Transmission method and apparatus for reference signals

Abstract

The application provides a transmission method and device of a reference signal, which can realize full-channel CSI measurement under a hybrid beamforming architecture. The method comprises the following steps: a network device outputs NXM reference signals by using NXM antenna ports on NXM resource elements (REs), the NXM reference signals correspond to the NXM REs one by one, each antenna port in the NXM antenna ports is connected with each radio frequency link in N radio frequency links, and the NXM reference signals are used to measure downlink channel information of the NXM antenna ports, wherein N and M are positive integers; a terminal device receives the NXM reference signals output by the NXM antenna ports of the network device on the NXM REs, and determines the downlink channel information of the NXM antenna ports according to the received NXM reference signals; the terminal device feeds back the downlink channel information of the NXM antenna ports to the network device; and the network device receives the downlink channel information of the NXM antenna ports fed back by the terminal device.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of communication, and more particularly, to a transmission method and apparatus of a reference signal. BACKGROUND

[0002] A large amount of idle bandwidth in a millimeter wave (mmWave) frequency band can be utilized, thereby greatly improving the transmission capacity of a communication system. Due to the small wavelength of the millimeter wave, a device can be equipped with more (for example, hundreds of) antenna units to form a massive multiple-input multiple-output (massive MIMO) antenna array, thereby greatly improving the spectral efficiency.

[0003] In a conventional MIMO system, a full-digital beamforming technology is adopted, and each antenna needs a dedicated radio frequency link (including a mixer, a digital-to-analog converter, and / or the like) to support, and the number of radio frequency links is equal to the number of antennas. At this time, the link overhead is large, and the cost is expensive. For this reason, a hybrid beam-forming (HBF) technology is proposed. The HBF technology can effectively reduce the overhead of the radio frequency link and the system complexity when applied to a millimeter wave massive antenna system. Therefore, the hybrid beam-forming is gradually replacing the full-digital beam-forming. However, due to the fact that the discussion on the hybrid beam-forming is still very limited, how to perform channel measurement under the hybrid beam-forming architecture becomes a problem to be solved urgently. SUMMARY

[0004] The present application provides a transmission method and apparatus of a reference signal, which can realize full-channel channel state information (CSI) measurement under a hybrid beam-forming architecture.

[0005] In a first aspect, a method for transmitting a reference signal is provided. The method can be performed by a network device, a component (e.g., a processor, a chip, or a chip system) of the network device, or a logic module or software that can implement all or part of the function of the network device. The method includes: outputting N×M reference signals using N×M antenna ports on N×M resource elements (REs), the N×M reference signals correspond to the N×M REs one-to-one, each of the N×M antenna ports is connected to each of N radio frequency (RF) chains, and the N×M reference signals are used to measure downlink channel information of the N×M antenna ports, where N and M are positive integers; the N×M REs include M groups of REs, each group of REs includes N REs, and each group of REs occupies N subcarriers and one symbol; and a weight w m×N+n of the reference signal output on the nth RE of the mth group is

[0006]

[0007] where w m×N+n is an N×M vector, is an N×M vector, a m,n,i in the vector m,n,i is equal to 1, and the remaining a m,n,i are equal to 0, 0≤m≤M-1, 0≤n≤N-1, and 0≤i≤N-1; and the downlink channel information of the N×M antenna ports is received.

[0008] Exemplarily, the reference signal can be a channel state information reference signal (RS), that is, a CSI-RS.

[0009] Based on the above technical solution, under the HBF architecture (the number of RF chains is much smaller than the number of antenna ports), the network device (base station) can transmit N×M reference signals to the terminal device through N×M antenna ports, and can measure the downlink channel corresponding to the N×M antenna ports, so as to obtain the CSI information of the full channel.

[0010] In combination with the first aspect, in some implementations of the first aspect, when m takes a certain value, the vectors [a m,n,0 ,…,a m,n,i ,…,a m,n,N-1 corresponding to different values of n are orthogonal; or, when n takes a certain value, the vectors [a corresponding to different values of m are orthogonal. Through the method, the weights w m×N+n of the reference signals corresponding to different REs are orthogonal, which can better distinguish the reference signals on different REs, and thus can improve the reception performance of the receiving end / terminal device.

[0011] With reference to the first aspect, in some implementations of the first aspect, the N*M REs occupy N subcarriers and M symbols. Different reference signals are transmitted at different REs, which can enable the terminal device to distinguish between different reference signals.

[0012] With reference to the first aspect, in some implementations of the first aspect, N=2, M=4, 0≤n≤1, 0≤m≤3; when m=0, n=0, when m=0, n=1, when m=1, n=0, when m=1, n=1, when m=2, n=0, when m=2, n=1, when m=3, n=0, when m=3, n=1, where w0, w1, w2, w3, w4, w5, w6 and w7 are weights corresponding to the 8 reference signals output by the 8 antenna ports, respectively. The weights of the 8 reference signals output by the 8 antenna ports are orthogonal, which can improve the reception performance of the terminal device, thereby enabling full-channel CSI measurement.

[0013] With reference to the first aspect, in some implementations of the first aspect, when N=2, M=2, 0≤n≤1, 0≤m≤1; when m=0, n=0, when m=0, n=1, when m=1, n=0, when m=1, n=1, where w0, w1, w2 and w3 are weights corresponding to the 4 reference signals output by the 4 antenna ports, respectively. The weights of the 4 reference signals output by the 4 antenna ports are orthogonal, which can improve the reception performance of the terminal device, thereby enabling full-channel CSI measurement.

[0014] It should be noted that the weights used by the network device when performing amplitude and phase weighting on the reference signals can be agreed by the network device and the terminal device in advance, or specified in the wireless communication protocol, or determined by the network device itself and notified to the terminal device.

[0015] With reference to the first aspect, in some implementations of the first aspect, the method further comprises: correcting the downlink channel information. Since the analog part is implemented using a phase shifter under the HBF architecture, the phase shifter will have non-ideal factors, causing the phase shifter to deviate. Non-ideal correction is performed on the channel information fed back by the terminal device, which can improve the accuracy of channel measurement.

[0016] In a second aspect, a communication apparatus is provided. The apparatus can be a network device, a component or a module of a network device, or a logical module capable of implementing all or part of the network device functions. The apparatus includes a sending module configured to output N×M reference signals using N×M resource elements (REs) and N×M antenna ports, the N×M reference signals correspond to the N×M REs one-to-one, each of the N×M antenna ports is connected to each of N radio frequency (RF) chains, and the N×M reference signals are used to measure downlink channel information of the N×M antenna ports, where N and M are positive integers; the N×M REs include M groups of REs, each group of REs includes N REs, and each group of REs occupies N subcarriers and one symbol; and a weight w m×N+n is output on an nth RE of an mth group of REs.

[0017]

[0018] where w m×N+n is an N×M vector, is an N×M vector, a m,n,i in the vector [a m,n,i is equal to 1 and the other a m,n,i is equal to 0, 0≤m≤M-1, 0≤n≤N-1, and 0≤i≤N-1; and a receiving module configured to receive the downlink channel information of the N×M antenna ports.

[0019] In some implementations of the second aspect, when m is constant, vectors [a m,n,0 ,…,a m,n,i ,…,a m,n,N-1 ] corresponding to different values of n are orthogonal; or when n is constant, vectors [a ] corresponding to different values of m are orthogonal.

[0020] In some implementations of the second aspect, the N×M REs occupy N subcarriers and M symbols.

