information of the feedback information also indicates the number of paths for the terminal device to feed back the downlink channel; after receiving the configuration information of the feedback information from the network device, the terminal device may also send to the network device Indication information of the number of paths of the downlink channel.

In a third aspect, an embodiment of the present application provides an information receiving device, which may be a network device or a device in a network device. The device includes a sending unit for sending configuration information of feedback information to a terminal device, The configuration information of the feedback information indicates that the terminal device feeds back the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel; the receiving unit is configured to receive the Doppler frequency offset of the downlink channel from the terminal device And/or the time delay of the downlink channel.

In a possible design, the Doppler frequency offset of the downlink channel may include the Doppler frequency offset of each path of the downlink channel, and the largest Doppler frequency offset of all paths of the downlink channel. One or more of the Doppler frequency offset or the average Doppler frequency offset of all paths of the downlink channel.

In a possible design, the delay of the downlink channel may include: the delay of each path of the downlink channel, the maximum delay among the delays of all the paths of the downlink channel, or the delay of the downlink channel. One or more of the average delay of all paths, etc.

In a possible design, the configuration information of the feedback information may also indicate the number of paths of the downlink channel fed back by the terminal device; the receiving unit may also be used to receive an indication of the number of paths of the downlink channel from the terminal device information.

In a possible design, the device may further include: a processing unit configured to perform uplink channel estimation based on the pilot signal, the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel .

In a possible design, the processing unit is specifically configured to: perform channel estimation based on pilot signals to generate a first channel estimation result; and based on the Doppler frequency offset of the downlink channel and/or the time of the downlink channel The first channel estimation result is revised, and the second channel estimation result is obtained as the uplink channel estimation result.

_{In a possible design, the processing unit is specifically configured to: estimate the autocorrelation matrix R HH of the} uplink channel H according to the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel; The autocorrelation matrix R _HH of the uplink channel H is brought into the minimum mean square error MMSE algorithm to derive and solve the uplink channel H, and the estimation result H _{mmse of} the uplink channel H is obtained.

In a fourth aspect, an embodiment of the present application provides an information sending device, which may be a terminal device or a device in a terminal device. The device includes: a receiving unit for receiving configuration information of feedback information from a network device The configuration information of the feedback information indicates that the terminal device feeds back the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel; the sending unit is used to send an indication of the Doppler frequency offset of the downlink channel to the network device Information and/or indication information of the time delay of the downlink channel.

In a possible design, the configuration information of the feedback information may also indicate the number of paths of the downlink channel fed back by the terminal device; the sending unit may also be used to: send an indication of the number of paths of the downlink channel to the network device information.

In a fifth aspect, an embodiment of the present application provides an information receiving device, which may be a network device or a device in a network device. The device includes: a memory for storing a computer program; a processor for executing all the information. The computer program stored in the memory, so that the apparatus executes the method described in the first aspect or any possible design of the first aspect of the embodiments of the present application.

In a sixth aspect, an embodiment of the present application provides an information receiving device. The device may be a terminal device or a device in a terminal device. The device includes: a memory for storing a computer program; and a processor for executing all the information. The computer program stored in the memory, so that the apparatus executes the method described in the second aspect or any possible design of the second aspect of the embodiment of the present application.

In a seventh aspect, an embodiment of the present application provides an information receiving device. The device may be a network device or a device in a network device. The device includes a processor and a transceiver. Wherein, the processor is configured to support the apparatus to perform the corresponding function of the network device in the method described in the first aspect or any one of the possible designs of the first aspect of the embodiments of the present application. The transceiver is used to support communication between the network device and other devices (such as terminal devices). Among them, the transceiver may be an independent receiver, an independent transmitter, a transceiver with integrated transceiver functions, or an interface circuit.

In an eighth aspect, an embodiment of the present application provides an information sending device. The device may be a terminal device or a device in a terminal device. The device includes a processor and a transceiver. Wherein, the processor is configured to support the apparatus to perform the corresponding function of the terminal device in the method described in the second aspect or any possible design of the second aspect of the embodiment of the present application. The transceiver is used to support communication between the terminal device and other devices (such as network devices). Among them, the transceiver may be an independent receiver, an independent transmitter, a transceiver with integrated transceiver functions, or an interface circuit.

In a ninth aspect, an embodiment of the present application provides a computer-readable storage medium, including a program or instruction. When the program or instruction runs on a computer, it executes any one of the first aspect or the first aspect of the embodiment of the present application. One possible design method described in.

In a tenth aspect, an embodiment of the present application provides a computer-readable storage medium, including a program or instruction. When the program or instruction runs on a computer, it executes any one of the second aspect or the second aspect of the embodiment of the present application. One possible design method described in.

In an eleventh aspect, an embodiment of the present application provides a chip, which is coupled with a memory, and is used to read and execute program instructions stored in the memory to implement the first aspect or the first aspect of the embodiment of the present application. Any of the possible designs described in the method.

In a twelfth aspect, an embodiment of the present application provides a chip, which is coupled with a memory, and is used to read and execute program instructions stored in the memory to implement the second aspect or the second aspect of the embodiment of the present application. Any of the possible designs described in the method.

In a thirteenth aspect, an embodiment of the present invention provides a wireless communication system. The wireless communication system includes the network equipment and terminal equipment involved in the foregoing aspects.

Description of the drawings

Figure 1 is a schematic diagram of the flow of DMRS transmission;

FIG. 2 is a schematic diagram of a network architecture of a communication system provided by an embodiment of this application;

FIG. 3 is a flowchart of an information transmission method provided by an embodiment of this application;

FIG. 4 is a flowchart of a data demodulation method provided by an embodiment of this application;

FIG. 5 is a flowchart of a signal measurement method provided by an embodiment of this application;

FIG. 6 is a schematic structural diagram of an information receiving device provided by an embodiment of this application;

FIG. 7 is a schematic structural diagram of an information sending device provided by an embodiment of this application;

FIG. 8 is a schematic structural diagram of another information receiving device provided by an embodiment of this application;

FIG. 9 is a schematic structural diagram of another information sending device provided by an embodiment of this application;

FIG. 10 is a schematic structural diagram of another information receiving device provided by an embodiment of this application;

FIG. 11 is a schematic structural diagram of another information sending device provided by an embodiment of the application.

Detailed ways

In a wireless communication system, according to the different types of sending nodes and receiving nodes, communication can be divided into different types. Generally, sending information from a network device to a terminal device is called downlink (DL) communication, and sending information from a terminal device to a network device is called uplink (UL) communication.

In downlink communication, when a base station as a network device allocates time-frequency resources to a terminal device, in order to match changes in channel information and interference information between the base station and the terminal device, channel state information (CSI) needs to be measured. The measurement content mainly includes rank indicator (rank indicator, RI), precoding indicator (precoding matrix indicator, PMI), channel quality indicator (channel quality indicator, CQI), etc. In the CSI measurement process, the terminal equipment measures the channel quality at the current moment according to the reference signal (RS) sent by the base station, and then feeds back the measurement result to the base station.

In the fourth generation (4G) wireless communication system, terminal equipment can use cell-specific reference signal (CRS) and channel state information reference signal (channel state information reference signal, CSI-RS). Channel measurement. In the fifth generation (5G) wireless communication system, the new radio access technology (NR) system, terminal equipment can use the channel state information reference signal (CSI- RS) to perform CSI measurement. In addition, in NR, terminal equipment can also measure channel state information through synchronization signal/broadcast channel resource block (SS/PBCH block, SSB), tracking reference signal (tracking reference signal), etc., such as measuring channel multipath delay, Delay spread, Doppler frequency offset and other parameters.

