Signal detection method and apparatus, receiver, and computer readable storage medium

Abstract

The present application provides a signal detection method and apparatus for a multiple input and multiple output system, a receiver, and a computer readable storage medium. The method comprises: receiving signals from a number Q of transmitting ports by a number P of receiving ports, P and Q both being positive integers; when a number L is less than or equal to the lower value among P and Q, determining a number J of receiving ports having lower received signal power among the P receiving ports, or a number K of transmitting ports having lower received signal power among the Q transmitting ports, L being the number of space division multiplexing layers of the received signals, J≤P-L and K≤Q-L; determining a degree of power imbalance of each receiving port among the J receiving ports, or a degree of power imbalance of each transmitting port among the K transmitting ports; performing signal detection processing on the received signals, the signal detection processing comprising signal ignore processing.

Description

Signal detection method, device, receiver and computer-readable storage medium

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202311812436.6 filed on December 26, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present application relates to Multiple Input Multiple Output (MIMO) technology in the field of wireless communications, and in particular to a signal detection method, device, receiver, and computer-readable storage medium for a MIMO system. Background Art

[0004] Multiple-Input Multiple-Output (MIMO) is a key technology for improving system capacity and signal transmission quality in wireless communication systems. Its application in physical channels is specified in both the 3GPP and Wi-Fi protocols. Typically, the MIMO specifications in these protocols specify that the transmit power of different antenna ports is equal, meaning the transmit power is balanced. Receivers are also typically designed for this power balance.

[0005] However, in actual wireless communication systems, the signal power of signals sent from different MIMO transmission ports is often unbalanced when they reach the receiver. This is mainly due to the different wireless fading channels experienced between different transmission ports and different receiving antennas in the wireless propagation environment, the non-ideal RF channel of the transmitter or receiver, and the possibility that the signals between some transmission ports and different receiving antennas may be physically blocked.

[0006] The transmitter's signal undergoes precoding during its formation. This precoding process includes precoding modes for a single transmit port, spatial division multiplexing, and transmit diversity. Transmit diversity in 3GPP uses space-frequency block coding (SFBC) based on adjacent subcarriers, while transmit diversity in Wi-Fi uses space-time block coding (STBC) based on adjacent symbols. The receiver must use a detection method tailored to the precoding mode to process the transmitted signal. When the power imbalance between different transmit ports and different receive channels reaches a certain level, continuing to use conventional receiver detection methods designed for power-balanced conditions can affect detection performance.

[0007] Summary of the Invention

[0008] The present application provides a signal detection method, device, receiver, and computer-readable storage medium for a multiple-input multiple-output system.

[0009] On the one hand, an embodiment of the present application provides a signal detection method for a multiple-input multiple-output system, including: receiving signals from Q transmitting ports via P receiving ports, where P and Q are both positive integers; when L is less than or equal to the smaller value of P and Q, determining J receiving ports with smaller received signal power among the P receiving ports or K transmitting ports with smaller received signal power among the Q transmitting ports, where L is the number of spatial division multiplexing layers of the received signal, J≤PL, K≤QL; determining the power imbalance of each receiving port among the J receiving ports or the power imbalance of each transmitting port among the K transmitting ports; performing signal detection processing on the received signal, wherein the signal detection processing includes signal ignoring processing, and the signal ignoring processing includes at least one of the following two: ignoring signals received via receiving ports among the J receiving ports whose power imbalance is greater than a first preset threshold; ignoring signals transmitted by transmitting ports among the K transmitting ports whose power imbalance is greater than a second preset threshold and received by the P receiving ports.

[0010] On the other hand, an embodiment of the present application also provides a signal detection device for a multiple-input multiple-output system, in which signals from Q transmitting ports are received via P receiving ports, where P and Q are both positive integers, and the signal detection device includes: a power comparison module, used to determine J receiving ports with smaller received signal power among the P receiving ports or K transmitting ports with smaller received signal power among the Q transmitting ports, where L is the number of spatial division multiplexing layers of the received signal, J≤PL, K≤QL; an imbalance calculation module, used to determine the power imbalance of each receiving port among the J receiving ports or the power imbalance of each transmitting port among the K transmitting ports; a signal detection processing module, used to perform signal detection processing on the received signal, wherein the signal detection processing includes signal ignoring processing, and the signal ignoring processing includes at least one of the following two: ignoring signals received via receiving ports among the J receiving ports whose power imbalance is greater than a first preset threshold; ignoring signals transmitted by transmitting ports among the K transmitting ports whose power imbalance is greater than a second preset threshold and received by the P receiving ports.

[0011] On the other hand, the present application further provides a receiver, comprising the signal detection device for a multiple-input multiple-output system as described above.

[0012] On the other hand, an embodiment of the present application further provides a computing device, including a processor and a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the signal detection method as described above.

[0013] On the other hand, an embodiment of the present application further provides a computer-readable storage medium, comprising computer-executable instructions. When the computer-executable instructions are executed by one or more processors, the signal detection method as described above is executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG1 is a schematic diagram of the hardware structure of a receiver for a signal detection method for a multiple-input multiple-output system according to an embodiment of the present application;

[0015] FIG2 is a schematic flow chart of a signal detection method for a MIMO system according to an embodiment of the present application;

[0016] 3 is a schematic flowchart of a signal detection method when the precoding mode is transmit diversity and there is redundancy in the transmit port according to another embodiment of the present application;

[0017] FIG4 is a schematic block diagram of the structure of a signal detection device for a MIMO system according to an embodiment of the present application;

[0018] FIG5 is a diagram showing signal detection performance when the precoding mode is transmit diversity according to the signal detection method of an embodiment of the present application;

[0019] FIG6 is a schematic flowchart of a receiver processing a received signal according to an embodiment of the present application. DETAILED DESCRIPTION

[0020] The embodiments of the present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. Furthermore, the following embodiments may be combined and referenced with one another, provided there is no contradiction.