[0021] In some implementations of the second aspect, N is equal to 2 and M is equal to 4, 0≤n≤1, and 0≤m≤3; when m=0 and n=0, when m=0 and n=1, when m=1 and n=0, when m=1 and n=1, when m=2 and n=0, when m=2 and n=1, when m=3 and n=0, when m=3 and n=1, Wherein, w0, w1, w2, w3, w4, w5, w6 and w7 are weight values corresponding to 8 reference signals output by 8 antenna ports respectively.

[0022] With reference to the second aspect, in some implementations of the second aspect, N is equal to 2, M is equal to 2, 0≤n≤1, 0≤m≤1; when m=0, n=0, when m=0, n=1, when m=1, n=0, when m=1, n=1, Wherein, w0, w1, w2 and w3 are weight values corresponding to 4 reference signals output by 4 antenna ports respectively.

[0023] With reference to the second aspect, in some implementations of the second aspect, the apparatus further comprises a processing module configured to modify the downlink channel information.

[0024] The third aspect provides a communication device, comprising a processor and a transceiver, wherein the transceiver is configured to receive computer codes or instructions and transmit the computer codes or instructions to the processor, and the processor is configured to execute the computer codes or instructions to implement the transmission method of the reference signal in the first aspect or any possible implementation manner of the first aspect.

[0025] The fourth aspect provides a communication apparatus, comprising: an input / output interface configured to obtain input information and / or output information; and a logic circuit configured to execute the method in the first aspect or any possible implementation manner of the first aspect, and process the input information and / or generate the output information.

[0026] The fifth aspect provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a communication device to make the communication device implement the transmission method of the reference signal in the first aspect or any possible implementation manner of the first aspect.

[0027] The sixth aspect provides a computer program product comprising instructions, which are executed by a computer to make a communication device implement the transmission method of the reference signal in the first aspect or any possible implementation manner of the first aspect.

[0028] It should be understood that the second aspect to the sixth aspect of the present application are consistent with the technical solution of the first aspect of the present application, and the beneficial effects obtained by each aspect and the corresponding possible implementation manner are similar, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a system architecture schematic diagram to which the embodiments of the present application are applicable.

[0030] Figure 2 is an architecture example diagram of digital beamforming technology.

[0031] Figure 3 is an architecture example diagram of hybrid beamforming technology.

[0032] Figure 4 is a schematic diagram of downlink full channel CSI measurement.

[0033] Figure 5 is a schematic diagram of beam domain CSI measurement based on HBF system.

[0034] Figure 6 is an architecture example diagram of a hybrid beamforming technology to which embodiments of the present application are applicable.

[0035] Figure 7 is a schematic interaction flow diagram of a transmission method of a reference signal according to an embodiment of the present application.

[0036] Figure 8 is a frequency domain and time domain schematic diagram of 8 RE occupation according to an embodiment of the present application.

[0037] Figure 9 is a frequency domain and time domain schematic diagram of 4 RE occupation according to an embodiment of the present application.

[0038] Figure 10 is a schematic block diagram of a communication device according to an embodiment of the present application.

[0039] Figure 11 is a schematic block diagram of a communication device according to an embodiment of the present application. DETAILED DESCRIPTION

[0040] The technical solutions in the present application will be described below with reference to the drawings.

[0041] The embodiments of the present application can be applied to various communication systems, such as a wireless local area network (WLAN), a narrow band-internet of things (NB-IoT), a global system for mobile communications (GSM), an enhanced data rate for gsm evolution (EDGE), a wideband code division multiple access (WCDMA), a code division multiple access 2000 (CDMA2000), a time division-synchronization code division multiple access (TD-SCDMA), a long term evolution (LTE), satellite communication, a 5th generation (5G) system, and three big application scenarios of the 5G communication system: enhanced mobile broadband (eMBB), ultra reliable and low latency communications (URLLC), and massive machine type communications (mMTC).

[0042] The communication system suitable for the present application includes one or more transmitting ends and one or more receiving ends. Among them, the signal transmission between the transmitting end and the receiving end can be transmitted through radio waves, or can be transmitted through visible light, laser, infrared, optical fiber and other transmission media. Exemplarily, one of the transmitting end and the receiving end can be a terminal device, and the other can be a network device.

[0043] The terminal device involved in the embodiments of the present application can include various handheld devices, vehicle-mounted devices, wearable devices, computing devices or other processing devices connected to a wireless modem with wireless communication function. The terminal can be a mobile station (MS), a subscriber unit, a user equipment (UE), a cellular phone, a smart phone, a wireless data card, a personal digital assistant (PDA) computer, a tablet computer, a wireless modem, a handset, a laptop computer, a machine type communication (MTC) terminal, etc. Among them, the user equipment includes a vehicle user equipment.

[0044] Exemplarily, the network device can be an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home evolved Node B (or home Node B, HNB), a baseband unit (BBU), an access point (AP) in a wireless fidelity (WiFi) system, a wireless relay node, a wireless backhaul node, a transmission point (TP), or a transmission and reception point (TRP), and the like, and can also be a gNB or a transmission point (such as a TRP or a TP) in new radio (NR), one or a group (including multiple) antenna panels of a base station in NR, or a network node constituting a gNB or a transmission point, such as a building baseband unit (BBU) or a distributed unit (DU), or the like, or a network device in a 5G network or a future evolved PLMN network, and the like. It can be understood that all or part of the functions of the network device in the present application can also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform (such as a cloud platform).

[0045] The product form of the network device is very rich. For example, in the product implementation process, the BBU can be integrated with the radio frequency unit (RFU) in the same device, and the device is connected to the antenna array through a cable (such as but not limited to a feeder). The BBU can also be separated from the RFU and arranged between them through an optical fiber, and communicate through, for example, but not limited to, a common public radio interface (CPRI) protocol. In this case, the RFU is usually referred to as a remote radio unit (RRU), which is connected to the antenna array through a cable. In addition, the RRU can also be integrated with the antenna array, for example, the active antenna unit (AAU) product on the market currently adopts this structure.

[0046] In addition, the BBU can be further decomposed into multiple parts. For example, the BBU can be further subdivided into a centralized unit (CU) and a distribute unit (DU) according to the real-time nature of the processed services. The CU is responsible for processing non-real-time protocols and services, and the DU is responsible for processing physical layer protocols and real-time services. Further, part of the physical layer functions can also be separated from the BBU or the DU and integrated in the AAU.

[0047] As shown in FIG. 1, a system architecture diagram to which embodiments of the present application are applicable is shown. The system includes network devices and terminal devices. The network device in the embodiments of the present application can be a base station. Figure 1

[0048] To facilitate understanding of the embodiments of the present application, the concepts involved in the embodiments of the present application are first explained:

[0049] Beamforming technology: also called beamforming, spatial filtering, is a signal processing technology for directional transmission and / or reception of array signals. It can be applied to the signal transmitting end and the signal receiving end. Beamforming technology adjusts the parameters of the basic units of the phase array, so that the signals of certain angles obtain constructive interference, and the signals of other angles obtain destructive interference, thereby generating a beam. In a multiple-input multiple-output (MIMO) system, beamforming can comprehensively improve the quality of received signals and improve the throughput of the system. According to the location of beamforming in the signal path, beamforming technology can be divided into digital beamforming technology and analog beamforming technology.