In LTE and NR uplink transmission, a demodulation reference signal (DMRS) and a sounding reference signal (SRS) are defined. The SRS signal is used for CSI measurement, and the DMRS is used for physical uplink shared channel (PUSCH) data demodulation. When performing CSI measurement and data demodulation, it is necessary to first estimate the current channel based on the uplink pilot, that is, perform channel estimation. For ease of description, the uplink pilot frequency can also be called the pilot frequency. In the following description in this article, unless otherwise specified, the pilot frequency that appears refers to the uplink pilot frequency.

In the related art, the base station performs channel estimation based on the uplink pilot. Take the above DMRS transmission as an example, please refer to Figure 1. The DMRS transmission process includes:

S101. The base station configures the time-frequency position of the DMRS through RRC signaling, such as the number of symbols, symbol positions, and frequency domain density. For details, see the DMRS-UplinkConfig configuration information defined in the 3GPP TS 38.331 protocol.

S102. When the terminal device has data transmission, the base station schedules the uplink data. Specifically, the terminal device may be instructed about PUSCH transmission information through a downlink control indicator (DCI), where the PUSCH transmission information may include scheduled physical resource blocks (physical resource block, PRB) time-frequency resource location, modulation coding index (MCS), bandwidth indication, number of antenna ports, etc. For details, please refer to the DCI format 0_0 and DCI format 0- defined in the 3GPP TS 38.212 protocol. 1.

S103. The terminal device sends the uplink data and the DMRS according to the DMRS configuration information and the PUSCH scheduling information.

S104. The base station receives PUSCH data and DMRS sent by the terminal equipment, and performs channel estimation according to the PUSCH data and DMRS. The process is mainly divided into two steps: First, the base station estimates the channel at the location of the pilot based on the pilot in the DMRS; second, further estimates the channel information at the PUSCH data location based on the channel information at the pilot location. In the first step, the least square (LS) method or the minimum mean square error (MMSE) method can be used for estimation. In the second step, linear interpolation or other more complex methods can be used for estimation. Please refer to the embodiment for the specific algorithm flow. It should be noted that LS estimation is simple to implement, and its performance is generally lower than that of MMSE. But MMSE needs to know the statistical information of the channel and a priori information.

S105. The base station compensates the channel according to the estimated channel on the PUSCH data position, uses an equalization algorithm such as LS or MMSE to obtain the equalized data, and then performs operations such as deconstellation and decoding.

Based on the above description, the prior art only relies on pilot signals when performing uplink channel estimation, and the performance of uplink channel estimation is closely related to the transmission period of the pilot and the time-frequency density of the pilot. In order to ensure the uplink channel estimation performance, appropriate SRS and DMRS time-frequency density configurations need to be selected. For example, in the time domain, a DMRS can be configured with one symbol or a maximum of 4 symbols, and in the frequency domain, a configuration with a density of 4RE/PRB and a density of 6RE/PRB is also supported. But greater time-frequency density means higher pilot overhead. Therefore, in uplink channel estimation, channel estimation performance and pilot overhead need to be considered.

If the maximum time-frequency density is adopted, the pilot overhead will be very large. For example, when DMRS configures 4 symbols, its overhead is 28.6%. For a TDD system, the uplink transmission time slot itself is few. For example, when the downlink to uplink time slot ratio is 4:1, the uplink pilot overhead will seriously affect the throughput. If a smaller time-frequency density is used, the channel information, such as frequency offset and time offset, cannot be accurately obtained. In addition, the existing uplink channel estimation only relies on pilot estimation, and its performance is limited by the pilot density configured at the current moment. In general, the uplink channel estimation method in the prior art mainly has the following shortcomings:

1) When the channel estimation performance is improved by increasing the pilot density, the pilot overhead will be significantly enhanced. When the pilot density is maximum, the system performance may be limited by the accuracy of channel estimation, and the data cannot be demodulated correctly.

2) In the estimation, there is a lack of prior information of the channel, such as time delay, angle, Doppler frequency offset, etc. Therefore, even when the pilot frequency density is the largest, an accurate uplink channel estimation result may not be obtained.

3). When the pilot is sent aperiodicly, the statistical information of the channel cannot be well estimated, such as delay spread, angle spread, Doppler spread, etc.

4) The configuration of SRS and DMRS mainly depends on radio resource control (Radio Resource Control, RRC) signaling, and the time delay for changing the configuration will be large, usually on the order of tens of milliseconds, which cannot match the dynamic channel estimation requirements.

In order to solve one or more of the above technical problems, embodiments of the present application provide an information sending method, receiving method, and device. It can be applied to various wireless communication systems, such as the 4th Generation (4G), 4G systems including LTE systems, worldwide interoperability for microwave access (WiMAX) communication systems, and the 5th generation (5th generation) , 5G) systems, such as NR, and future communication systems, such as 6G systems. Of course, the technical solutions of the embodiments of the present application can also be applied to other communication systems, as long as the communication system has uplink and downlink communication links. Exemplarily, FIG. 2 is a schematic diagram of a network architecture of a communication system provided by an embodiment of the application. The communication system includes network equipment and terminal equipment. The network equipment can send downlink data to the terminal equipment, the terminal equipment can receive the downlink data sent by the network equipment, the terminal equipment can send the uplink data to the network equipment, and the network equipment can receive the data sent by the terminal equipment. Upstream data.

In the embodiment of the present application, the configuration information of the feedback information may be sent to the terminal device through the network device to instruct the terminal device to feed back the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel; after the terminal device receives the configuration information of the feedback information , Sending the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the time delay of the downlink channel to the network device. In this way, the network equipment can use the correlation or reciprocity between the uplink channel and the downlink channel, combined with the indication information of the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel to perform uplink channel estimation. On the one hand, under a given pilot density, the upper limit of channel estimation performance can be improved; on the other hand, under the condition of ensuring certain channel estimation performance, the pilot overhead can be reduced; in addition, it can match the dynamic channel well. Estimate demand. This solution can achieve both uplink channel estimation performance and uplink pilot overhead. In the case of smaller pilot overhead, the network equipment can obtain more accurate uplink CSI measurement information and improve the technical effect of data demodulation accuracy, so as to achieve The purpose of improving uplink coverage and uplink capacity.

The following describes the technical solutions in the embodiments of the present application clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. In order to make the embodiments of the present application clearer, part of the content and concepts related to the embodiments of the present application are introduced here in a unified manner.

1) A terminal device, also called a terminal, is an entity on the user side that is used to receive or transmit signals, and is used to send an uplink signal to a network device or receive a downlink signal from a network device. It includes devices that provide users with voice and/or data connectivity. For example, it may include a handheld device with a wireless connection function or a processing device connected to a wireless modem. The terminal device can communicate with the core network via a radio access network (RAN), and exchange voice and/or data with the RAN. The terminal equipment may include user equipment (UE), V2X terminal equipment, wireless terminal equipment, mobile terminal equipment, device-to-device communication (device-to-device, D2D) terminal equipment, machine-to-machine/machine-type communication ( machine-to-machine/machine-type communications, M2M/MTC) terminal equipment, Internet of things (IoT) terminal equipment, subscriber unit (subscriber unit), subscriber station (subscriber station), mobile station (mobile station) , Remote station (remote station), access point (access point, AP), remote terminal (remote terminal), access terminal (access terminal), user terminal (user terminal), user agent (user agent), or user equipment (user device) and so on. For example, it may include mobile phones (or "cellular" phones), computers with mobile terminal equipment, portable, pocket-sized, hand-held, mobile devices with built-in computers, and so on. For example, personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants, PDA), and other equipment. It also includes restricted devices, such as devices with low power consumption, or devices with limited storage capabilities, or devices with limited computing capabilities. Examples include barcodes, radio frequency identification (RFID), sensors, global positioning system (GPS), laser scanners and other information sensing equipment.

