Pilot allocation method and device for 5G MIMO system

Abstract

This application discloses a pilot allocation method and apparatus for a 5G MIMO system. The pilot allocation method for a 5G MIMO system includes: a base station obtaining terminal location information and the signal-to-noise ratio of the terminal's pilot; and the base station allocating pilots to each terminal within a cell based on the terminal's location information and the signal-to-noise ratio. This application enhances the flexibility of pilot allocation, improves the accuracy of pilot channel estimation, and improves system capacity.

Description

Technical Field

[0001] The present application relates to the field of mobile communication technology, and in particular to a pilot allocation method and device for a 5G MIMO system. Background Art

[0002] Massive MIMO (Multiple-Input Multiple-Output) technology, a key technology for fifth-generation mobile communication systems (5G), fully utilizes spatial dimensions, effectively increases data transmission rates, and reduces power consumption. In practical wireless communication systems, to accurately and promptly obtain channel information, base stations typically estimate the channel based on pilot signals from terminals.

[0003] Due to system complexity, massive MIMO technology is primarily used in TDD (Time Division Duplex) systems. In TDD multi-cell massive 5G MIMO systems, due to the short channel coherence time and the limited number of orthogonal pilots, it is impossible to assign orthogonal pilots to all terminals. This inevitably leads to pilot reuse among users in all cells. This inevitably causes pilot contamination, resulting in inaccurate channel estimation for terminals by the base station, and is a major factor in reducing the channel capacity of the communication system. Therefore, how to mitigate pilot contamination in massive 5G MIMO systems has become a focus of intense research in the communications field.

[0004] The preceding description is intended to provide general background information and does not necessarily constitute prior art. Summary of the Invention

[0005] The purpose of this application is to provide a pilot allocation method and device for a 5G MIMO system, which can enhance the flexibility of pilot allocation and improve the accuracy of pilot channel estimation and system capacity.

[0006] To achieve the above objectives, the technical solution of this application is implemented as follows:

[0007] In a first aspect, an embodiment of the present application provides a pilot allocation method for a 5G MIMO system, including: a base station obtains terminal location information and a signal-to-noise ratio of a terminal pilot, and the base station allocates a pilot to each terminal in a cell based on the terminal location information and the signal-to-noise ratio.

[0008] As one of the implementation methods, the steps are further included: measuring the pilot allocated by the base station through the terminal, calculating the terminal's location information and the signal-to-noise ratio of the pilot received by the terminal, and reporting the location information and the signal-to-noise ratio of the pilot to the base station through the terminal.

[0009] In one implementation manner, measuring a pilot signal allocated by a base station by a terminal to calculate the terminal's location information and a signal-to-noise ratio of the pilot signal received by the terminal includes:

[0010] The terminal automatically measures the downlink pilot signal allocated by the base station, and continuously calculates the terminal's location information and the signal-to-noise ratio of the pilot signal received by the terminal based on the information of the downlink pilot signal.

[0011] As one implementation manner, the information of the downlink pilot signal includes TDOA, AOA or signal strength information.

[0012] As one implementation manner, the terminal operates in a cellular network in which each base station adopts a multi-point coordinated technology, and each cell in the cellular network maintains strict time and frequency synchronization.

[0013] In one implementation manner, the base station allocates a pilot signal to each terminal in a cell according to the location information and signal-to-noise ratio of the terminal, including:

[0014] The base station allocates a pilot in the orthogonal pilot sequence to all terminals located at the center of the cell covered by the base station; the remaining pilots are preferentially allocated to the first type of edge terminals, and the remaining pilots after the allocation to the first type of edge terminals are allocated to the second type of edge terminals. The terminals are divided into central terminals, first type of edge terminals, and second type of edge terminals based on their location information and signal-to-noise ratio.

[0015] As one implementation method, the method further includes the following steps: if there are not enough pilots to allocate, all the terminals with high signal-to-noise ratios among the second type of edge terminals use the last pilot.

[0016] As one embodiment, the method further includes the steps of:

[0017] The base station continuously acquires the pilot signal of each terminal at a certain time interval to obtain the precoding matrix of each terminal at different time points;

[0018] The base station calculates the similarity of the precoding matrix of each terminal at different time points, and determines whether the similarity of the precoding matrix at different time points is greater than a similarity threshold;

[0019] If it is greater than the similarity threshold, it is determined that the terminal is moving at high speed. The base station reallocates the pilots, allocates the same pilots to the terminals at the center of the cell, allocates the remaining orthogonal pilots to the terminals moving at high speed first, and then allocates the other orthogonal pilots to the terminals at the edge of the cell.

[0020] As one of the implementation methods, the terminal further includes the steps of: the terminal calculates the speed of the terminal through its own acceleration sensor, gyroscope, or geomagnetic sensor, and reports it to the base station; if the similarity of the precoding matrix is greater than the similarity threshold and the speed of the terminal is greater than the speed threshold, it is determined that the terminal is moving at high speed.

[0021] In one implementation, the base station reallocates pilots, allocating the same pilots to terminals at the center of the cell, prioritizing the remaining orthogonal pilots to terminals moving at high speeds, and then allocating the remaining orthogonal pilots to terminals at the edge of the cell, including:

[0022] The base station fixedly allocates the first pilot N1 in the orthogonal pilot sequence to the terminal at the cell center, and randomly allocates the pilots N2...Nm in the pilot sequence to high-speed mobile terminals. After allocating the high-speed mobile terminals, the remaining pilots in the pilot sequence N2...Nm are preferentially allocated to the first type of edge terminals. After allocating the first type of edge terminals, the remaining pilots are allocated to the second type of edge terminals, where N1...Nm are orthogonal pilot sequences and m is an integer greater than 1.