[0050] Digital beamforming (DBF) technology: also known as full-digital beamforming. This technology refers to the arbitrary control of antenna amplitude and phase (i.e., amplitude and / or phase) weighting before the digital baseband (i.e., in the time domain or digital domain), thereby generating a beam. In digital beamforming technology, each antenna (which can also be understood as an antenna port, an antenna unit, an antenna subarray, etc.) corresponds to an RF link or RF transmission channel or data channel, and multiple RF links participate in generating a beam, so multiple data streams can be transmitted together. Digital beamforming uses a complex hardware structure, which can flexibly adjust the phase and amplitude to produce a more accurate beam. However, when DBF technology is used in a MIMO system with a large number of antennas, the hardware implementation of the entire system can be very complex and costly.

[0051] ​Analog beamforming (ABF) technology: refers to applying amplitude and phase weights to analog signals before analog baseband (i.e. in the frequency domain range or analog domain), thereby generating a beam. In the analog beamforming technology, a low-cost analog phase shifter is used, which can only adjust the phase and is difficult or even impossible to adjust the amplitude, and the generated beam is not necessarily accurate. The analog beamforming technology has a simple hardware structure, low implementation cost, no multiple RF links, and can only transmit a single data stream.

[0052] Hybrid beamforming technology: a technology that divides beamforming between the digital domain and the analog domain to reduce the cost related to the number of RF links. Hybrid beamforming technology includes two parts: one part is implemented by low-dimensional digital beamforming (i.e. digital part), and the other part is implemented by high-dimensional analog beamforming (i.e. analog part). For large-scale MIMO systems, combining the advantages of the above-mentioned digital beamforming and analog beamforming, hybrid beamforming technology is proposed, so that under the condition of meeting the hardware conditions, its gain can reach the effect of full-digital beamforming as much as possible.

[0053] In a specific implementation, the HBF technology can be implemented by using a hybrid precoder. The hybrid precoder can include an analog precoder (for implementing the above-mentioned analog part) and a digital precoder (for implementing the above-mentioned digital part). Among them, the analog precoder can be implemented by a phase shifter, and the digital precoder can be implemented by a radio frequency link.

[0054] Beam domain channel state information measurement: a MIMO system, the base station side configures n antennas, and sends m port CSI-RS through beamforming, where m < n, and the UE measures the CSI according to the m port CSI-RS and feeds back the related information to the base station. The UE can only observe the channel information of the m port weighted by the beam, so it is a partial CSI measurement.

[0055] Full channel CSI measurement: a MIMO system, the base station configures n antennas, and each antenna maps a port of CSI-RS respectively, and sends n port CSI-RS, and the UE measures the CSI according to the n port CSI-RS and feeds back the related information to the base station. The UE side observes the channel information of n ports, so it is a full channel CSI measurement.

[0056] With the development of wireless communication technology, large-scale MIMO technology has been paid more and more attention, which can greatly improve the transmission rate and spectrum efficiency of wireless communication system. In order to fully utilize the large-scale antenna array, full-digital precoding technology / digital beamforming technology is often used, which requires each antenna to be connected with a data channel / radio frequency link. For example, Figure 2As shown in (a), an example diagram of the architecture of digital beamforming technology is shown. Each antenna corresponds to one RF link. For each RF link, when the signal is transmitted, the digital signal is first digitally beamformed at the baseband 21, and then converted into an analog signal via a digital-to-analog converter (DAC) 22. The analog signal corresponding to one RF link 23 is mapped to one antenna port 24 and transmitted by the antenna port 24. It can be seen that since digital beamforming is performed before the DAC, one DAC needs to be set for each RF link. For a MIMO system with a large number of antennas, this may lead to very complex hardware implementation of the entire system, high cost, and greatly increased power consumption. In addition, in a large-scale MIMO system, the number of antennas is often large. If a full-digital MIMO system is used, the number of RF links is equal to the number of antennas, and the cost and power consumption are unbearable.

[0057] In order to reduce the required RF links and at the same time obtain greater overall gain, a compromise solution, i.e., hybrid beamforming technology, can be used. As shown in (a), an example diagram of the architecture of hybrid beamforming technology is shown. Figure 3 Figure 3 It includes Figure 3 (a) a fully-connected structure as shown in (a) and Figure 3 (b) a partially-connected structure as shown in (b). In Figure 3 (a), N RF links 31a are connected to M antennas 33a through N x M phase shifters 32a. Each RF link 31a is connected to each antenna 33a through one phase shifter 32a, and each antenna 33a is connected to multiple phase shifters 32a. In Figure 3 (b), N RF links 31b are connected to N x M antennas 33b through N x M phase shifters 32b. One RF link 31b is connected to multiple antennas 33b, and each antenna 33b is connected to only one phase shifter 32b. It can be seen that in actual applications, the partially-connected structure is more cost-effective and easier to implement in engineering. In the HBF system, one RF link is often connected to multiple antennas, and a time-division adjustable analog phase shifter is generally configured between the RF output port and each antenna. In this way, baseband digital precoding combined with analog precoding configured by the phase shifter completes hybrid beamforming precoding.

[0058] ​A base station can accurately transmit signals to a target user through multi-antenna beamforming technology, provided that the base station obtains the downlink full channel state information of the user, that is, a corresponding CSI measurement scheme is required. In the above wireless communication system, in order to improve the quality of the received signal and improve the throughput of the system, the beamforming technology can be applied to the base station. The base station and the UE can communicate downlink. Further, in order to effectively reduce the overhead of the radio frequency link and the complexity of the system, the HBF technology is applied to the base station and the communication between the base station and the UE. However, when performing channel measurement, since the number of RF links under the HBF architecture is much smaller than the number of antenna ports, and the number of RF links under the DBF architecture is almost the same as the number of antenna ports, it can be seen that the downlink channel measurement method of the DBF architecture cannot be reused under the HBF architecture. Even if it is reused, the channel information corresponding to all antenna ports cannot be obtained.

[0059] In order to facilitate the understanding of the embodiments of the present application, the existing CSI measurement technology is briefly introduced.

[0060] As shown in Figure 4 , a schematic diagram of downlink full channel CSI measurement is shown. The base station generates CSI-RS, for example, S1, S2, S3…Sm, and maps the weighted baseband digital precoding to each baseband channel, and transmits it to each antenna, for example, antenna 1, antenna 2, antenna 3…antenna m, through the intermediate radio frequency link, and finally transmits it. The UE side receives the CSI-RS, completes the CSI measurement according to the CSI-RS, and feeds back the measurement information such as precoding matrix indication (PMI), channel quality indicator (CQI), rank indication (RI) to the base station. m

[0061] This measurement scheme is a conventional scheme of the DBF system, and the HBF system cannot support this scheme. In this scheme, DBF needs 1 data channel / RF link to drive one antenna, and when the number of antennas is large, the number of required RF links also increases sharply, and the data channel contains expensive intermediate radio devices, which increases the cost of the entire system. In addition, the increase in the number of data channels also requires an increase in the dimension of signal processing, resulting in a significant increase in computational complexity and energy consumption.

[0062] As shown in Figure 5 , a schematic diagram of beam domain CSI measurement based on HBF system is shown. The base station generates CSI-RS and adjusts the weight of the phase shifter to form an analog beam. After the CSI-RS is shaped by the HBF, it is transmitted to the UE. The UE performs CSI measurement on the beamformed reference signal and feeds back to the base station. ​

[0063] The measurement scheme can only complete partial channel CSI measurement although it considers the beam domain measurement of the HBF system. Compared with the full channel CSI measurement scheme, when only partial channel CSI information is available, the beamforming of the base station cannot accurately aim at the UE, which causes the reception signal-to-noise ratio at the UE side to decrease and the UE experience rate to decrease. In addition, when multi-user communication is performed, because the CSI measurement of each user is inaccurate, the multi-user interference cancellation algorithm of the base station is poor in effect, which also causes the average rate of multi-user communication to decrease.