As an example and not a limitation, in the embodiment of the present application, the terminal device may also be a wearable device. Wearable devices can also be called wearable smart devices or smart wearable devices, etc. It is a general term for using wearable technology to intelligently design daily wear and develop wearable devices, such as glasses, gloves, watches, clothing and shoes Wait. A wearable device is a portable device that is directly worn on the body or integrated into the user's clothes or accessories. Wearable devices are not only a kind of hardware device, but also realize powerful functions through software support, data interaction, and cloud interaction. In a broad sense, wearable smart devices include full-featured, large-sized, complete or partial functions that can be achieved without relying on smart phones, such as smart watches or smart glasses, and only focus on a certain type of application function, and need to cooperate with other devices such as smart phones. Use, such as all kinds of smart bracelets, smart helmets, smart jewelry, etc. for physical sign monitoring.

The various terminal devices described above, if they are located on the vehicle (for example, placed in the vehicle or installed in the vehicle), can be regarded as vehicle-mounted terminal equipment, for example, the vehicle-mounted terminal equipment is also called on-board unit (OBU). ).

2) Network equipment is used to receive uplink signals from terminal equipment or send downlink signals to terminal equipment. For example, it includes access network (AN) equipment, radio access network (RAN) equipment, and access network equipment such as base stations (for example, access points). A device that communicates with wireless terminal devices in one or more cells. The base station can be used to convert received air frames and Internet Protocol (IP) packets into each other, and act as a router between the terminal device and the rest of the access network, where the rest of the access network may include an IP network. The network equipment can also coordinate the attribute management of the air interface. For example, the network equipment may include a long term evolution (LTE) system or an evolved base station (NodeB or eNB or e-NodeB, evolved NodeB) in a long term evolution-advanced (LTE-A) system, Or it may also include the next generation node B (gNB) or the next generation evolved base station (next generation node B, gNB) in the new radio (NR) system of the fifth generation mobile communication technology (the 5th generation, 5G) nodeB, ng-eNB), en-gNB (enhanced next generation node B, gNB): enhanced next-generation base stations; it may also include the centralized unit in the cloud radio access network (Cloud RAN) system unit, CU) and distributed unit (distributed unit, DU), or may also include a relay device, which is not limited in the embodiment of the present application.

In the embodiment of the present application, the network device may also include a core network device. The core network device includes, for example, a network device that processes and forwards user signaling and data. In a 4G system, a core network device is, for example, a mobility management entity (MME). The MME is a key control node of the access network of the LTE system defined by the 3rd generation partnership project (3GPP) protocol. It is responsible for the positioning and paging process of idle mode terminal devices, including relays. Simply put, MME is the core network equipment responsible for signaling processing. Or, in a 5G system, the core network equipment includes, for example, core network equipment such as an access management network element, a session management network element, or a user plane gateway. The user plane gateway can be a server with functions such as mobility management, routing, and forwarding of user plane data, and is generally located on the network side, such as a serving gateway (SGW) or a packet data network gateway (PGW) Or user plane function entity (UPF).

3) Doppler frequency deviation: The wavelength of electromagnetic wave radiation changes due to the relative movement of network equipment and terminal equipment, which results in the frequency deviation observed when the signal is received is different from the frequency of the actual signal emission. This phenomenon produces frequency deviation That is, Doppler shift.

4) Time delay: the time difference between the electromagnetic wave from the sending end to the receiving end.

5) Delay extension: A physical quantity describing the multipath effect in the time domain, defined as the difference between the maximum transmission delay and the minimum transmission delay.

6) Doppler extension: refers to the frequency range where the Doppler spectrum is not equal to zero. Assuming that the carrier frequency is fc and the maximum Doppler shift is fd, the frequency range referred to by Doppler expansion is fc-fd to fc+fd.

7) Angle of arrival: refers to the angle at which electromagnetic waves reach the antenna at the receiving end.

8). Departure angle: refers to the angle at which the electromagnetic wave leaves the transmitting end antenna.

9). The terms "system" and "network" in the embodiments of this application can be used interchangeably. The term "plurality" means two or more. The term "and/or" describes the association relationship of the associated objects, indicating that there can be three types of relationships, for example, A and/or B, which can mean: A alone exists, A and B exist at the same time, and B exists alone. In addition, the character "/", unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

Referring to FIG. 3, a flowchart of an information transmission method is provided in an embodiment of this application. In the following, the method is mainly applied to the wireless communication system shown in FIG. 1 as an example. The process of this method is introduced as follows.

S301. The network device sends configuration information of the feedback information to the terminal device, where the configuration information of the feedback information instructs the terminal device to feed back downlink channel information (or feedback information), where the downlink channel information includes the Doppler frequency offset and/or the downlink channel The delay of the downlink channel.

In some possible designs, the Doppler frequency offset of the downlink channel may include one or more of the following items: (1) Doppler frequency offset of each path of the downlink channel; (2) All of the downlink channel The largest Doppler frequency deviation among the Doppler frequency deviations of the paths; (3) The average Doppler frequency deviation of all paths of the downlink channel.

In some possible designs, the delay of the downlink channel may include one or more of the following items: (1) the delay of each path of the downlink channel; (2) the delay of all paths of the downlink channel Maximum delay; (3) The average delay of all paths of the downlink channel.

In some possible designs, the configuration information of the feedback information can instruct the terminal device to feed back the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel, and also instruct the terminal device to feed back other information related to the downlink channel, such as It can also instruct the terminal equipment to feed back the number of paths of the downlink channel, the delay spread of the downlink channel, the Doppler spread of the downlink channel, the angle of arrival and/or the departure angle of each path of the downlink channel, etc., help the network equipment to perform the uplink channel Estimated feedback information.

S302. The terminal device receives the configuration information of the feedback information sent by the network device, and feeds back downlink channel information to the network device, where the downlink channel information includes indication information of the Doppler frequency offset of the downlink channel and/or indication information of the time delay of the downlink channel .

It should be understood that the terminal device needs to obtain the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel before sending the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the downlink channel delay. . Therefore, before the terminal device feeds back the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the time delay of the downlink channel, the terminal device may also send a reference signal to the terminal device, so that the terminal device performs signal measurement based on the reference signal. In turn, the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel are obtained.

In some possible designs, the reference signal may include synchronization/broadcast channel resource block (SS/PBCH Block, SSB), channel state information reference signal (channel state information reference signal, CSI-RS), demodulation reference signal (demodulation reference signal) , DMRS), cell-specific reference signal (cell-specific reference signal, CRS), tracking reference signal (tracking reference signal, TRS), etc., which are not specifically limited in the embodiment of the present application.

In the embodiment of the present application, after receiving the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the time delay of the downlink channel, the network device may use the correlation or reciprocity between the uplink channel and the downlink channel. , The Doppler frequency offset of the downlink channel is estimated as the Doppler frequency offset of the uplink channel and/or the delay of the downlink channel is estimated as the delay of the uplink channel, and the uplink pilot frequency is combined with the uplink channel. Puller frequency offset and/or delay for uplink channel estimation can increase the upper limit of channel estimation performance under a given pilot density, or reduce pilot overhead while ensuring certain channel estimation performance, which can solve the problem. In some technologies, the uplink channel estimation performance is limited by the configured uplink pilot density and the pilot overhead is too large, so as to achieve the purpose of improving uplink coverage and capacity.

In some possible designs, the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel are used for uplink channel estimation.

In some possible designs, the downlink CSI configuration information can be used to configure the terminal equipment to feed back the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel. That is to say, the configuration information of the feedback information can be included in the downlink CSI configuration information. , And the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the time delay of the downlink channel are carried by the downlink CSI.