[0022] The method embodiments provided in the embodiments of the present application can be executed in a receiving end device (or referred to as a "receiving end", "receiver", etc.) of a MIMO system. Figure 1 is a hardware structure block diagram of a receiver for a signal detection method for a multi-input multi-output system according to an embodiment of the present application. As shown in Figure 1 , the receiver may include one or more (only one is shown in Figure 1 ) processors 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA) and a memory 104 for storing data, wherein the above-mentioned receiver may also include a transmission device 106 and an input / output device 108 for communication functions. It will be understood by those skilled in the art that the structure shown in Figure 1 is only for illustration and does not limit the structure of the above-mentioned receiver. For example, the receiver may also include more or fewer components than those shown in Figure 1 , or have a configuration different from that shown in Figure 1 .

[0023] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the signal detection method in the embodiment of the present application. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, implements the above-mentioned signal detection method. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories may be connected to the mobile terminal via a network. Examples of the above-mentioned network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0024] The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned network may include a wireless network provided by a communications provider. In one embodiment, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to enable communication with the Internet. In another embodiment, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly. The transmission device 106 may include a transmitting port and / or a receiving port as described below.

[0025] To address the problem of poor detection performance when conventional receiver detection methods are used when the power balance between the transmit port and the receive channel exceeds a threshold, an embodiment of the present application provides a signal detection method for a multiple-input multiple-output system. When the power imbalance between different transmit ports and different receive channels corresponding to the receiver reaches a certain level, the receiver's received signal detection method can be adjusted to resolve the existing problem and improve receiver detection performance. This method can be applied to single-port, spatial division multiplexing, and transmit diversity scenarios under 3GPP NR / LTE-A, and can also be applied to similar scenarios in next-generation wireless communication networks. The transmitter can be a base station (gNB), a relay, or various gateways (APs). It can also be applied to transmit diversity scenarios in wireless network communication technologies, where the transmitter can be a terminal device (STA). The signal detection method can be performed by a receiving device.

[0026] FIG2 is a schematic flow chart of a signal detection method for a MIMO system according to an embodiment of the present application. The method may include the following steps S202 to S208 .

[0027] In step S202 , signals from Q transmitting ports are received via P receiving ports, where P and Q are both positive integers.

[0028] In the embodiment of the present application, the receiving port (i.e., the receiving channel) includes components in the receiver used to track, process, and measure signals, and may be composed of radio components, digital circuits, etc. and dedicated software; the transmitting port (i.e., the transmitting antenna) includes electronic components that have the function of converting radio frequency signal current into spatial electromagnetic waves, and the signal received by the receiving port comes from the transmitting port of the transmitting device.

[0029] In step S204, when L is less than or equal to the smaller value of P and Q, J receiving ports with smaller received signal power among the P receiving ports or K transmitting ports with smaller received signal power among the Q transmitting ports are determined, where L is the number of spatial division multiplexing layers of the received signal, J≤PL, K≤QL.

[0030] Q can be the number of transmitting antenna ports, that is, the number of transmitting ports; P can be the number of receiving antennas, that is, the number of receiving ports.

[0031] L being less than or equal to the smaller value of P and Q means that redundant transmitting and / or receiving ports exist, so it is feasible to ignore signals of certain transmitting and / or receiving ports.

[0032] In an exemplary embodiment, the received signal powers of P receiving ports and Q transmitting ports can be determined in the following manner: for each of the P receiving ports, the sum of the powers of the signals received by the receiving port from the Q transmitting ports is calculated as the received signal power of the receiving port; for each of the Q transmitting ports, the sum of the powers of the signals transmitted by the transmitting port and received by the P receiving ports is calculated as the received signal power of the transmitting port.

[0033] In an exemplary embodiment, the reference signal received power (RSRP) of the received signal may be used as the received signal power. Alternatively, the received signal power of the receiving port and the transmitting port may be determined using other methods, which are not limited herein. For example, the received signal power of the receiving port or the transmitting port may be determined based on the maximum power of the received signal.

[0034] In an exemplary embodiment, when the precoding mode of the received signal is single-port or spatial division multiplexing: determining J receiving ports with smaller received signal power among the P receiving ports in step S204 includes: comparing the received signal powers of the P receiving ports and sorting the P receiving ports in descending order of received signal power; and determining the last J receiving ports in the sorting as the J receiving ports with smaller received signal power among the P receiving ports. Determining K transmitting ports with smaller received signal power among the Q transmitting ports in step S204 includes: comparing the received signal powers of the Q transmitting ports and sorting the Q transmitting ports in descending order of received signal power; and determining the last K transmitting ports in the sorting as the K transmitting ports with smaller received signal power among the Q transmitting ports.

[0035] In another exemplary embodiment, when the precoding mode of the received signal is transmit diversity, L=1, wherein the Q transmitting ports include Q / 2 first-type transmitting ports and Q / 2 second-type transmitting ports, and the mth first-type transmitting port and the mth second-type transmitting port respectively transmit a signal s at the (Q·i+2m-2)th subcarrier. 2m-2 、 Signal s is sent on the (Q·i+2m-1)th subcarrier respectively 2m-1 、 The mth first-category transmit port and the mth second-category transmit port are considered the mth group of transmit ports, where m = 1, ..., Q / 2, and i is a positive integer. Determining the J receive ports with lower received signal power among the P receive ports in step S204 includes: comparing the received signal powers of the P receive ports and sorting the P receive ports in descending order of received signal power; and determining the last J receive ports in the sorting as the J receive ports with lower received signal power among the P receive ports. Determining the K transmit ports with lower received signal power among the Q transmit ports in step S204 includes: for the mth group of transmit ports, when the received signal power of the mth first-category transmit port is greater than the received signal power of the mth second-category transmit port, determining the mth second-category transmit port as one of the K transmit ports; and for the mth group of transmit ports, when the received signal power of the mth second-category transmit port is greater than the received signal power of the mth first-category transmit port, determining the mth first-category transmit port as one of the K transmit ports.