[0064] At present, the discussion on HBF is still very limited, so how to implement channel measurement under the HBF architecture becomes a problem to be solved.

[0065] Therefore, an embodiment of the present application proposes a channel measurement method, which can implement full channel CSI measurement under the HBF architecture.

[0066] As shown in Figure 6 , an architecture example diagram of a hybrid beamforming technology to which an embodiment of the present application is applicable is shown. In Figure 6 , each antenna port in N×M antenna ports of a network device is connected with each radio frequency link in N radio frequency links, each radio frequency link is connected with each antenna through a phase shifter, and each antenna is connected with N phase shifters.

[0067] As shown in Figure 7 , a schematic interaction flowchart of a reference signal transmission method 700 of an embodiment of the present application is shown. Figure 7 The method is shown by taking a network device and a terminal device as the execution subject of the interaction as an example, but the present application does not limit the execution subject of the interaction. For example, Figure 7 The network device in the method can also be a chip, a chip system, or a processor supporting the network device to implement the method, and can also be a logic module or software capable of implementing all or part of the network device functions; Figure 7 The terminal device in the method can also be a chip, a chip system, or a processor supporting the terminal device to implement the method, and can also be a logic module or software capable of implementing all or part of the terminal device functions.

[0068] 710, the network device outputs N×M reference signals to the terminal device using N×M antenna ports on N×M resource elements (REs), the N×M reference signals correspond to the N×M REs one-to-one, each antenna port in the N×M antenna ports is connected with each radio frequency link in N radio frequency links, and the N×M reference signals are used to measure the downlink channel information of the N×M antenna ports, wherein N and M are positive integers. The N×M antenna ports are the antenna ports corresponding to all the transmitting antennas of the network device.

[0069] It should be understood that when a network device outputs one of the N×M reference signals to a terminal device using N×M antenna ports in one of the N×M REs, the network device uses the N×M antenna ports to simultaneously output the reference signal to the terminal device. The network device can measure the downlink channel information corresponding to the N×M antenna ports using the N×M reference signals, thereby improving the accuracy of the channel measurement and the capacity of the system.

[0070] Exemplarily, the reference signal may be a channel state information reference signal, ie, a CSI-RS, or may be other reference signals.

[0071] The reference signal sent by the network device to the terminal device is a reference signal after weighted processing. Specifically, the network device can superimpose the orthogonal cover codes (OCC) matrix w OCC To achieve this, weight the reference signal sent in each RE w OCC A column vector in the OCC matrix w OCC It is obtained by calculating the frequency domain weight and time domain weight. The frequency domain weight is realized by digital channel weighting, and the time domain weight is realized by phase shifter weighting.

[0072] Specifically, the design rules of the OCC matrix used by the reference signal of each antenna port include: P,f =[w P,f (0)w P,f (1) …w P,f (Kf-1)] represents the weight vector of the reference signal output by Kf adjacent REs in the frequency domain at port P, w P,t =[w P,t (0) w P,t (1) …w P,t (Kt-1)] represents the weight vector of the reference signal output by Kt adjacent REs in the time domain at port P, where Kf and Kt are positive integers. In order to ensure normal demodulation of the terminal equipment, any two w P,f are mutually orthogonal. Similarly, any two w P,t are also orthogonal to each other. Then the weight vector of the reference signal output by antenna port P at all REs is w P,f and w P,t The value of is generally defined by the protocol. If it exceeds the protocol definition, you can design it yourself. Represents the Kronecker product operation.

[0073] For example, N×M REs can be divided into M groups of REs, each group of REs occupies N subcarriers and one symbol, and the weight w of the reference signal output on the nth RE of the mth group ism×N+n It can be expressed by the following formula (1):

[0074]

[0075] Among them, w m×N+n is an N×M dimensional vector, is an N×M dimensional vector, a m,n,i One a m,n,i Equal to 1, the rest a m,n,i Equal to 0, 0≤m≤M-1, 0≤n≤N-1, 0≤i≤N-1. When w m×N+n When is an N×M-dimensional column vector, is an N×M-dimensional column vector.

[0076] For different N×M REs, the weights w of different reference signals sent in different REs are m×N+n Specifically, when m is constant, the vectors [a m,n,0 ,…,a m,n,i ,…,a m,n,N-1 ] are orthogonal; or, when n is constant, the vectors corresponding to different values ​​of m They are orthogonal.

[0077] For example, N×M REs may occupy N subcarriers and M symbols. For example, N=2, M=4, as Figure 8 Figure 1 shows a schematic diagram of the frequency and time domains occupied by 8 REs, where the horizontal axis is the time domain interval and the vertical axis is the frequency domain interval. The 8 reference signals are mapped one-to-one to 8 REs corresponding to 4 adjacent symbols and 2 adjacent subcarriers. The 8 REs include RE0, RE1, RE2, RE3, RE4, RE5, RE6, and RE7. RE0 and RE1 occupy the same symbol and 2 adjacent subcarriers, RE2 and RE3 occupy the same symbol and 2 adjacent subcarriers, RE4 and RE5 occupy the same symbol and 2 adjacent subcarriers, and RE6 and RE7 occupy the same symbol and 2 adjacent subcarriers.

[0078] Exemplarily, the N×M REs can also occupy N×M symbols and one subcarrier. Alternatively, the N×M REs can also occupy one symbol and N×M subcarriers. It can also be understood that the network device can realize the mapping of the reference signal through different orthogonal combination modes, that is, through the combination of frequency division multiplexing (FDM), time division multiplexing (TDM), and code division multiplexing (CDM). The embodiments of the present application do not make specific limitations on this.

[0079] Optionally, the weight used by the network device when weighting the reference signal by using the OCC matrix can be agreed by the network device and the terminal device in advance, or be specified in the wireless communication protocol, or be determined by the device itself and notified to the terminal device, of course, the weight can also be determined through other manners, and the embodiments of the present application do not make specific limitations.

[0080] 720, the terminal device receives N×M reference signals output by N×M antenna ports of the network device at N×M REs. Specifically, the signals received by the terminal device at the N×M REs can be represented as Y=[y0,y1,y2,…y N×M-1 ] respectively.

[0081] 730, the terminal device determines the downlink channel information of the N×M antenna ports according to the received N×M reference signals.

[0082] Let the channel from the N×M antenna ports to the terminal device be H=[h0,h1,h2,…,h N×M-1 ], h k is the channel from the kth antenna port to the terminal device, and k is an integer in [0, N×M-1]. Then the signals received by the terminal device at the N×M REs can be represented by the following formula (2):

[0083] Y=HW OCC S+N (2)

[0084] wherein, S0、S1、…、S N×M-1 are N×M reference signals respectively transmitted at N×M REs; w OCC =[w0,w1,…,w N×M-1 ], w0,w1,…,w N×M-1 (w m×N+n ) are weights of the reference signals transmitted at the N×M REs, and w0,w1,…,w N×M-1are column vectors with N*M dimensions; N is the noise of the terminal device receiving the reference signals on the N*M REs, N=[n0, n1, …, n N×M-1 ].

[0085] Here, after the terminal device knows the CSI-RS configuration of the N*M reference signals, the terminal device can know the OCC matrix w OCC used by the network device, and the terminal device also knows the N*M reference signals sent by the network device on the N*M REs, and therefore, the terminal device can perform corresponding de-OCC coding to solve the channel H.