If the configuration information is downlink CSI configuration information, the configuration information of the feedback information is carried in radio resource control RRC signaling or media access control MAC signaling, that is, the downlink CSI configuration information is in RRC signaling or media access control (media access control). control, MAC) signaling.

In other possible designs, the configuration information of the feedback information may also be other information, or the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the time delay of the downlink channel may also be carried by other information. For example, it can also be carried by dedicated RRC signaling or MAC signaling (that is, the dedicated RRC signaling or MAC signaling only carries the Doppler frequency offset and/or the timing of the downlink channel for instructing the terminal equipment to feed back the downlink channel. Extension configuration information), the embodiment of the present application does not make specific restrictions here.

In some possible designs, the indication information of the feedback information fed back by the terminal device can be a direct value, that is, the value directly indicates the feedback information that needs to be fed back by the terminal device, and it can also be in the form of an index, which indirectly indicates that the terminal device needs The feedback information that is fed back is not specifically limited in the embodiment of the present application. For example, the downlink channel information may carry the value of the Doppler frequency offset of the downlink channel and/or the value of the delay of the downlink channel, or the downlink channel information may carry an index value, which corresponds to the Doppler frequency of the downlink channel The value of the bias and/or the value of the delay of the downlink channel. Of course, the above are just some examples. In specific implementation, the downlink channel information may also be other indication methods that carry the value of the Doppler frequency offset corresponding to the downlink channel and/or the value of the downlink channel delay.

Further, when the network device performs uplink channel estimation, in addition to considering the uplink pilot, it also combines downlink channel information (including Doppler frequency offset and/or downlink channel delay) fed back by the terminal device to perform uplink channel estimation. Therefore, before the network device performs uplink channel estimation, the network device needs to send the uplink pilot configuration to the terminal device, and after the terminal device receives the uplink pilot configuration, it sends the uplink pilot according to the configuration. After the network equipment receives the uplink pilot, it combines the received downlink channel information to perform uplink channel estimation.

A possible uplink channel estimation method is: the network equipment first performs channel estimation based on the pilot signal to generate the first channel estimation result. The specific method can refer to the existing LS method or MMSE method for estimation; then, the network equipment is based on the downlink Channel information (including Doppler frequency offset and/or time delay) corrects the first channel estimation result, obtains a second channel estimation result, and outputs the second channel estimation result as a final estimation result.

Another possible uplink channel estimation method is: the network device first estimates the autocorrelation matrix R _{HH of} the uplink channel H according to the downlink channel information (including Doppler frequency offset and/or time delay); then, the uplink channel H The autocorrelation matrix R _{HH is} brought into the MMSE estimator to derive and solve the uplink channel H to obtain the estimation result H _{mmse of the uplink channel H.} The specific implementation process of the above two methods will be described in detail in the following text.

Several specific embodiments are given below to describe in detail the specific implementation of the configuration information and the feedback information.

Example 1

(1) Configuration information of feedback information

In order for the terminal device to measure CSI, the network device can configure CSI-RS resource configuration information and CSI feedback information for CSI measurement through RRC. The involved RRC information elements (information elements, IE) include CSI measurement configuration information (CSI-MeasConfig), resource configuration of reference signals used for CSI measurement (CSI-ResourceConfig), CSI feedback configuration information (CSI-ReportConfig IE), etc. . Among them, the CSI-ReportConfig IE contains the CSI content that the terminal needs to feed back, such as CQI, PMI, RI, and so on. In this embodiment, the configuration of CSI-RS measurement may not be modified, but since new content needs to be fed back (delay of the downstream channel, Doppler frequency offset, etc.), it is possible to add instructions to the CSI-ReportConfig IE Indicates that new content needs to be fed back.

Exemplarily, configuration information of feedback information can be added in the CSI-ReportConfig IE, such as feedback channel delay enable configuration information (ReportChannelDelayEnable) and feedback Doppler frequency offset enable configuration information (ReportDopplerFreqOffsetEnable).

When the terminal needs to feed back channel delay information, configure the "ReportChannelDelayEnable" value to 1, such as "ReportChannelDelayEnable ENUMERATED{1}".

When the terminal needs to feed back the Doppler frequency shift, set the value of "ReportDopplerFreqOffsetEnable" to 1, such as "ReportDopplerFreqOffsetEnable ENUMERATED{1}".

If the values of "ReportChannelDelayEnable" and "ReportDopplerFreqOffsetEnable" are 0, or the "ReportChannelDelayEnable" and "ReportDopplerFreqOffsetEnable" are not configured, the terminal device does not feed back information such as channel delay information and Doppler frequency offset by default.

Optionally, the feedback cycle configuration can comply with the configuration in the existing "CSI-ReportConfig", for example, the cycle can be configured to 5ms, 10ms, 20ms, etc. In addition, a new field can also be added to the CSI-ReportConfig parameter to separately indicate the period of channel information feedback, for example, a new channel feedback period and offset (Channel-ReportPeriodicityAndOffset) field:

Wherein, for example, slots4 indicates that when the period is configured as 4 time slots (slots), the time slot offset value fed back may be 0, 1, 2, or 3 slots.

Of course, in addition to periodic feedback, it can also be configured as aperiodic feedback in CSI-ReportConfig.

In addition, the configuration information can also configure the quantization bit length of the channel delay and Doppler frequency offset.

One possible design is to additionally define a quantization bit length configuration information used to indicate channel delay and Doppler frequency offset in the CSI-ReportConfig IE. Another possible design is that the channel delay feedback configuration parameter "ReportChannelDelayConfig" and the Doppler frequency offset feedback configuration parameter "ReportDopplerFreqOffsetConfig" additionally indicate the value of the quantization bit length of the channel delay and Doppler frequency offset. The "ReportChannelDelayConfig" parameter includes the number of channels required "ChannelDelayPathNumber", the number of channel delay quantization bits "ChannelDelayQuantizationBitLength" and the channel delay differential quantization bit number "ChannelDelayDifferenceQuantizationBitLength", and the "ReportDopplerFreqOffsetConfig" parameter includes the Doppler offset The number of quantization bits in the positive part "IntegerPartQuantizationBitLength" and the number of quantization bits in the decimal part "IntegerPartQuantizationBitLength", for example:

It should be understood that the parameters related to the number of quantization bits are optional configurations, and default values can be used if they are not configured.

Among them, the meanings of parameters n1, K, K1, L1, and L2 refer to Table 2-1 and Table 2-2 below.

Optionally, if the quantization method of the feedback information is not configured, the terminal device may not feedback by default.

It should be noted that the reference signal for measuring channel information is not limited to CSI-RS, and SSB, DMRS, etc. can also be used. The content of the newly added feedback content is not limited to be indicated by CSI-ReportConfig IE, and can also be indicated by adding a new high-level signaling, but the completed function is similar. Regarding the configuration information of the feedback information, in addition to RRC signaling, MAC signaling can also be used to configure. In the following description, the description will not be repeated.

(2) The specific content of the feedback information (i.e., downlink channel information)

The specific content of the feedback information is shown in Table 2-. It is assumed that the multipath delays of the channels are all within the range of the cycle-prefix (CP). Assume that the time extension of CP is Tcp=Nc*Tc, where Tc is the time interval of sampling points in each orthogonal frequency division multiplexing (OFDM) symbol, and Nc represents the number of sampling points included in the CP . CP length and Tc, through configuration, network equipment and terminal equipment are known, and use the same value in the network equipment and terminal equipment. In the feedback, you can sort by time delay from small to large, that is, τ ₁ <τ ₂ <...<τ _n .