[0036] In step S206 , the power imbalance degree of each receiving port in the J receiving ports or the power imbalance degree of each transmitting port in the K transmitting ports is determined.

[0037] In an exemplary embodiment, determining the power imbalance of each of the J receive ports includes: selecting all or some of the receive ports from the P receive ports, excluding the J receive ports, as comparison receive ports; for each of the J receive ports, calculating a ratio of the received signal power of the receive port to the received signal power of each of the comparison receive ports, and using the smallest ratio as the power imbalance of the receive port. Determining the power imbalance of each of the K transmit ports includes: selecting all or some of the transmit ports, excluding the K transmit ports, from the Q transmit ports, as comparison transmit ports; for each of the K transmit ports, calculating a ratio of the received signal power of the transmit port to the received signal power of each of the comparison transmit ports, and using the smallest ratio as the power imbalance of the transmit port.

[0038] In an exemplary embodiment, when the precoding transmission mode of the received signal is single port or spatial division multiplexing: when determining the power imbalance of each of the J receiving ports, all of the receiving ports except the J receiving ports among the P receiving ports are selected as comparison receiving ports; when determining the power imbalance of each of the K transmitting ports, all of the transmitting ports except the K transmitting ports among the Q transmitting ports are selected as comparison transmitting ports.

[0039] In another exemplary embodiment, when the precoding transmission mode of the received signal is transmit diversity: determining the power imbalance of each of the J receiving ports includes: selecting all receiving ports except the J receiving ports from the P receiving ports as comparison receiving ports.

[0040] Determining the power imbalance of each of the K transmit ports includes: when the mth second-category transmit port is determined to be one of the K transmit ports, calculating a ratio of a received signal power of the mth first-category transmit port to a received signal power of the mth second-category transmit port, as the power imbalance of the transmit port of one of the K transmit ports corresponding to the mth group; and when the mth first-category transmit port is determined to be one of the K transmit ports, calculating a ratio of a received signal power of the mth second-category transmit port to a received signal power of the mth first-category transmit port, as the power imbalance of the transmit port of one of the K transmit ports corresponding to the mth group, where m=1, ..., Q / 2.

[0041] In step S208, signal detection processing is performed on the received signal, wherein the signal detection processing includes signal ignoring processing, and the signal ignoring processing includes at least one of the following two: ignoring a signal received by a receiving port having a power imbalance greater than a first preset threshold among the J receiving ports; and ignoring a signal transmitted by a transmitting port having a power imbalance greater than a second preset threshold among the K transmitting ports and received by the P receiving ports.

[0042] It should be noted that the specific implementation methods of signal ignoring mentioned in this application include but are not limited to: ignoring the signal of the corresponding port, treating it as noise, setting the channel estimation value in the matrix corresponding to the port to zero, or deleting the corresponding port from all ports.

[0043] In the above embodiments, when the power imbalance of the transmitting port or the receiving port exceeds the preset threshold and there is port redundancy (L is less than or equal to the smaller value of P and Q), the signal of the receiving port or the transmitting port whose power imbalance exceeds the preset threshold is ignored when performing received signal detection. This simplifies the channel estimation matrix, reduces processing complexity, reduces or avoids channel estimation errors, and thus improves the performance of received signal detection.

[0044] In an exemplary embodiment, the precoding mode of the received signal is single-port, in which case Q=1, L=1, and a maximum ratio combining (MRC) algorithm is used when performing signal detection processing on the received signal. The signal ignoring processing is as follows: the signal received by the receiving port whose power imbalance among the J receiving ports is greater than a first preset threshold is ignored.

[0045] In another exemplary embodiment, the precoding transmission mode of the received signal is space division multiplexing, and L>1. When performing signal detection processing on the received signal, the minimum mean square error MMSE algorithm or the sphere decoding SD algorithm is adopted, and the signal ignoring processing includes: ignoring the signal received by the receiving port whose power imbalance is greater than the first preset threshold among the J receiving ports; and ignoring the signal transmitted by the transmitting port whose power imbalance is greater than the second preset threshold among the K transmitting ports and received by the P receiving ports.

[0046] In another exemplary embodiment, the precoding transmission mode of the received signal is transmit diversity, and L=1. The signal ignoring processing includes: ignoring the signal received by the receiving port whose power imbalance is greater than a first preset threshold among the J receiving ports; and ignoring the signal transmitted by the transmitting port whose power imbalance is greater than a second preset threshold among the K transmitting ports and received by the P receiving ports, wherein: for the receiving port whose power imbalance is greater than the first preset threshold among the J receiving ports, when performing the signal detection processing on the received signal, a minimum mean-square error (MMSE) algorithm or a sphere decoding (SD) algorithm is adopted; or, for the transmitting port whose power imbalance is greater than the second preset threshold among the K transmitting ports, when performing the signal detection processing on the received signal, a maximum ratio combining (MRC) algorithm is adopted.

[0047] For example, in one example, for the mth (m=1, ..., Q / 2) group of transmit ports:

[0048] When the received signal power of the mth first-category transmitting port is greater than the received signal power of the mth second-category transmitting port and the power imbalance of the mth second-category transmitting port is greater than the second preset threshold, the maximum ratio combining (MRC) algorithm is used in the signal detection process to output As a pair 2m-2 、s 2m-1 a detection result of performing the signal detection processing;

[0049] When the received signal power of the mth second-category transmitting port is greater than the received signal power of the mth first-category transmitting port and the power imbalance of the mth first-category transmitting port is greater than the second preset threshold, the maximum ratio combining (MRC) algorithm is used in the signal detection process, and the output result is expressed as Then Perform symbol transformation to obtain As a pair 2m-2、s 2m-1 The detection result of the signal detection process, wherein:

[0050] in, Express The real part of is multiplied by -1 to obtain the inverse, while the imaginary part remains unchanged; Express The imaginary part of is multiplied by -1 to negate it, while the real part remains unchanged.