[0086] Specifically, the terminal device can solve the channel H corresponding to the N*M antenna ports according to the following formula (3).

[0087]

[0088] 740, after the terminal device solves the channel, the terminal device quantizes the channel and feeds back the quantized channel information to the terminal device. Specifically, the terminal device sends the downlink channel information of the N*M antenna ports to the network device.

[0089] 750, the network device receives the downlink channel information of the N*M antenna ports sent / feedback by the terminal device.

[0090] Since the analog part is implemented by a phase shifter under the HBF architecture, the phase shifter will have non-ideal factors and will deviate from the phase shifter. In order to improve the accuracy of channel measurement, the channel information fed back by the terminal device needs to be corrected for non-ideal factors. Optionally, the network device can correct the downlink channel information sent by the terminal device.

[0091] Suppose the channel information fed back by the terminal device after quantizing the channel is W pmi , W pmi is a column vector with Rank*N*M dimensions, and Rank is the rank of the feedback. The network device will further correct the received feedback information, and the specific correction method is as shown in formula (4):

[0092] W′ pmi = W pmi *W corr (4)

[0093] Where W′ pmi is the corrected channel information, and W corr is the corrected weight.

[0094] In the embodiments of the present application, the network device can further improve the accuracy of channel measurement by correcting the channel information fed back by the terminal device.

[0095] Optionally, in the embodiment of the present application, the device that outputs N×M reference signals may also be a terminal device, and the device that receives the N×M reference signals output by the N×M antenna ports may also be a network device / base station. In this case, the measured channel information is uplink channel information. Optionally, in the embodiment of the present application, the device that outputs N×M reference signals and the device that receives the N×M reference signals output by the N×M antenna ports may both be a terminal device or a network device. In this case, the measured channel information does not need to be distinguished as uplink channel information or downlink channel information.

[0096] In the technical solution provided in the embodiment of the present application, under the HBF architecture (the number of RF chains is much smaller than the number of antenna ports), the network device (base station) sends N×M reference signals to the terminal device through N×M antenna ports, which can measure the downlink channels corresponding to the N×M antenna ports, thereby obtaining CSI information of the entire channel.

[0097] The following describes the embodiments of the present application in more detail through specific implementation methods.

[0098] Implementation method 1:

[0099] Take the HBF architecture as an example, which includes 2 RF chains and 8 antenna ports, that is, N = 2, M = 4. Each of the 8 antenna ports is connected to each of the 2 RF chains, each RF chain is connected to each antenna through a phase shifter, and each antenna port is connected to 2 phase shifters.

[0100] Step 1: Sending of reference signal.

[0101] In order to measure the channel information of 8 antennas, the network device uses 8 antenna ports in 8 REs to output 8 reference signals, such as CSI-RS, to the terminal device. The network device can map the 8 reference signals to Figure 8 In the eight REs shown, each occupies two subcarriers and four symbols. RE0 and RE1 form a group of REs, RE2 and RE3 form a group of REs, RE4 and RE5 form a group of REs, and RE6 and RE7 form a group of REs. To obtain channel information for eight antenna ports, network equipment can use 8×CDM on the eight REs. This involves mapping eight reference signals to the eight REs and then performing time division multiplexing (TDM) on the eight REs simultaneously, thereby transmitting reference signals for all eight ports.

[0102] These 8 REs need to stack a total of 8×8 dimensional OCC matrix w OCC , weight w for the reference signal sent in each RE OCC The time domain weights and frequency domain weights used by the reference signal output at each antenna port are shown in Table 1.f (0) w f (1)] the weight of the reference signal corresponding to the two REs transmitted in the frequency domain adjacent to each other, [w t (0) w t (1) w t (2) w t (3)] the weight of the reference signal corresponding to the two REs transmitted in the time domain adjacent to each other.

[0103] Table 1 Time domain weight and frequency domain weight of the reference signal output by 8 antenna ports

[0104] Antenna port number [[w f (0) w f (1)]]]> [[w t (0) w t (1) w t (2) w t (3)]]]> 0 [+1 +1] [+1 +1 +1 +1] 1 [+1 -1] [+1 +1 +1 +1] 2 [+1 +1] [+1 -1 +1 -1] 3 [+1 -1] [+1 -1 +1 -1] 4 [+1 +1] [+1 +1 -1 -1] 5 [+1 -1] [+1 +1 -1 -1] 6 [+1 +1] [+1 -1 -1 +1] 7 [+1 -1] [+1 -1 -1 +1]

[0105] Table 2 shows the OCC code used by 8 reference signals output by 8 antenna ports and 8 REs. When implementing the OCC code, it is implemented by the digital channel weight and the phase shifter weight together.

[0106] Table 2 OCC code corresponding to 8 antenna ports and 8 REs

[0107]

[0108]

[0109] Let RE0 / RE1 correspond to time t0, RE2 / RE3 correspond to time t1, RE4 / RE5 correspond to time t2, RE6 / RE7 correspond to time t3, and let the phase shifters corresponding to antenna port 0, antenna port 1, antenna port 2, antenna port 3, antenna port 4, antenna port 5, antenna port 6, and antenna port 7 be phase shifter 0t0 and phase shifter 1t0, phase shifter 0t1 and phase shifter 1t1, phase shifter 0t2 and phase shifter 1t2, phase shifter 0t3 and phase shifter 1t3, phase shifter 0t4 and phase shifter 1t4, phase shifter 0t5 and phase shifter 1t5, phase shifter 0t6 and phase shifter 1t6, and phase shifter 0t7 and phase shifter 1t7, respectively, wherein phase shifter ptq represents the phase shifter connected to the qth antenna port by the pth radio frequency link / digital channel, then:

[0110] (1) At t0 moment: phase shifter 0t0, phase shifter 0t1, phase shifter 0t2, phase shifter 0t3, phase shifter 0t4, phase shifter 0t5, phase shifter 0t6, phase shifter 0t7, the corresponding phase is [0°, 0°, 0°, 0°, 0°, 0°, 0°, 0°]; phase shifter 1t0, phase shifter 1t1, phase shifter 1t2, phase shifter 1t3, phase shifter 1t4, phase shifter 1t5, phase shifter 1t6, phase shifter 1t7, the corresponding phase is [0°, 180°, 0°, 180°, 0°, 180°, 0°, 180°]; and the digital channel weight on RE0 is [1 0], the digital channel weight on RE1 is [0 1].

[0111] Thus, in formula (1), 0≤n≤1, 0≤m≤3, when m=0, n=0, the weight of the reference signal S0 sent by RE0 using 8 antenna ports is:

[0112]

[0113] When m=0, n=1, the weight of the reference signal S1 sent by RE1 using 8 antenna ports is:

[0114]

[0115] It can be seen that the weight of the reference signal sent by RE0 and RE1 matches the weight in table 2.

[0116] (2) At t1 moment: phase shifter 0t0, phase shifter 0t1, phase shifter 0t2, phase shifter 0t3, phase shifter 0t4, phase shifter 0t5, phase shifter 0t6, phase shifter 0t7, the corresponding phase is [0°, 0°, 180°, 180°, 0°, 0°, 180°, 180°]; phase shifter 1t0, phase shifter 1t1, phase shifter 1t2, phase shifter 1t3, phase shifter 1t4, phase shifter 1t5, phase shifter 1t6, phase shifter 1t7, the corresponding phase is [0°, 180°, 180°, 0°, 0°, 180°, 180°, 0°]; and the digital channel weight on RE2 is [1 0], the digital channel weight on RE3 is [0 1].