For example, when the CP length is 144 sampling points, K can take 8 bits, the indicated Nn is an integer between 0 and 255, and the number of paths n can take up to 6 or other larger values.

table 2-1

It should be noted that the time delay and Doppler frequency offset can be fed back separately, or only the time delay or Doppler frequency offset can be fed back. Which parameter is fed back depends on the specific content of the configuration information. In addition, the values of K and L can be configured through RRC signaling, and the default number of bits can also be used, which is not limited here.

In different implementation manners, a differential quantization method can also be used to reduce the number of feedback bits. When the multipath delays of the channels are not much different, the feedback overhead can be reduced. As shown in Table 2-2 below, the values of K, K1 and L can be configured through RRC signaling, or the default number of bits can be used.

Table 2-2

In practical applications, since the arrival angle and departure angle of each path of the downlink channel are different, the Doppler frequency offset may be different. When the Doppler frequency deviation of each path cannot be obtained, the average Doppler frequency deviation of each path can be used to approximate. In Table 2-1 and Table 2-2, only an example of feeding back the average Doppler frequency offset is given, which is a way of lower feedback overhead, but it does not exclude the Doppler frequency offset of each path being fed back. In addition, the feedback information can also be feedback delay extension, Doppler extension and other parameters.

The specific process for the terminal equipment to feed back downlink channel information to the network equipment is described above. The following describes the specific process for the network equipment to perform uplink estimation based on the above downlink channel information after receiving the downlink channel information fed back by the terminal equipment according to the above solution.

(3) Channel estimation algorithm implementation

Assume that the received signal model in the frequency domain is:

Y=HX+N (1)

Among them, X is the pilot signal vector, H is the fading channel matrix, N is the noise vector, and Y is the received signal vector. Among them, Y, X, and N are known, and H needs to be estimated.

Common pilot-based channel estimation algorithms include LS, MMSE, and maximum likelihood estimation algorithms. The following uses LS and MMSE as examples.

A. The LS estimation criterion needs to satisfy the following formula:

Where H _LS is the estimation of channel H. It can be obtained by mathematical derivation, H _LS =X ^-1 Y or H _LS =(X ^H X) ^-1 X ^H Y. The detailed derivation process will not be detailed here, and can refer to the existing technology.

B. The criteria for MMSE channel estimation are:

Among them, H _mmse is the estimation of channel H, which can be obtained by mathematical derivation:

H _mmse = R _HH (R _HH +(XX ^H ) ^-1 σ ² ) ^-1 H _LS (4)

Among them, R _HH =E(HH ^H ), is the autocorrelation matrix of the channel, and σ ² is the variance of the noise. The detailed derivation process will not be detailed here, and can refer to the existing technology.

The method for network equipment to perform uplink channel estimation in combination with downlink channel information is as follows:

Step 1: First use formula (2) to obtain the LS estimation of the channel matrix, namely H _LS .

Step 2: Through the Fourier transform, the channel H can be written as an expression in the time domain as:

Among them, f _DFT (□) is the Fourier transform function, α _n is the coefficient of the n-th path, τ _n is the time delay of the n-th path, and δ (□) is the impulse function.

Step 3: According to the time delay and Doppler frequency offset of the downlink channel fed back by the terminal equipment, combined with formula (5), the LS criterion is used to correct the channel estimation, and the actual channel H is calculated as follows:

Among them, N is the number of paths, and P is the total power of the multipath signal.

Of course, the MMSE criterion can also be used to obtain the MMSE estimation of the channel matrix in the above step 1. Correspondingly, the MMSE criterion can be used to modify the channel estimation in step 3, and the actual channel H can be obtained as follows:

Step 4: After obtaining the channel of the uplink pilot position according to step 3, the channel of the data position can be obtained by linear interpolation, Wiener filtering and other methods, and the existing algorithm can be used directly.

It should be understood that in the above formulas (6) and (7), the Doppler frequency offset for the downlink channel is optional. Because the Doppler frequency shift can be roughly estimated in the uplink when the terminal device is moving at low speed or not moving, and has little effect on the result, the terminal device does not need to feed back the Doppler frequency offset information. When the terminal equipment is moving at a high speed, because there are many downlink reference signals and periodic reference signals are sent, the Doppler frequency offset can be estimated more accurately. For example, the special time-frequency tracking reference signal (Tracking Reference Signal) can be used to accurately estimate the Doppler frequency offset. , TRS) to estimate.

In the uplink channel estimation, the Doppler frequency offset of the downlink feedback can be used directly, or it can be obtained by averaging or other filtering methods in combination with the uplink estimation result. Since the arrival angle and departure angle of each path are different, the Doppler frequency deviation may be different. When the Doppler frequency deviation of each path cannot be obtained, the average Doppler frequency deviation of each path can be used to approximate. In Table 2-1 and Table 2-2, only an example of feeding back the average Doppler frequency offset is given, which is a way of lower feedback overhead, but it does not exclude the Doppler frequency offset of each path being fed back.

When performing uplink channel estimation in this embodiment, the pilot signal is first used for channel estimation to generate the first channel estimation result, and then the first channel estimation result is calculated based on the downlink channel information (including Doppler frequency offset and/or time delay) Make corrections to obtain the final channel estimation result. Channel estimation can be performed at a given pilot frequency by combining the a priori information of the downlink channel fed back by the terminal equipment (the delay of the downlink channel and/or the Doppler frequency offset of the downlink channel) on the basis of the uplink pilot. To improve the upper limit of channel estimation performance, or reduce pilot overhead while ensuring certain channel estimation performance, the uplink channel estimation performance and uplink pilot overhead can be taken into account at the same time, so as to achieve the effect of improving uplink coverage and uplink capacity.

Example 2

In embodiment 1, the terminal equipment needs to feed back the delay information of each channel. Considering that the number of paths of the downlink channel is relatively large, the feedback overhead will be relatively large. In this embodiment 2, a downlink channel with low feedback overhead is given. Information feedback method.

(1) Channel information feedback configuration

The same as Embodiment 1, the configuration content of feedback information can be added in the CSI-ReportConfig IE, which is defined as feedback channel delay configuration information (ReportChannelDelayConfig) and feedback Doppler frequency offset configuration information (ReportDopplerFreqOffsetConfig). The ReportChannelDelayConfig parameter includes the maximum channel delay "MaxChannelDelay", the average delay "MeanDelay" and the number of delay quantization bits "DealyQuantizationBitLength". It should be understood that DealyQuantizationBitLength is an optional configuration location. If not configured, the default quantization length will be used.

Different from Embodiment 1, this embodiment considers the problem of feedback overhead, and can instruct the terminal device to only feed back the maximum delay in the multipath and the average delay of the multipath channel. The RRC layer configuration parameters can be as follows:

Among them, the meanings of K3, L1, and L2 are shown in Table 2-3 below.

(2) The specific content of the feedback information (ie, downlink channel information) is shown in Table 2-3:

Table 2-3

The calculation methods of multipath average delay mentioned in Table 2-3 include but are not limited to the following:

method one:

Method Two:

among them,

α _n is the fading coefficient of the n-th path of the channel.

Method three:

(3) Channel estimation algorithm implementation

In the first embodiment, the MMSE estimation algorithm is mentioned, and the estimated channel expression is:

H _mmse = R _HH (R _HH +(XX ^H ) ^-1 σ ² ) ^-1 H _LS (11)

Among them, R _HH =E(HH ^H ), is the autocorrelation matrix of the channel, and σ ² is the variance of the noise. Here, since H is unknown, it is not easy to obtain the autocorrelation matrix. In this embodiment, through an approximate method, it can be obtained:

Among them, L is the maximum time _extension of the multipath, τ mean is the average time delay of the multipath, and the number of rows and columns of _{R HH} _{are m, k, r m, and k} respectively for each element in the R _{HH matrix.}

According to formula (12), the time delay information fed back by the terminal equipment can be directly used to estimate R _HH .