[0051] In this embodiment, the precoding mode of the received signal is transmit diversity. When performing signal detection processing on the received signal, an improved MRC detection method is used for the signal transmitted by the transmitting port that meets the preset conditions and received by the receiving port. That is, the detection result of the MRC algorithm is symbol-transformed and used as the final detection result. This improved MRC algorithm has lower processing complexity than the conventional MMSE algorithm, and reduces or eliminates the influence of channel estimation errors, thereby achieving better detection performance than the MMSE detection method.

[0052] In addition, in an embodiment in which the precoding transmission mode is transmit diversity, for a receiving port among the J receiving ports whose power imbalance is less than or equal to a first preset threshold or a transmitting port among the K transmitting ports whose power imbalance is less than or equal to a second preset threshold, when performing the signal detection processing on the received signal, a minimum mean square error (MMSE) algorithm or a sphere decoding (SD) algorithm is used.

[0053] The present application also provides a signal detection device for a multi-input multi-output system, which is used to implement the above-mentioned method embodiments. As used below, the term "module" can be any combination of software, hardware and / or firmware that implements a predetermined function.

[0054] Figure 4 is a block diagram of a signal detection device for a MIMO system according to an embodiment of the present invention. In the MIMO system, signals from Q transmitting ports are received via P receiving ports, where P and Q are both positive integers.

[0055] As shown in FIG. 4 , the signal detection device 40 includes a power comparison module 410 , an imbalance calculation module 420 and a signal detection processing module 430 .

[0056] The power comparison module 410 is configured to determine J receiving ports with smaller received signal power among P receiving ports or K transmitting ports with smaller received signal power among Q transmitting ports, where L is the number of spatial division multiplexing layers of the received signal, J≤PL, K≤QL.

[0057] The imbalance calculation module 420 is configured to determine the power imbalance of each of the J receiving ports or the power imbalance of each of the K transmitting ports.

[0058] The signal detection processing module 430 is configured to perform signal detection processing on the received signal, wherein the signal detection processing is performed on the received signal, wherein the signal detection processing includes signal ignoring processing, and the signal ignoring processing includes at least one of the following two: ignoring the signal received by the receiving port whose power imbalance is greater than the first preset threshold among the J receiving ports; ignoring the signal transmitted by the transmitting port whose power imbalance is greater than the second preset threshold among the K transmitting ports and received by the P receiving ports.

[0059] It should be noted that each of the above modules can be implemented by software, hardware, firmware, or any combination thereof. For example, it can be implemented in the following ways, but is not limited to: all of the above modules are located in the same processor; or the above modules are located in different processors in any combination.

[0060] In the above signal detection device embodiment, the specific processing details of each module are completely consistent with the above signal detection method embodiments, and will not be repeated here.

[0061] An embodiment of the present application further provides a receiver, which includes the signal detection device in the above device embodiment.

[0062] As shown in FIG6 , in an exemplary embodiment, the workflow of the receiver includes: OFDM demodulation, resource demapping, channel estimation, MIMO detection, and demodulation and decoding, wherein each embodiment of the present application relates to the MIMO detection link.

[0063] An embodiment of the present application also provides a computing device, including a processor and a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the processing steps in any one of the above method embodiments.

[0064] In particular, the computing device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0065] An embodiment of the present application further provides a computer-readable storage medium comprising computer-executable instructions. When the computer-executable instructions are executed by one or more processors, any one of the above-mentioned signal detection method embodiments is executed.

[0066] The computer-readable storage medium may include, but is not limited to, various transient or non-transient storage media that can store computer programs, such as a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk, or an optical disk.

[0067] For specific examples in this embodiment, reference may be made to the examples described in the above embodiments and exemplary implementation modes, and this embodiment will not be described in detail here.

[0068] Obviously, those skilled in the art will appreciate that the various modules or steps of the present application described above can be implemented in general or dedicated computing devices, they can be concentrated on a single computing device, or distributed on a network consisting of multiple computing devices. In one embodiment, they can be implemented using program codes executable by a computing device, so that they can be stored in a storage device and executed by the computing device. In some cases, the steps shown or described can be performed in a different order than that shown here. In other embodiments, they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. Thus, the present application is not limited to any specific combination of hardware, software, or firmware.

[0069] In order to enable those skilled in the art to better understand the technical solution of the present application, it is described below in conjunction with specific scenario embodiments.

[0070] Scenario Example 1

[0071] Assume that the transmit antenna ports of the MIMO system are numbered q (q=0, 1, ..., Q), where Q is the number of transmit antenna ports, i.e., the number of transmit ports; and the receive antenna ports are numbered p (p=0, 1, ..., P), where P is the number of receive antennas, i.e., the number of receive ports. According to the 3GPP protocol, the received signal can be expressed as:

[0072] Y=HWS+N (1)

[0073] in, Channel response matrix Precoding matrix Emission symbol noise L is the number of spatial division multiplexing layers. When the signal precoding transmission mode is single port and transmit diversity, L is 1.

[0074] In the embodiment of the present application, the prerequisite required for the MIMO system to perform signal detection processing is L≤min(P,Q), where min(.) represents the smaller value of the two.

[0075] In this scenario, the reference signal received power (RSRP) is used as a parameter to measure the power imbalance, and RSRP is used to measure the power imbalance. pq It represents the reference signal power from the transmitting port q to the receiving port p. In actual implementation, the power imbalance reference factor that can be used can also be the maximum power value of the receiving port or the transmitting port.

[0076] In this scenario embodiment, it is assumed that Q=4, P=4, and L=2, where L>1, indicating that the precoding transmission mode of the signal is the space division multiplexing mode. The received signal can be expressed as:

[0077] When performing signal detection in a receiver for MIMO detection, a minimum mean square error (MMSE) algorithm or sphere decoding (SD) detection may be used. This embodiment of the scenario adopts the MMSE detection method, and its detection formula is as follows:

[0078] in The soft decision value of signal detection for signal S is the log-likelihood ratio (LLR) output, H e =HW, the superscript “′” indicates conjugate transpose, and the superscript “-1” indicates inverse operation.