[0117] Thus, when m=1, n=0, the weight of the reference signal S2 sent by RE2 using 8 antenna ports is:

[0118] When m=1, n=1, the weight of the reference signal S3 sent by RE3 using 8 antenna ports is:

[0119]

[0120] It can be seen that the weight values of the reference signals sent by RE2 and RE3 match the weight values in Table 2.

[0121] (3) At time t2: phase shifter 0t0, phase shifter 0t1, phase shifter 0t2, phase shifter 0t3, phase shifter 0t4, phase shifter 0t5, phase shifter 0t6, phase shifter 0t7, and the corresponding phases are [0°, 0°, 0°, 0°, 180°, 180°, 180°, 180°]; phase shifter 1t0, phase shifter 1t1, phase shifter 1t2, phase shifter 1t3, phase shifter 1t4, phase shifter 1t5, phase shifter 1t6, phase shifter 1t7, and the corresponding phases are [0°, 180°, 0°, 180°, 180°, 0°, 180°, 0°]; and the digital channel weight value on RE4 is [1 0], and the digital channel weight value on RE5 is [0 1].

[0122] Thus, when m = 2 and n = 0, the weight value of the reference signal S4 sent by RE4 using 8 antenna ports is:

[0123] When m = 2 and n = 1, the weight value of the reference signal S5 sent by RE5 using 8 antenna ports is:

[0124]

[0125] It can be seen that the weight values of the reference signals sent by RE4 and RE5 match the weight values in Table 2.

[0126] (4) At time t3: phase shifter 0t0, phase shifter 0t1, phase shifter 0t2, phase shifter 0t3, phase shifter 0t4, phase shifter 0t5, phase shifter 0t6, phase shifter 0t7, and the corresponding phases are [0°, 0°, 180°, 180°, 180°, 180°, 0°, 0°]; phase shifter 1t0, phase shifter 1t1, phase shifter 1t2, phase shifter 1t3, phase shifter 1t4, phase shifter 1t5, phase shifter 1t6, phase shifter 1t7, and the corresponding phases are [0°, 180°, 180°, 0°, 180°, 0°, 0°, 180°]; and the digital channel weight value on RE6 is [1 0], and the digital channel weight value on RE7 is [0 1].

[0127] Thus, when m = 3 and n = 0, the weight value of the reference signal S6 sent by RE6 using 8 antenna ports is:

[0128] When m = 3 and n = 1, the weight value of the reference signal S7 sent by RE7 using 8 antenna ports is:

[0129]

[0130] It can be seen that the weight values of the reference signals sent by RE6 and RE7 match the weight values in Table 2.

[0131] It should be understood that w OCC The real matrix values are defined by the protocol, which can be shared by the network device and the terminal device. Here, only an example is given. The phase adjustment of the phase shifter is also only an example of one implementation. In the embodiments of the present application, it is assumed that the OCC code corresponds to 1, and the phase of the phase shifter is 0°. If the OCC code corresponds to -1, the phase of the phase shifter is 180°. However, other implementations are also equivalent, such as the OCC code corresponding to 1, and the phase of the phase shifter is 180°; the OCC code corresponding to -1, and the phase of the phase shifter is 0°. The present application does not limit this.

[0132] Step two: The terminal device receives the eight reference signals output by the eight antenna ports of the network device on the eight REs; and determines the downlink channel information from the eight antenna ports to the terminal device according to the received reference signals.

[0133] It is assumed that the number of receiving antennas of the terminal device is 2, and the channel from the eight antenna ports to the terminal device is H = [h0, h1, h2, h3, h4, h5, h6, h7], where H is a 2x8 matrix, h k is a 2x1 matrix, k = 0, 1, 2, …, 7, and h k represents the channel between the kth antenna port and the receiving antenna. The signals received by the terminal device on RE0, RE1, RE2, RE3, RE4, RE5, RE6, and RE7 are Y = [y0, y1, y2, y3, y4, y5, y6, y7], where y k is a 2x1 matrix, k = 0, 1, 2, …, 7. It is assumed that the weight values corresponding to the phase shifters 0t0, 0t1, 0t2, 0t3, 0t4, 0t5, 0t6, and 0t7 at times t0, t1, t2, and t3 are and wherein and are 8-dimensional column vectors; it is assumed that the weight values corresponding to the phase shifters 1t0, 1t1, 1t2, 1t3, 1t4, 1t5, 1t6, and 1t7 at times t0, t1, t2, and t3 are and wherein and are 8-dimensional column vectors. The weight values of the reference signals sent on RE0, RE1, RE2, RE3, RE4, RE5, RE6, and RE7 are respectively:

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142] terminal device knows w OCC = [w0, w1, w2, w3, w4, w5, w6, w7], S0, S1, …, S7 are respectively 8 reference signals sent on RE0, RE1, RE2, RE3, RE4, RE5, RE6 and RE7. Then, the terminal device can solve the channel H = [h0, h1, h2, h3, h4, h5, h6, h7] according to the known w OCC and S, the received Y and the above formula (2).

[0143] Step three: the terminal device sends the downlink channel information of the 8 antenna ports to the network device. Specifically, after the terminal device solves the channel H, the terminal device quantizes the channel H to obtain the channel information (which can be denoted as W pmi ), and then the terminal device feeds back W pmi to the network device.

[0144] Step four: the network device receives the downlink channel information of the 8 antenna ports sent / feedback by the terminal device. Optionally, the network device can also correct the W pmi feedback by the terminal device according to the above formula (4).

[0145] Implementation mode two:

[0146] Take the HBF architecture including 2 RF links and 4 antenna ports as an example, that is, N = 2, M = 2. Each of the 4 antenna ports is connected with each of the 2 RF links, each RF link is connected with each antenna through a phase shifter, and each antenna port is connected with 2 phase shifters.

[0147] Step one: sending of reference signals.

[0148] In order to measure the channel information of the four antennas, the network device uses four antenna ports in four REs to output four reference signals, such as CSI-RS, to the terminal device. Figure 9 As shown in FIG, a schematic diagram of the frequency domain and time domain occupied by 4 REs is shown, where the horizontal axis is the time domain interval and the vertical axis is the frequency domain interval. The network device can map the 4 reference signals to the following Figure 9 In the four REs shown, each occupies two subcarriers and two symbols. RE0 and RE1 form a group of REs, and RE2 and RE3 form another group of REs. To obtain channel information for four antenna ports, network equipment can use 4×CDM on the four REs. This involves mapping four reference signals to the four REs and then performing time division multiplexing (TDM) on the four REs simultaneously, thereby transmitting reference signals for all four ports.

[0149] These four REs need to superimpose a total of 4×4 dimensional OCC matrix w OCC , weight w for the reference signal sent in each RE OCC The time domain weights and frequency domain weights used by the reference signal output at each antenna port are shown in Table 3. f (0) w f (1)] corresponds to the weight of the reference signal sent by two adjacent REs in the frequency domain, [w t (0) w t (1)] corresponds to the weight of the reference signal sent by two adjacent REs in the time domain.

[0150] Table 3 Time domain weights and frequency domain weights of the reference signals output by the four antenna ports

[0151] Antenna port number [[w f (0) w f (1)]]]> [[w t (0) w t (1)]]]> 0 [+1 +1] [+1 +1] 1 [+1 -1] [+1 +1] 2 [+1 +1] [+1 -1] 3 [+1 -1] [+1 -1]

[0152] Table 4 shows the OCC codes used by the four reference signals output by four REs using four antenna ports. The OCC codes are implemented by combining digital channel weights and phase shifter weights.