In addition, the use of the Doppler frequency offset fed back by the terminal device in the second embodiment is the same as that in the first embodiment, and will not be repeated here.

In this embodiment, when performing uplink channel estimation, according to downlink channel information (including Doppler frequency offset and/or time delay), the autocorrelation matrix of the uplink channel is estimated, and then the autocorrelation matrix is directly imported into the MMSE algorithm. The uplink channel H is derived and solved, and the estimation result of the uplink channel is obtained. Channel estimation can be performed at a given pilot frequency by combining the a priori information of the downlink channel fed back by the terminal equipment (the delay of the downlink channel and/or the Doppler frequency offset of the downlink channel) on the basis of the uplink pilot. To improve the upper limit of channel estimation performance, or reduce pilot overhead while ensuring certain channel estimation performance, the uplink channel estimation performance and uplink pilot overhead can be taken into account at the same time, so as to achieve the effect of improving uplink coverage and uplink capacity.

The above two embodiments introduced a specific method for the terminal equipment to feed back downlink channel information (including the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel), as well as the specific method for uplink channel estimation in combination with uplink pilot and downlink channel information. The following describes the specific implementation process when the above-mentioned information transmission and channel estimation schemes in the embodiments of the present application are respectively applied to a PUSCH data demodulation scenario and a CSI measurement scenario.

Example 3

Referring to FIG. 4, an embodiment of the present application also provides a data demodulation method. The detailed steps of this method are as follows:

S401. The network device configures the time-frequency position of the uplink pilot in the DMRS through RRC signaling, and configures CSI-RS resource configuration information and CSI feedback information used for CSI measurement.

Wherein, the network device configures the time-frequency position of the uplink pilot in the DMRS, including the number of symbols, symbol position, and frequency domain density of the configured uplink pilot. For details, see the DMRS-UplinkConfig configuration information defined in the 3GPP TS 38.331 protocol.

Wherein, the CSI-RS resource configuration information configured by the network device for CSI measurement and the RRC information unit involved in the CSI feedback information may include CSI-MeasConfig, CSI-ResourceConfig, CSI-ReportConfig IE, etc. The CSI-ReportConfig IE contains the CSI content that the terminal device needs to feed back, such as CQI, PMI, RI, etc. In the application embodiment, the configuration of the CSI-RS measurement may not be modified, but a new indication is added in the CSI-ReportConfig IE, and the new indication is used to indicate that the terminal device needs to feed back new content (for example, the delay of the downlink channel, the Doppler Le frequency deviation, etc.). For the specific implementation method of this part of the content, please refer to the content of part (1) in the above-mentioned embodiment 1 or embodiment 2, which will not be repeated here.

S402: When the terminal device has data transmission, the network device sends scheduling information of PUSCH data to the terminal device to schedule uplink data.

Specifically, DCI can be used to instruct the terminal device to transmit information about PUSCH, including the time-frequency resource location of the scheduled PRB, modulation coding index (Modulation Coding Index, MCS), bandwidth indication, number of antenna ports, etc., for details, see 3GPP TS 38.212 DCI format 0_0 and DCI format 0-1 defined in the agreement.

S403. The network device sends a CSI-RS to the terminal device.

S404. The terminal device receives the CSI-RS sent by the network device, measures the downlink channel information according to the CSI-RS, including information such as the delay of the downlink channel and/or the Doppler frequency offset of the downlink channel, and then feeds back the measured downlink channel information To network equipment. For the content of the downlink channel information fed back by the terminal equipment, please refer to the content of the above-mentioned part (2) in the above-mentioned embodiment 1 or embodiment 2, which will not be repeated here.

S405. The terminal device sends the PUSCH data and the DMRS data according to the DMRS configuration information and the scheduling information of the PUSCH data.

S406. The network device receives the DMRS, PUSCH, and downlink channel information sent by the terminal device, and then performs uplink channel estimation according to the pilot in the DMRS and the downlink channel delay in the downlink channel information and/or the Doppler frequency offset of the downlink channel .

For the specific opposite party of the uplink channel estimation performed by the network equipment here, please refer to the content of part (3) in the above-mentioned embodiment 1 or embodiment 2, which will not be repeated here.

S407. The network device compensates the channel according to the channel at the estimated PUSCH data position, adopts an equalization algorithm such as LS or MMSE to obtain the equalized data, and then performs operations such as constellation decompression and decoding.

In this embodiment, when the network device performs PUSCH channel estimation, it also combines the prior information of the channel fed back by the terminal device (the delay of the downlink channel and/or the Doppler frequency offset of the downlink channel on the basis of the uplink pilot). ) Performing channel estimation can increase the upper limit of channel estimation performance under a given pilot density, or reduce pilot overhead while ensuring certain channel estimation performance, which can take into account both uplink channel estimation performance and uplink pilot overhead. In the case of small pilot overhead, the effect of improving the correct rate of data demodulation is realized, so as to achieve the purpose of improving uplink coverage and uplink capacity.

Example 4

Referring to FIG. 5, an embodiment of the present application also provides a signal measurement method. The detailed steps of this method are as follows:

S501. The network device configures the time-frequency position of the SRS through RRC signaling, CSI-RS resource configuration information used for CSI measurement, and CSI feedback information.

The network equipment configures the time-frequency position of the SRS, including configuring the number of symbols, symbol positions, and frequency domain positions of the SRS pilot. For details, refer to the SRS-Config information element defined in the 3GPP TS 38.331 protocol.

In order to measure CSI, RRC also needs to configure CSI-RS resource configuration information and CSI feedback information for CSI measurement. The involved RRC information elements may include CSI-MeasConfig, CSI-ResourceConfig, CSI-ReportConfig IE, etc. The CSI-ReportConfig IE contains the CSI content that the terminal device needs to feed back, such as CQI, PMI, RI, etc. In the implementation of this application, there is no need to modify the CSI-RS measurement configuration, that is, CSI-MeasConfig and CSI-ResourceConfig. However, since new content (ie, channel delay information, Doppler frequency offset, etc.) needs to be fed back, it is necessary to add an instruction to the CSI-ReportConfig IE. For the specific implementation method of this part of the content, please refer to the content of part (1) in the above-mentioned embodiment 1 or embodiment 2, which will not be repeated here.

S502: The network device sends a downlink reference signal used for downlink channel measurement, such as SSB, CSI-RS, etc.

S503: The terminal device performs downlink channel measurement according to the reference signal for channel measurement sent by the network device and feeds back the measured downlink CSI information. In the implementation of this application, in addition to feedback of CQI, PMI, and RI, information such as the delay of the downlink channel and the Doppler frequency offset of the downlink channel needs to be additionally fed back. The specific feedback information may be carried by a physical uplink control channel (PUCCH) or a PUSCH channel. For the specific feedback manner of the delay of the downlink channel and the Doppler frequency offset of the downlink channel, please refer to the content of the above-mentioned part (2) in the above-mentioned embodiment 1 or embodiment 2, which will not be repeated here.

S504: The terminal device sends an SRS signal to the network device.

S505: The network device receives the SRS pilot sent by the terminal device and the downlink channel information fed back by the terminal device, and performs channel estimation according to the SRS pilot and the downlink channel information, and estimates the channel position of the SRS.

S506: The network device performs uplink CSI measurement according to the SRS channel estimated in S505, including calculation of uplink CQI, PMI, RI, etc.

In this embodiment, when the network device performs SRS channel estimation, it also combines the prior information of the channel fed back by the terminal device (the time delay of the downlink channel and/or the Doppler frequency offset of the downlink channel on the basis of the uplink pilot). ) Channel estimation can increase the upper limit of channel estimation performance under a given pilot density, or reduce pilot overhead while guaranteeing a certain channel estimation performance. It can take into account both uplink channel estimation performance and uplink pilot overhead. Conducive to accurate measurement of uplink CSI.