[0079] For transmit ports, Q > L and the transmitting end has port redundancy of (QL) = 2, meaning that at most two transmit ports may be deleted from subsequent processing due to insufficient power. In this scenario, deletion of a transmit port, treating the transmit signal corresponding to the transmit port as noise, or ignoring the transmit signal all indicate that the corresponding transmit port has been deleted, meaning that the port no longer participates in subsequent MIMO detection processing.

[0080] The sum of RSRP from each transmitting port q to all receiving ports is calculated as U q =(|RSRP 0q |+|RSRP 1q |+...+|RSRP Pq |) and sort them from largest to smallest. Here, assuming that U0 and U1 are relatively small values ​​among the four transmit ports, the power imbalance is calculated using the following expression:

[0081] When the following conditions are met TH is the first preset threshold. For example, if both transmitting ports 0 and 1 meet the conditions, the signals of transmitting ports 0 and 1 in formula (2) will be much smaller than the noise. Then, the channel estimation error corresponding to transmitting ports 0 and 1 will be very large, and the performance of MMSE detection processing in formula (3) will decline in the subsequent process. The corresponding transmitting ports can be deleted in the subsequent process, and formula (2) for MIMO detection processing can be simplified to:

[0082] It is equivalent to simplifying H in formula (3) e And avoid introducing a large channel estimation error to ensure signal detection performance.

[0083] Similarly, assuming that for the receiving ports, P > L and the ports have a redundancy of (P - L) = 2, that is, at most 2 receiving ports may be deleted in the subsequent process due to the received signal power being too small. The sum of the RSRP of all transmitting ports corresponding to each receiving port p is denoted as V p =(|RSRP p0 | + |RSRP p1 | +... + |RSRP pQ |), and it is sorted from large to small. Let V0 and V1 be the smaller values among the 4 receiving ports. The following expression is used to calculate the power imbalance degree:

[0084] When the following conditions are met TH is the second preset threshold. For example, if both receiving ports 0 and 1 meet this condition, the two receiving ports can be deleted in the subsequent process, and formula (2) for entering MIMO detection processing is transformed into:

[0085] It is equivalent to H in formula (3) e It is simplified and the channel estimation error is avoided to ensure signal detection performance.

[0086] Considering the number of transmitting ports and receiving ports comprehensively, as long as L < P or L < Q, there is redundancy in all ports. When the power imbalance degree of the transmitting ports exceeds the first preset threshold or the power imbalance degree of the receiving ports exceeds the second preset threshold, the signal of the corresponding channel of this port will be ignored, or in other words, this port will be deleted.

[0087] Scenario Embodiment 2

[0088] Assume that the transmitting port numbers of the multiple-input multiple-output system are q (q = 0, 1,..., Q), where Q is the number of transmitting ports; the receiving port numbers are p (p = 0, 1,..., P), where P is the number of receiving ports. According to the 3GPP protocol, the received signal is still expressed by the above formula (1):

[0089] Y = HWS + N (1)

[0090] Where channel response matrix precoding matrix transmitted symbol noise L is the number of spatial multiplexing layers. For the cases where the precoding transmission mode of the signal is single-port and transmit diversity, L is 1. The prerequisite for MIMO system detection is L ≤ min(P, Q), where min(.) represents taking the smaller value of the two.

[0091] Assume that the power imbalance of the ports is measured by the reference signal received power RSRP, and use RSRP pq as the reference signal power from transmit port q to receive port p.

[0092] In the embodiment of this scenario, assume that the precoding transmission mode of the received signal is single-port, Q = 1 and L = 1. If L < P, only when the power imbalance of the corresponding receive port exceeds the preset threshold will the receive port be deleted.

[0093] Assume that the number of receive ports is 4, P > L and the ports have a redundancy of (P - L) = 3, that is, at most 3 receive ports may be deleted in subsequent processing due to the too small received signal power. The sum of the RSRP of all transmit ports corresponding to each receive port p is denoted as V p = |RSRP p0 |, and sort them from large to small. Let V0 and V1 be the smaller values among the 4 receive ports. The power imbalance is calculated using the same expressions as formulas (6a) and (6b) above:

[0094] When TH is the second preset threshold. For example, if both receive ports 0 and 1 meet the conditions, the receive ports can be deleted in subsequent processing. Formula (2) for MIMO detection processing can be transformed into:

[0095] It is equivalent to using H in formula (3) e to obtain simplification and avoid channel estimation errors to ensure signal detection performance.

[0096] Embodiment of Scenario Three

[0097] Assume that the transmit port numbers of a multiple-input multiple-output (MIMO) system are q (q = 0, 1,..., Q), where Q is the number of transmit ports; and the receive port numbers are p (p = 0, 1,..., P), where P is the number of receive ports. According to the 3GPP protocol, the received signal is still expressed as Equation (1):

[0098] Y = HWS + N (1)

[0099] where channel response matrix precoding matrix transmitted symbol noise L is the number of spatial multiplexing layers. For the precoding transmission modes of single-port and transmit diversity of the signal, L is 1. The prerequisite for signal detection in a MIMO system is L ≤ min(P, Q), where min(.) represents taking the smaller value of the two.

[0100] Assume that the power imbalance of ports is measured by the reference signal received power (RSRP), and RSRP pq is the reference signal power from transmit port q to receive port p.

[0101] In the embodiment of this scenario, assume that the precoding transmission mode of the received signal is transmit diversity, L = 1. For the receive ports, if L < P, there is a situation where the receive ports with power imbalance exceeding the preset threshold are deleted. At this time, the signal detection process performed on the receive ports is the same as that in the case where the precoding transmission mode of the received signal in Scenario Embodiment 2 is single-port, which will not be elaborated here.