[0153] Table 4 OCC codes corresponding to 4 antenna ports and 4 REs

[0154]

[0155] The time corresponding to RE0 / RE1 is t0, and the time corresponding to RE2 / RE3 is t1. The phase shifters corresponding to antenna port 0, antenna port 1, antenna port 2, and antenna port 3 are phase shifter 0t0 and phase shifter 1t0, phase shifter 0t1 and phase shifter 1t1, phase shifter 0t2 and phase shifter 1t2, and phase shifter 0t3 and phase shifter 1t3, respectively. Phase shifter ptq represents the phase shifter connected to the qth antenna port by the pth RF link / digital channel. Then:

[0156] (1) At time t0: phase shifter 0t0, phase shifter 0t1, phase shifter 0t2, phase shifter 0t3, the corresponding phase is [0°, 0°, 0°, 0°], phase shifter 1t0, phase shifter 1t1, phase shifter 1t2, phase shifter 1t3, the corresponding phase is [0°, 180°, 0°, 180°], and the digital channel weight on RE0 is [1 0], and the digital channel weight on RE1 is [0 1].

[0157] Thus, in formula (1), 0≤n≤1, 0≤m≤1, when m=0, n=0, the weight of the reference signal S0 sent by the 4 antenna ports of RE0 is:

[0158]

[0159] When m=0, n=1, the weight of the reference signal S1 sent by the 4 antenna ports of RE1 is:

[0160]

[0161] It can be seen that the weight of the reference signal sent by RE0 and RE1 matches the weight in Table 4.

[0162] (2) At time t1: phase shifter 0t0, phase shifter 0t1, phase shifter 0t2, phase shifter 0t3, the corresponding phase is [0°, 0°, 180°, 180°]; phase shifter 1t0, phase shifter 1t1, phase shifter 1t2, phase shifter 1t3, the corresponding phase is [0°, 180°, 180°, 0°]; and the digital channel weight on RE2 is [1 0], and the digital channel weight on RE3 is [0 1].

[0163] Thus, when m=1, n=0, the weight of the reference signal S2 sent by the 4 antenna ports of RE2 is:

[0164] When m=1, n=1, the weight of the reference signal S3 sent by the 4 antenna ports of RE3 is:

[0165]

[0166] It can be seen that the weight of the reference signal sent by RE2 and RE3 matches the weight in Table 4.

[0167] Step two: the terminal device receives the 4 reference signals output by the 4 antenna ports of the network device; and determines the downlink channel information from the 4 antenna ports to the terminal device according to the received reference signals.

[0168] Assume that the number of receiving antennas of the terminal device is 2, and the channel from 4 antenna ports to the terminal device is H = [h0, h1, h2, h3], where H is a 2 x 4 matrix, h k is a 2 x 1 matrix, k = 0, 1, 2, 3, and h k represents the channel between the kth antenna port and the receiving antenna. The signals received by the terminal device at RE0, RE1, RE2, and RE3 are Y = [y0, y1, y2, y3], where y k is a 2 x 1 matrix, k = 0, 1, 2, 3. Assume that the weights corresponding to phase shifters 0t0, 0t1, 0t2, and 0t3 at times t0 and t1 are and wherein and are 4-dimensional column vectors; assume that the weights corresponding to phase shifters 1t0, 1t1, 1t2, and 1t3 at times t0 and t1 are and wherein and are 4-dimensional column vectors. Then, the weights corresponding to the reference signals sent at RE0, RE1, RE2, and RE3 are respectively:

[0169]

[0170]

[0171]

[0172]

[0173] The terminal device knows w OCC = [w0, w1, w2, w3], S0, S1, S2, and S3 are the 4 reference signals sent at RE0, RE1, RE2, and RE3 respectively. Then, the terminal device can solve the channel H = [h0, h1, h2, h3] according to the known w OCC , the received Y, and the above formula (2).

[0174] Step three: The terminal device sends the downlink channel information of the 4 antenna ports to the network device. Specifically, after solving the channel H, the terminal device quantizes the channel H to obtain the channel information (which can be denoted as W pmi ), and then feeds back W pmi to the network device.

[0175] Step four: The network device receives the downlink channel information of the 4 antenna ports sent / feedback by the terminal device. Optionally, the network device can also solve the channel H according to the above formula (4) and the Wpmi correction is made.

[0176] The embodiment of the application provides a communication device, such as Figure 10 As shown in the figure, a schematic block diagram of a communication device 1000 is shown. The device can be applied to the network equipment in the embodiment of the application. The communication device 1000 comprises:

[0177] The sending module 1010 is configured to output N×M reference signals by using N×M resource elements (REs) and N×M antenna ports, the N×M reference signals correspond to the N×M REs one by one, each of the N×M antenna ports is connected with each of N radio frequency (RF) links, and the N×M reference signals are used to measure downlink channel information of the N×M antenna ports, wherein N and M are positive integers.

[0178] The N×M REs comprise M groups of REs, each group of REs comprises N REs, each group of REs occupies N subcarriers and one symbol, and the weight w m×N+n of the reference signal output on the nth RE of the mth group is:

[0179]

[0180] wherein w m×N+n is an N×M-dimensional vector, is an N×M-dimensional vector, a m,n,i each a m,n,i is equal to 1, and the remaining a m,n,i are equal to 0, 0≤m≤M-1, 0≤n≤N-1, and 0≤i≤N-1.

[0181] The receiving module 1020 is configured to receive the downlink channel information of the N×M antenna ports.

[0182] Optionally, when the value of m is certain, the vectors [a m,n,0 ,…,a m,n,i ,…,a m,n,N-1 ] corresponding to different values of n are orthogonal; or, when the value of n is certain, the vectors [a ,…,a are orthogonal.

[0183] Optionally, the N×M REs occupy N subcarriers and M symbols.

[0184] Optionally, N is equal to 2, M is equal to 4, 0≤n≤1, and 0≤m≤3.

[0185] When m=0 and n=0,

[0186] When m=0 and n=1,

[0187] when m = 1, n = 0,

[0188] when m = 1, n = 1,

[0189] when m = 2, n = 0,

[0190] when m = 2, n = 1,

[0191] when m = 3, n = 0,

[0192] when m = 3, n = 1, wherein w0, w1, w2, w3, w4, w5, w6 and w7 are weight values corresponding to 8 reference signals output by 8 antenna ports respectively.

[0193] Optionally, N is equal to 2, M is equal to 2, 0≤n≤1, 0≤m≤1.

[0194] when m = 0, n = 0,

[0195] when m = 0, n = 1,

[0196] when m = 1, n = 0,

[0197] when m = 1, n = 1,

[0198] wherein w0, w1, w2 and w3 are weight values corresponding to 4 reference signals output by 4 antenna ports respectively.

[0199] Optionally, the apparatus 1000 further comprises a processing module 1030, configured to: correct the downlink channel information.

[0200] An embodiment of the present application provides a communication device 1100, as shown in the schematic block diagram of the communication device 1100. Figure 11 An embodiment of the present application provides a communication device 1100, as shown in the schematic block diagram of the communication device 1100.