It should be understood that the information transmission method and channel estimation method provided in the embodiments of the present application can be applied to other scenarios requiring uplink channel estimation in addition to PUSCH data demodulation scenarios and CSI measurement scenarios.

The foregoing embodiments in the embodiments of the present application can be combined with each other to achieve different technical effects.

The device used to implement the foregoing method in the embodiments of the present application will be described below in conjunction with the accompanying drawings. Therefore, all the above content can be used in the subsequent embodiments, and the repeated content will not be repeated.

Please refer to FIG. 6, which is a schematic structural diagram of an information receiving apparatus 600 provided by an embodiment of this application. The apparatus 600 may be the network equipment or the apparatus in the network equipment in the foregoing embodiment, and the apparatus 600 includes:

The sending unit 601 is configured to send configuration information of feedback information to a terminal device, where the configuration information of the feedback information indicates that the terminal device feeds back the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel;

The receiving unit 602 is configured to receive the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the time delay of the downlink channel from the terminal equipment.

In a possible design, the configuration information of the feedback information may also indicate the number of paths of the downlink channel fed back by the terminal device; the receiving unit 602 may also be configured to receive the number of paths of the downlink channel from the terminal device. Instructions.

In a possible design, the device may further include: a processing unit 603, configured to perform an uplink channel based on the pilot signal, the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel estimate.

In a possible design, the processing unit 603 is specifically configured to: perform channel estimation based on pilot signals to generate a first channel estimation result; and based on the Doppler frequency offset of the downlink channel and/or the downlink channel The time delay corrects the first channel estimation result, and obtains the second channel estimation result as the uplink channel estimation result.

_{In a possible design, the processing unit 603 is specifically configured to: estimate the autocorrelation matrix R HH of the} uplink channel H according to the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel; _{The autocorrelation matrix R HH of} the uplink channel H is brought into the minimum mean square error MMSE algorithm to derive and solve the uplink channel H, and the estimation result H _{mmse of} the uplink channel H is obtained.

Among them, all relevant content of the steps involved in the above method embodiments can be cited in the functional description of the corresponding functional module, which will not be repeated here.

Please refer to FIG. 7, which is a schematic structural diagram of an information sending apparatus 700 provided in an embodiment of this application. The apparatus 700 may be the terminal equipment in the above-mentioned embodiment or the apparatus in the terminal equipment, and the apparatus 700 includes:

The receiving unit 701 is configured to receive configuration information of feedback information from a network device, where the configuration information of the feedback information indicates that the terminal device feeds back the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel;

The sending unit 702 is configured to send indication information of the Doppler frequency offset of the downlink channel and/or indication information of the time delay of the downlink channel to the network device.

In a possible design, the configuration information of the feedback information may also indicate the number of paths of the downlink channel that the terminal device feeds back; the sending unit 702 may also be used to: send the number of paths of the downlink channel to the network device Instructions.

Please refer to FIG. 8, which is a schematic structural diagram of another information receiving apparatus 800 provided in an embodiment of this application. The apparatus 800 may be the network equipment or the apparatus in the network equipment in the foregoing embodiment, and the apparatus 800 includes:

The memory 801 is used to store computer programs;

The processor 802 is configured to execute the computer program stored in the memory 801, so that the apparatus executes the method executed by the network device in the foregoing method embodiment of the present application.

The processor involved in the embodiments of the present application can use field-programmable gate array (FPGA), application specific integrated circuit (ASIC), system on chip (SoC), and central Processor (central processor unit, CPU), network processor (NP), digital signal processing circuit (digital signal processor, DSP), microcontroller (microcontroller unit, MCU), or programmable controller (Programmable logic device, PLD) or other integrated chip implementation. In different implementation manners, the processor may include one or more processors, for example, include one or more central processing units (CPU), and the processors may be integrated in a chip, or may be the chip itself.

The memory involved in the embodiments of this application can be implemented through random access memory (RAM), read-only memory (Read-Only Memory, ROM), and Erasable Programmable Read-Only Memory. , EPROM), or portable read-only memory (Compact Disc Read-Only Memory, CD-ROM), etc.

In one possible manner, the processor and the memory may be connected to each other through a bus; the bus may be a peripheral component interconnection standard (PCI) bus or an extended industry standard architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, and so on. For ease of representation, only one thick line is used in FIG. 8, but it does not mean that there is only one bus or one type of bus.

Please refer to FIG. 9, which is a schematic structural diagram of another information sending apparatus 900 provided in an embodiment of this application. The apparatus 900 may be the terminal equipment or the apparatus in the terminal equipment in the foregoing embodiment, and the apparatus 900 includes:

The memory 901 is used to store computer programs;

The processor 902 is configured to execute the computer program stored in the memory 901, so that the apparatus executes the method executed by the terminal device in the foregoing method embodiment of the present application.

Refer to FIG. 10, which is a schematic structural diagram of another information receiving apparatus 1000 provided in an embodiment of this application. The apparatus 1000 may be the network equipment or the apparatus in the network equipment in the above embodiment. The apparatus 1000 includes a processor 1001 and a transceiver 1001.器1002.

Wherein, the processor 1001 is configured to support the apparatus to perform corresponding functions of the network device in the foregoing method embodiment of the present application. The transceiver 1002 is used to support communication between the network device and other devices (such as terminal devices). The transceiver 1002 may be an independent receiver, an independent transmitter, a transceiver with integrated transceiver functions, or an interface circuit.

Refer to FIG. 11, which is a schematic structural diagram of another information sending apparatus 1100 provided in an embodiment of this application. The apparatus 1100 may be the terminal equipment or the apparatus in the terminal equipment in the foregoing embodiment. The apparatus 1100 includes a processor 1101 and a transceiver 1101.器1102.

Wherein, the processor 1101 is configured to support the apparatus to perform corresponding functions of the terminal device in the foregoing method embodiments of the present application. The transceiver 1102 is used to support communication between the terminal device and other devices (such as network devices). The transceiver 1102 may be an independent receiver, an independent transmitter, a transceiver with integrated transceiver functions, or an interface circuit.

Based on the same technical concept, an embodiment of the present application further provides a computer-readable storage medium, including a program or instruction, and when the program or instruction runs on a computer, the method in the embodiment of the present application is executed.

Based on the same technical concept, an embodiment of the present application further provides a chip, which is coupled with a memory, and is configured to read and execute program instructions stored in the memory to implement the method in the embodiment of the present application.

Based on the same technical concept, an embodiment of the present application further provides a wireless communication system, and the wireless communication system includes the network equipment and terminal equipment involved in the embodiments of the present application.

Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, this application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

This application is described with reference to flowcharts and/or block diagrams of methods, equipment (systems), and computer program products according to this application. It should be understood that each process and/or block in the flowchart and/or block diagram, and the combination of processes and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing equipment to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing equipment are used to generate It is a device that realizes the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing equipment to work in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction device. The device implements the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operation steps are executed on the computer or other programmable equipment to produce computer-implemented processing, so as to execute on the computer or other programmable equipment. The instructions provide steps for implementing the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

Obviously, those skilled in the art can make various changes and modifications to this application without departing from the protection scope of this application. In this way, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, then this application is also intended to include these modifications and variations.