[0102] For the transmit ports, according to the 3GPP protocol, there are two cases where the number of transmit ports is 2 and 4:

[0103] When the number of transmit ports is 2, as shown in FIG3 , the two transmit ports include a first-class transmit port (transmit port 0) and a second-class transmit port (transmit port 1). When the received signal power of transmit port 0 is greater than the received signal power of transmit port 1, the power imbalance of the group of ports is calculated as the ratio of the sum of the RSRPs of transmit port 0 to the sum of the RSRPs of transmit port 1. When the calculated power imbalance is greater than a preset threshold, MRC signal detection is performed on the group of transmit ports, and the corresponding LLR results are output; when the calculated power imbalance is less than the preset threshold, the group of transmit ports is detected. The transmitting ports perform MMSE signal detection and output the corresponding LLR results. When the received signal power of transmitting port 0 is less than the received signal power of transmitting port 1, the power imbalance of the group of ports is calculated as the ratio of the sum of the RSRPs of transmitting port 1 to the sum of the RSRPs of transmitting port 0. When the calculated power imbalance is greater than the preset threshold, MRC signal detection is performed on the group of transmitting ports, the calculation results are sign-converted, and the final LLR results are output. When the calculated power imbalance is less than the preset threshold, MMSE signal detection is performed on the group of transmitting ports and the LLR results are output.

[0104] Transmitting ports 0 and 1 send s0 and s1 on the 2ith subcarrier. Transmitting ports 0 and 1 send s1 and s2 on the (2i+1)th subcarrier. The received signal is represented as (for the WIFI protocol, it refers to two adjacent symbols):

[0105] Among them, the receiving signals of the receiving port p (p=0, 1) at the 2ith and 2i+1th subcarriers are y p (2i), y p (2i+1), the channel estimation values ​​from the transmitting port q (q=0, 1) to the receiving port p (p=0, 1) at the 2ith and 2i+1th subcarriers are h respectively. pq (2i), h pq (2i+1), the noise of the receiving port p (p=0, 1) at the 2ith and 2i+1th subcarriers is n p (2i), n p (2i+1), where the superscript * indicates conjugation. The conventional method for transmitting diversity processing in a receiver is the MMSE detection method:

[0106] in represents the LLR output of signal detection on S, the superscript ' represents the conjugate transpose, and the superscript -1 represents the inverse operation.

[0107] When the transmit power of the transmit ports is unbalanced, if the received signal power of transmit port 0 is greater than the received signal power of transmit port 1, the imbalance is:

[0108] when TH is the preset threshold, and the MMSE detection of formula (10) is still used; when In formula (9), the signal at transmit port 1 is much smaller than the noise, so the channel estimation value corresponding to transmit port 1 has a large error, and the MMSE detection using formula (10) will cause performance degradation. At this time, if the channel estimation value related to transmit port 1 is set to 0, the representation of the received signal can be changed to:

[0109] That is to say, there is only one single-port transmitting signal at transmitting port 0, and the 2i-th subcarrier receiving signal can be expressed as:

[0110] The 2i+1th subcarrier received signal can be expressed as:

[0111] Then, using a simpler maximum ratio combining (MRC) and treating the signal from transmit port 1 as noise will actually improve performance. The detection method is as follows:

[0112] in They are the LLR results of signal detection for s0 and s1 respectively, and the results are output in sequence.

[0113] Similarly, if the received signal power at transmit port 0 is less than or equal to the power at transmit port 1, the imbalance is:

[0114] when TH is the preset threshold, and the MMSE detection of formula (10) is still used; when The channel estimation value corresponding to transmit port 0 can be set to 0, and the received signal can be changed to:

[0115] That is to say, it boils down to a single-port transmission signal with only transmission port 1, and the 2i-th subcarrier received signal can be expressed as:

[0116] The 2i+1th subcarrier received signal can be expressed as:

[0117] Then we first use MRC combining and regard the signal of transmit port 0 as noise. The detection method can be expressed as:

[0118] Then perform a sign change on the result:

[0119] in are the LLR outputs of signal detection for s0 and s1 respectively. The operation of formula (18a) is equivalent to The real part of is multiplied by -1 to obtain the inverse, while the imaginary part remains unchanged; the operation of formula (19b) is equivalent to The imaginary part of is multiplied by -1 to obtain the inverse, while the real part remains unchanged; in this embodiment, formula (14), formula (18) and formula (19) are collectively referred to as an improved MRC detection method.

[0120] When the number of transmit ports is 4, the ports are numbered as port 0, port 1, port 2, and port 3. Ports 0 and 2 are divided into the first group, and ports 1 and 3 are divided into the second group. The processing flow in Figure 3 is executed for each group of ports, and the LLR results of the corresponding group are output respectively.

[0121] Assume that the number of receiving ports is 2, and according to the 3GPP protocol, the transmitting ports 0 and 2 send s0 and s1 on the 4ith subcarrier. Transmitting ports 0 and 2 send s1 and s2 on the (4i+1)th subcarrier. Transmitting ports 1 and 3 send s2 and s3 on the 4i+2th subcarrier. Transmitting ports 1 and 3 send s3 and s4 on the (4i+3)th subcarrier. The received signal is represented as:

[0122] Transmit ports 0 and 2 are grouped together, and transmit ports 1 and 3 are grouped together. The processing within each group is similar to the method when the number of transmit ports is 2. The conventional method is to perform MMSE detection in formula (10).

[0123] Taking the pair of transmit ports 0 and 2 as an example, if the power of transmit port 0 is greater than the power of transmit port 2, the imbalance parameter is:

[0124] when TH is the preset threshold, and the MMSE detection of formula (10) is still used; when Using a simpler MRC combination, the signal from transmit port 2 is treated as noise. The detection method is as follows:

[0125] in These are the LLR outputs of s0 and s1 respectively.

[0126] If the received signal power of transmit port 0 is less than or equal to the received signal power of transmit port 2, the imbalance parameter is:

[0127] when TH is the preset threshold, and the MMSE detection of formula (10) is still used; when Then we first use MRC combining and treat the signal of transmit port 0 as noise, that is, the detection method is as follows:

[0128] Then perform the symbol transformation:

[0129] in are the LLR outputs of s0 and s1 respectively. The processing of transmit ports 1 and 3 can be obtained by analogy. LLR output.