[0201] The communication device 1100 comprises a processor 1110 and a transceiver 1120, wherein the transceiver 1120 is configured to receive computer code or instructions and transmit the computer code or instructions to the processor 1110, and the processor 1110 is configured to execute the computer code or instructions to implement the method in the embodiment of the present application. The communication device can be a terminal device or a network device in the embodiment of the present application.

[0202] The processor 1110 described above can be an integrated circuit chip with a signal processing capability. In the implementation process, each step of the method embodiment described above can be completed by the integrated logic circuit of hardware in the processor or the instruction in the form of software. The processor described above can be a general processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. Each method, step and logic block diagram disclosed in the embodiment of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in combination with the embodiment of the present application can be directly embodied as a hardware code processor for execution, or a combination of hardware and software modules in the code processor for execution. The software module can be located in a random access memory, a flash memory, a read only memory, a programmable read only memory or an electrically erasable programmable memory, a register or other mature storage medium in the art. The storage medium is located in the memory, and the processor reads the information in the memory and combines the hardware to complete the steps of the above method.

[0203] Optionally, the embodiment of the present application further provides a communication device, which comprises an input and output interface and a logic circuit, the input and output interface is used for acquiring input information and / or output information; the logic circuit is used for executing the method in any method embodiment described above, processing according to the input information and / or generating the output information.

[0204] The embodiment of the present application further provides a computer readable storage medium, which has a computer program for implementing the method in the method embodiment described above. When the computer program runs on the computer, the computer can implement the method in the method embodiment described above.

[0205] The embodiment of the present application further provides a computer program product, which comprises computer program code, when the computer program code runs on the computer, the method in the method embodiment described above is executed.

[0206] The embodiment of the present application further provides a chip, which comprises a processor, the processor is connected with a memory, the memory is used for storing a computer program, and the processor is used for executing the computer program stored in the memory, so that the chip executes the method in the method embodiment described above.

[0207] In addition, the term "and / or" in the present application is only used to describe associated objects, and can represent three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects; the term "at least one" in the present application can represent "one" and "two or more", for example, A, B and C, which can represent the following seven cases: A exists alone, B exists alone, C exists alone, A and B exist simultaneously, A and C exist simultaneously, C and B exist simultaneously, and A, B and C exist simultaneously.

[0208] Those skilled in the art can clearly understand that the units and algorithm steps of each example described in combination with the embodiments disclosed in the present application can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0209] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0210] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be realized by other ways. For example, the device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0211] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0212] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit.

[0213] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the present application that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of software products. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the embodiments of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0214] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for transmitting a reference signal, characterized in that: include: Outputting N×M reference signals using N×M antenna ports in N×M resource elements (REs), wherein the N×M reference signals correspond one-to-one to the N×M REs, each of the N×M antenna ports is connected to each of the N radio frequency links, and the N×M reference signals are used to measure downlink channel information of the N×M antenna ports, where N and M are positive integers; The N×M REs include M groups of REs, each group of REs includes N REs, each group of REs occupies N subcarriers and one symbol, and the weight w of the reference signal output on the nth RE of the mth group is m×N+n for: Among them, w m×N+n is an N×M dimensional vector, is an N×M dimensional vector, a m,n,i One a m,n,i Equal to 1, the rest a m,n,i Equal to 0, 0≤m≤M-1, 0≤n≤N-1, 0≤i≤N-1; Receive downlink channel information of the N×M antenna ports.

2. The method according to claim 1, characterized in that When m takes a certain value, the vectors corresponding to different values ​​of n [a m,n,0 ,…,a m,n,i ,…,a m,n,N-1 ] are orthogonal; or, When n takes a certain value, the vector corresponding to different values ​​of m They are orthogonal.

3. The method according to claim 1 or 2, characterized in that The N×M REs occupy N subcarriers and M symbols.

4. The method according to claim 1 or 2, characterized in that N=2, M=4, 0≤n≤1, 0≤m≤3; When m=0, n=0, When m=0, n=1, When m=1, n=0, When m=1, n=1, When m=2, n=0, When m=2, n=1, When m=3, n=0, When m=3, n=1, Among them, w0, w1, w2, w3, w4, w5, w6 and w7 are the weights corresponding to the eight reference signals output by the eight antenna ports.

5. The method according to claim 1 or 2, characterized in that N=2, M=2, 0≤n≤1, 0≤m≤1; When m=0, n=0, When m=0, n=1, When m=1, n=0, When m=1, n=1, Among them, w0, w1, w2 and w3 are the weights corresponding to the four reference signals output by the four antenna ports.

6. The method according to claim 1 or 2, characterized in that The method further comprises: The downlink channel information is modified.

7. A communication device, characterized in that: include: a transmitting module, configured to output N×M reference signals using N×M antenna ports on N×M resource elements (REs), where the N×M reference signals correspond one-to-one to the N×M REs, each of the N×M antenna ports is connected to each of the N radio frequency links, and the N×M reference signals are used to measure downlink channel information of the N×M antenna ports, where N and M are positive integers; The N×M REs include M groups of REs, each group of REs includes N REs, each group of REs occupies N subcarriers and one symbol, and the weight w of the reference signal output on the nth RE of the mth group is m×N+n for: Among them, w m×N+n is an N×M dimensional vector, is an N×M dimensional vector, a m,n,i One a m,n,i Equal to 1, the rest a m,n,i Equal to 0, 0≤m≤M-1, 0≤n≤N-1, 0≤i≤N-1; The receiving module is configured to receive downlink channel information of the N×M antenna ports.

8. The device according to claim 7, characterized in that When m takes a certain value, the vectors corresponding to different values ​​of n [a m,n,0 ,…,a m,n,i ,…,a m,n,N-1 ] are orthogonal; or, When n takes a certain value, the vector corresponding to different values ​​of m They are orthogonal.

9. The device according to claim 7 or 8, characterized in that The N×M REs occupy N subcarriers and M symbols.

10. The device according to claim 7 or 8, characterized in that N is equal to 2, M is equal to 4, 0≤n≤1, 0≤m≤3; When m=0, n=0, When m=0, n=1, When m=1, n=0, When m=1, n=1, When m=2, n=0, When m=2, n=1, When m=3, n=0, When m=3, n=1, Among them, w0, w1, w2, w3, w4, w5, w6 and w7 are the weights corresponding to the eight reference signals output by the eight antenna ports.

11. The device according to claim 7 or 8, characterized in that N is equal to 2, M is equal to 2, 0≤n≤1, 0≤m≤1; When m=0, n=0, When m=0, n=1, When m=1, n=0, When m=1, n=1, Among them, w0, w1, w2 and w3 are the weights corresponding to the four reference signals output by the four antenna ports.

12. The device according to claim 7 or 8, characterized in that The device further comprises a processing module, wherein the processing module is configured to: The downlink channel information is modified.

13. A communication device, characterized in that: include: A processor and a transceiver, wherein the transceiver is configured to receive computer codes or instructions and transmit the computer codes or instructions to the processor, and the processor executes the computer codes or instructions, according to the method according to any one of claims 1 to 6.

14. A communication device, characterized in that: include: Input and output interfaces and logic circuits; The input and output interface is used to obtain input information and / or output information; The logic circuit is used to execute the method according to any one of claims 1 to 6, and process and / or generate the output information according to the input information.

15. A computer-readable storage medium, characterized in that include: The computer readable medium stores a computer program; When the computer program is run on a computer, the computer is caused to execute the method according to any one of claims 1 to 6.

16. A computer program product, characterized in that The invention comprises a computer program which, when executed, enables the method according to any one of claims 1 to 6 to be implemented.

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