Claims

An information receiving method, characterized in that it comprises:

Sending configuration information of feedback information to a terminal device, where the configuration information of the feedback information indicates that the terminal device feeds back the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel;

Receiving the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the time delay of the downlink channel from the terminal device.
The method according to claim 1, wherein the configuration information of the feedback information is downlink CSI configuration information, indication information of the Doppler frequency offset of the downlink channel and/or indication information of the time delay of the downlink channel Carried by downlink CSI.
The method according to claim 2, wherein the configuration information of the feedback information is carried in radio resource control RRC signaling or medium access control MAC signaling.
The method according to claim 1, wherein the Doppler frequency offset of the downlink channel comprises:

The Doppler frequency offset of each path of the downlink channel; or

The largest Doppler frequency deviation among the Doppler frequency deviations of all paths of the downlink channel; or

The average Doppler frequency deviation of all paths of the downlink channel.
The method according to claim 1, wherein the time delay of the downlink channel comprises:

The time delay of each path of the downlink channel; or

The maximum time delay among the time delays of all paths of the downlink channel; or

The average delay of all paths of the downlink channel.
The method according to claim 1, wherein the configuration information of the feedback information also indicates the number of paths for the terminal device to feed back the downlink channel;

After sending the configuration information of the feedback information to the terminal device, it also includes:

Receiving the indication information of the path number of the downlink channel from the terminal device.
The method according to any one of claims 1-6, further comprising:

Perform uplink channel estimation based on the pilot signal, the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel.
The method according to claim 7, wherein the uplink channel estimation is performed based on the pilot signal, the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel, comprising:

Perform channel estimation based on the pilot signal, and generate a first channel estimation result;

Correcting the first channel estimation result based on the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel, and obtaining a second channel estimation result as the result of the uplink channel estimation.
The method according to claim 7, wherein the uplink channel estimation is performed based on the pilot signal, the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel, comprising:

Estimating the autocorrelation matrix R HH of the uplink channel H according to the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel;

The autocorrelation matrix R HH of the uplink channel H is brought into the minimum mean square error MMSE algorithm to derive and solve the uplink channel H, and the estimation result H mmse of the uplink channel H is obtained.
An information sending method, characterized in that it comprises:

Receiving configuration information of feedback information from a network device, where the configuration information of the feedback information indicates that the terminal device feeds back the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel;

Send the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the time delay of the downlink channel to the network device.
The method according to claim 10, wherein the configuration information of the feedback information is downlink CSI configuration information, indication information of the Doppler frequency offset of the downlink channel and/or indication information of the downlink channel delay Carried by downlink CSI.
The method according to claim 11, wherein the configuration information of the feedback information is carried in radio resource control RRC signaling or medium access control MAC signaling.
The method according to claim 10, wherein the Doppler frequency offset of the downlink channel comprises:

The Doppler frequency offset of each path of the downlink channel; or

The largest Doppler frequency deviation among the Doppler frequency deviations of all paths of the downlink channel; or

The average Doppler frequency deviation of all paths of the downlink channel.
The method according to claim 10, wherein the time delay of the downlink channel comprises:

The time delay of each path of the downlink channel; or

The maximum time delay among the time delays of all paths of the downlink channel; or

The average delay of all paths of the downlink channel.
The method according to claim 10, wherein the configuration information of the feedback information also indicates the number of paths for the terminal device to feed back the downlink channel;

After receiving the configuration information of the feedback information from the network device, it also includes:

Sending the indication information of the number of paths of the downlink channel to the network device.
An information receiving device, characterized in that it comprises:

A sending unit, configured to send configuration information of feedback information to a terminal device, where the configuration information of the feedback information indicates that the terminal device feeds back the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel;

The receiving unit is configured to receive the indication information of the Doppler frequency offset of the downlink channel and/or the indication information of the time delay of the downlink channel from the terminal equipment.
The apparatus according to claim 16, wherein the configuration information of the feedback information is downlink CSI configuration information, indication information of the Doppler frequency offset of the downlink channel and/or indication information of the time delay of the downlink channel Carried by downlink CSI.
The apparatus according to claim 17, wherein the configuration information of the feedback information is carried in radio resource control RRC signaling or medium access control MAC signaling.
The apparatus according to claim 16, wherein the Doppler frequency offset of the downlink channel comprises:

The Doppler frequency offset of each path of the downlink channel; or

The largest Doppler frequency deviation among the Doppler frequency deviations of all paths of the downlink channel; or

The average Doppler frequency deviation of all paths of the downlink channel.
The apparatus according to claim 16, wherein the time delay of the downlink channel comprises:

The time delay of each path of the downlink channel; or

The maximum time delay among the time delays of all paths of the downlink channel; or

The average delay of all paths of the downlink channel.
The apparatus according to claim 16, wherein the configuration information of the feedback information further indicates the number of paths of the downlink channel that the terminal device feeds back;

The receiving unit is further configured to receive indication information of the number of paths of the downlink channel from the terminal equipment.
The device according to any one of claims 16-21, wherein the device further comprises:

The processing unit is configured to perform uplink channel estimation based on the pilot signal, the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel.
The device according to claim 22, wherein the processing unit is specifically configured to:

Perform channel estimation based on the pilot signal, and generate a first channel estimation result;

Correcting the first channel estimation result based on the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel, and obtaining a second channel estimation result as the result of the uplink channel estimation.
The device according to claim 22, wherein the processing unit is specifically configured to:

Estimating the autocorrelation matrix R HH of the uplink channel H according to the Doppler frequency offset of the downlink channel and/or the time delay of the downlink channel;

The autocorrelation matrix R HH of the uplink channel H is brought into the minimum mean square error MMSE algorithm to derive and solve the uplink channel H, and the estimation result H mmse of the uplink channel H is obtained.
An information sending device, characterized in that it comprises:

A receiving unit, configured to receive configuration information of feedback information from a network device, where the configuration information of the feedback information indicates that the terminal device feeds back the Doppler frequency offset of the downlink channel and/or the delay of the downlink channel;

The sending unit is configured to send indication information of the Doppler frequency offset of the downlink channel and/or indication information of the time delay of the downlink channel to the network device.
The apparatus according to claim 25, wherein the configuration information of the feedback information is downlink CSI configuration information, indication information of the Doppler frequency offset of the downlink channel and/or indication information of the downlink channel delay Carried by downlink CSI.
The apparatus according to claim 26, wherein the configuration information of the feedback information is carried in radio resource control RRC signaling or medium access control MAC signaling.
The apparatus according to claim 25, wherein the Doppler frequency offset of the downlink channel comprises:

The Doppler frequency offset of each path of the downlink channel; or

The largest Doppler frequency deviation among the Doppler frequency deviations of all paths of the downlink channel; or

The average Doppler frequency deviation of all paths of the downlink channel.
The apparatus according to claim 25, wherein the time delay of the downlink channel comprises:

The time delay of each path of the downlink channel; or

The maximum time delay among the time delays of all paths of the downlink channel; or

The average delay of all paths of the downlink channel.
The apparatus according to claim 25, wherein the configuration information of the feedback information further indicates the number of paths of the downlink channel that the terminal device feeds back;

The sending unit is further configured to send indication information of the path number of the downlink channel to the network device.
An information receiving device, characterized in that it comprises:

Memory, used to store computer programs;

The processor is configured to execute the computer program stored in the memory, so that the device executes the method according to any one of claims 1-9.
An information receiving device, characterized in that it comprises:

Memory, used to store computer programs;

The processor is configured to execute the computer program stored in the memory, so that the device executes the method according to any one of claims 10-15.
A computer-readable storage medium, characterized by comprising a program or instruction, when the program or instruction runs on a computer, the method according to any one of claims 1-9 is executed.
A computer-readable storage medium, characterized by comprising a program or instruction, when the program or instruction runs on a computer, the method according to any one of claims 10-15 is executed.
A chip, characterized in that the chip is coupled with a memory, and is used to read and execute program instructions stored in the memory to implement the method according to any one of claims 1-9.
A chip, characterized in that the chip is coupled with a memory, and is used to read and execute program instructions stored in the memory to implement the method according to any one of claims 10-15.