[0130] The present embodiment tests the detection performance of LTE-A transmit diversity under 3GPP with imbalances of 10dB and 15dB. Referring to Figure 5 , when the imbalance is 10dB, MMSE detection outperforms the improved MRC detection method; when the imbalance is 15dB, the improved MRC detection outperforms MMSE detection. Assuming the imbalance is stepped from 10dB to 15dB in 1dB intervals, the signal-to-noise ratio (dB) required for the receiver system in this embodiment to achieve 90% throughput is statistically shown in Table 1. It can be seen that the threshold TH = 12dB is the demarcation point between the performance of MMSE detection and the improved MRC detection method.

[0131] Table 1

[0132] In summary, the present application provides a signal detection method, device, receiver, and computer-readable storage medium for a multiple-input multiple-output system. This method solves the problem that when the power imbalance between different transmitting ports and different receiving ports corresponding to the receiver reaches a certain level, the continued use of conventional receiver detection methods designed for power balance conditions will affect detection performance, thereby achieving the best possible performance while reducing processing complexity. The signal detection method primarily considers three factors: the precoding transmission mode of the signal from the transmitting port received by the receiving port, the power imbalance of the receiving port, and the power imbalance of the transmitting port; based on the above three factors, port deletion or signal ignoring processing is performed on the corresponding receiving port or transmitting port.

[0133] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A signal detection method for a multiple-input multiple-output system, comprising: Receiving signals from Q transmitting ports via P receiving ports, where both P and Q are positive integers; When L is less than or equal to the smaller value of P and Q, determining J receiving ports with relatively small received signal power among the P receiving ports or K transmitting ports with relatively small received signal power among the Q transmitting ports, where L is the spatial multiplexing layer number of the received signals, J ≤ P - L, and K ≤ Q - L; Determining the power imbalance degree of each of the J receiving ports or the power imbalance degree of each of the K transmitting ports; Performing signal detection processing on the received signals, where the signal detection processing includes signal ignoring processing, and the signal ignoring processing includes at least one of the following two: Ignoring the signals received via the receiving ports among the J receiving ports with a power imbalance degree greater than a first preset threshold; Ignoring the signals transmitted by the transmitting ports among the K transmitting ports with a power imbalance degree greater than a second preset threshold and received by the P receiving ports.

2. The signal detection method according to claim 1, where The precoding mode of the received signals is single-port, Q = 1, L = 1. When performing the signal detection processing on the received signals, the maximum ratio combining (MRC) algorithm is used, and the signal ignoring processing is: ignoring the signals received via the receiving ports among the J receiving ports with a power imbalance degree greater than a first preset threshold.

3. The signal detection method according to claim 1, where The precoding transmission mode of the received signals is spatial multiplexing, L > 1. When performing the signal detection processing on the received signals, the minimum mean square error (MMSE) algorithm or the sphere decoding (SD) algorithm is used. The signal ignoring processing includes: ignoring the signals received via the receiving ports among the J receiving ports with a power imbalance degree greater than a first preset threshold; and ignoring the signals transmitted by the transmitting ports among the K transmitting ports with a power imbalance degree greater than a second preset threshold and received by the P receiving ports.

4. The signal detection method according to claim 1, wherein, The precoding transmission mode of the received signals is transmit diversity, L = 1. The signal ignoring processing includes: ignoring the signals received via the receiving ports among the J receiving ports with a power imbalance degree greater than a first preset threshold; and ignoring the signals transmitted by the transmitting ports among the K transmitting ports with a power imbalance degree greater than a second preset threshold and received by the P receiving ports, where For the receiving ports among the J receiving ports with a power imbalance degree greater than a first preset threshold, when performing the signal detection processing on the received signals, the minimum mean square error (MMSE) algorithm or the sphere decoding (SD) algorithm is used; or For the transmitting ports among the K transmitting ports with a power imbalance degree greater than a second preset threshold, when performing the signal detection processing on the received signals, the maximum ratio combining (MRC) algorithm is used.

5. The signal detection method according to claim 1, wherein, The precoding transmission mode of the received signal is transmit diversity, L = 1. The Q transmit ports include Q / 2 first-type transmit ports and Q / 2 second-type transmit ports. The m-th first-type transmit port and the m-th second-type transmit port respectively transmit signals s on the (Q·i + 2m - 2)-th subcarrier 2m-2 and respectively transmit signals s on the (Q·i + 2m - 1)-th subcarrier 2m-1 and where the m-th first-type transmit port and the m-th second-type transmit port are regarded as the m-th group of transmit ports, m = 1, ……, Q / 2, i is a positive integer. Among them, determining the K transmit ports with relatively small received signal power among the Q transmit ports includes: For the m-th group of transmit ports, when the received signal power of the m-th first-type transmit port is greater than the received signal power of the m-th second-type transmit port, determine the m-th second-type transmit port as one of the K transmit ports; For the m-th group of transmit ports, when the received signal power of the m-th second-type transmit port is greater than the received signal power of the m-th first-type transmit port, determine the m-th first-type transmit port as one of the K transmit ports.

6. The signal detection method according to claim 5, wherein, For the m-th group of transmit ports, when the received signal power of the m-th first-type transmit port is greater than the received signal power of the m-th second-type transmit port and the power imbalance of the m-th second-type transmit port is greater than the second preset threshold, the maximum ratio combining (MRC) algorithm is adopted in the signal detection process to output For the m-th group of transmission ports, when the received signal power of the m-th second-type transmission port is greater than the received signal power of the m-th first-type transmission port and the power imbalance of the m-th first-type transmission port is greater than the second preset threshold, the maximum ratio combining (MRC) algorithm is used in the signal detection process to output The signal detection process further includes: To Perform symbol transformation processing to obtain Wherein: Among them, respectively represent the detection results of performing the signal detection processing for s 2m-2 and s 2m-1 and Indicates The real part is multiplied by -1 to be inverted, while the imaginary part remains unchanged; Indicates Multiply the imaginary part by -1 to take the inverse, while keeping the real part unchanged.

7. The signal detection method according to claim 1, wherein The precoding mode of the received signal is single port or spatial multiplexing, and The determining of the J receive ports with smaller received signal power among the P receive ports includes: Compare the received signal powers of the P receive ports, and sort the P receive ports in descending order of received signal power; Determine the last J receive ports in the sorting as the J receive ports with smaller received signal power among the P receive ports; The determining of the K transmit ports with smaller received signal power among the Q transmit ports includes: Compare the received signal powers of the Q transmit ports, and sort the Q transmit ports in descending order of received signal power; Determine the last K transmit ports in the sorting as the K transmit ports with smaller received signal power among the Q transmit ports. The precoding mode of the received signal is transmit diversity, and 8. The signal detection method according to claim 1, wherein The determining of the J receive ports with smaller received signal power among the P receive ports includes: Compare the received signal powers of the P receive ports, and sort the P receive ports in descending order of received signal power; Determine the last J receive ports in the sorting as the J receive ports with smaller received signal power among the P receive ports. Determine the received signal powers of the P receive ports and the Q transmit ports in the following manner:

9. The signal detection method according to any one of claims 1 to 8, wherein For each receive port among the P receive ports, calculate the sum of the powers of the signals received by this receive port from the Q transmit ports as the received signal power of this receive port; For each transmit port among the Q transmit ports, calculate the sum of the powers of the signals received by the P receive ports that are transmitted by this transmit port as the received signal power of this transmit port.

10. The signal detection method according to any one of claims 1 to 9, wherein, Determining the power imbalance degree of each receive port among the J receive ports includes: Select all or part of the receive ports other than the J receive ports among the P receive ports as comparison receive ports; For each receive port among the J receive ports, calculate the ratio of the received signal power of this receive port to the received signal power of each comparison receive port among the comparison receive ports, and take the smallest ratio as the power imbalance degree of this receive port; Determining the power imbalance degree of each transmit port among the K transmit ports includes: ​ Select all or part of the transmit ports from the transmit ports other than the K transmit ports among the Q transmit ports as comparison transmit ports; For each of the K transmit ports, calculate the ratio of the received signal power of this transmit port to the received signal power of each comparison transmit port among the comparison transmit ports, and take the smallest ratio as the power imbalance of this transmit port.

11. The signal detection method according to claim 10, wherein, When the precoding transmission mode of the received signal is single-port or spatial division multiplexing, The selection of all or part of the receive ports from the receive ports other than the J receive ports among the P receive ports as comparison receive ports includes: Select all the receive ports from the receive ports other than the J receive ports among the P receive ports as comparison receive ports; The selection of all or part of the transmit ports from the transmit ports other than the K transmit ports among the Q transmit ports as comparison transmit ports includes: Select all the transmit ports from the transmit ports other than the K transmit ports among the Q transmit ports as comparison transmit ports.

12. The signal detection method according to claim 10, wherein, When the precoding transmission mode of the received signal is transmit diversity: The selection of all or part of the receive ports from the receive ports other than the J receive ports among the P receive ports as comparison receive ports includes: Select all the receive ports from the receive ports other than the J receive ports among the P receive ports as comparison receive ports.

13. The signal detection method according to claim 5, wherein, Determining the power imbalance of each of the K transmit ports includes: When the m-th second type of transmit port is determined to be one of the K transmit ports, calculate the ratio of the received signal power of the m-th first type of transmit port to the received signal power of the m-th second type of transmit port, as the power imbalance of the transmit port corresponding to the m-th group among the K transmit ports; When the m-th first type of transmit port is determined to be one of the K transmit ports, calculate the ratio of the received signal power of the m-th second type of transmit port to the received signal power of the m-th first type of transmit port, as the power imbalance of the transmit port corresponding to the m-th group among the K transmit ports, where m = 1,..., Q / 2.

14. The signal detection method according to claim 5, wherein When the precoding transmission mode of the received signal is transmit diversity, the value of Q is 2 or 4.

15. The signal detection method according to claim 4, wherein, For the receive ports among the J receive ports with a power imbalance less than or equal to the first preset threshold or the transmit ports among the K transmit ports with a power imbalance less than or equal to the second preset threshold, when performing the signal detection processing on the received signal, use the minimum mean square error MMSE algorithm or the sphere decoding SD algorithm.

16. A signal detection device for a multiple-input multiple-output system, in which signals from Q transmitting ports are received via P receiving ports in the multiple-input multiple-output system, where, Both P and Q are positive integers, wherein the signal detection device includes: A power comparison module configured to determine J receive ports with relatively small received signal power among P receive ports or K transmit ports with relatively small received signal power among Q transmit ports, where L is the number of spatial division multiplexing layers of the received signal, J ≤ P - L, K ≤ Q - L; An imbalance calculation module configured to determine the power imbalance of each of the J receiving ports or the power imbalance of each of the K transmitting ports; A signal detection and processing module configured to perform signal detection and processing on the received signals, wherein the signal detection and processing of the received signals includes signal ignoring processing, and the signal ignoring processing includes at least one of the following two: Ignoring the signals received via the receiving ports among the J receiving ports with a power imbalance greater than a first preset threshold; Ignoring the signals transmitted by the transmitting ports among the K transmitting ports with a power imbalance greater than a second preset threshold and received by the P receiving ports.

17. A receiver, the receiver comprising the signal detection device as claimed in claim 16.

18. A computing device, comprising a processor and a memory, and a computer program stored on the memory and executable on the processor, wherein when the processor executes the computer program, the signal detection method described in any one of claims 1 to 15 is implemented.

19. A computer-readable storage medium, comprising computer-executable instructions, which when run by one or more processors, execute the signal detection method described in any one of claims 1 - 15.

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