[0023] In a second aspect, an embodiment of the present application provides a pilot allocation method for a 5G MIMO system, including: a terminal measures a pilot allocated by a base station, calculates the position information of the terminal and the signal-to-noise ratio of the pilot received by the terminal, and the terminal reports the position information and the signal-to-noise ratio of the pilot to the base station; the base station obtains the position information of the terminal and the signal-to-noise ratio of the terminal pilot; the base station allocates a pilot to each terminal in the cell based on the position information and the signal-to-noise ratio of the terminal.

[0024] In a third aspect, an embodiment of the present application provides a pilot allocation apparatus for a 5G MIMO system, comprising a memory and a processor. The processor is configured to execute a computer program stored in the memory to implement the steps of the pilot allocation method for the 5G MIMO system described above.

[0025] The beneficial effects of the technical solution provided by the embodiments of the present application are:

[0026] The pilot allocation method and apparatus for a 5G MIMO system provided in an embodiment of the present application obtains terminal location information and the signal-to-noise ratio of the terminal's pilot signal through a base station. The base station then allocates pilot signals to terminals within a cell based on the terminal's location information and signal-to-noise ratio. Thus, the pilot allocation method for a 5G MIMO system provided in an embodiment of the present application can obtain accurate terminal location information and signal-to-noise ratio, and can also flexibly allocate pilot signals to terminals based on the terminal's location information and signal-to-noise ratio, thereby improving the accuracy of pilot channel estimation and system capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flowchart of a pilot allocation method for a 5G MIMO system provided in an embodiment of the present application;

[0028] Figure 2 Schematic diagram of a basic network model of a multi-cell 5G MIMO system according to an embodiment of the present application;

[0029] Figure 3 A flowchart of a pilot allocation method for a 5G MIMO system provided in another embodiment of the present application;

[0030] Figure 4 A block diagram of a pilot allocation system for a 5G MIMO system provided in an embodiment of the present application;

[0031] Figure 5 A block diagram of a pilot allocation device for a 5G MIMO system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The technical solution of this application is further described in detail below with reference to the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0033] Figure 1 A flowchart of a pilot allocation method for a 5G MIMO system provided in an embodiment of the present application is provided. Figure 2 This is a basic network model diagram of a multi-cell 5G MIMO system according to an embodiment of the present application. Figure 1 and Figure 2 The pilot allocation method is applied to a pilot allocation device. The pilot allocation device can be implemented in software and / or hardware. In a specific application, the pilot allocation device can be a base station. In this embodiment, the pilot allocation method is applied to a base station as an example. The pilot allocation method includes the following steps:

[0034] Step S102: The base station obtains the location information of the terminal and the signal-to-noise ratio of the terminal pilot;

[0035] Preferably, before step S102, the step may further include: measuring the pilot allocated by the base station by the terminal, calculating the terminal's location information and the signal-to-noise ratio of the pilot received by the terminal, and reporting the location information and the signal-to-noise ratio of the pilot to the base station by the terminal.

[0036] Specifically, terminals B1, B2, B3, C1, C2, and C3 can automatically measure the downlink pilots assigned by the base station, and continuously calculate the terminal's location information and signal-to-noise ratio based on the downlink pilot signal information, such as TDOA, AOA, or signal strength. The terminal then reports the location information and signal-to-noise ratio to base stations M1, M2, and M3. Here, each terminal in each cell reports its location information and signal-to-noise ratio to the base station in that cell. For example, terminals B1 and C1 in cell 20 report their location information and signal-to-noise ratio to base station M1 in cell 20, terminals B2 and C2 in cell 21 report their location information and signal-to-noise ratio to base station M2 in cell 21, and terminals B3 and C3 in cell 22 report their location information and signal-to-noise ratio to base station M3 in cell 22. The downlink pilots assigned by the base stations automatically measured by the terminals are the pilots assigned by the base stations in the cells where the terminals are located.

[0037] Here, the terminal works in a cellular network where each base station adopts Coordinated Multi-Point (CoMP) technology, and each cell in the cellular network maintains strict time and frequency synchronization. Figure 2 As shown in the figure, in the actual operation process, each terminal B1, B2, B3, C1, C2, C3 can be uniformly numbered as Hi, j, k, where i takes the value of 0 or 1, "1" means the terminal is in high-speed movement, "0" means the terminal is not in high-speed movement; "j" is the cell number, which is usually between 0 and 6; "k" is the terminal number, that is, the terminal number of a certain cell. Here, each base station gives the cell it covers (such as Figure 2 As shown in the figure, the pilot allocation method for each area covered by the cellular network is the same. The pilot allocation method of the present application is applicable to any base station. The terminal's location information and signal-to-noise ratio are used to determine whether the terminal is in the cell center or the cell edge. For example, if the distance between the terminal and the base station is less than or equal to a preset distance, such as 800 meters, the terminal is in the cell center and is a central terminal. A terminal with a distance from the cell center greater than a preset distance, such as 800 meters, and a signal-to-noise ratio less than a preset value, such as 5 dB, belongs to the first category of edge terminals, and other terminals belong to the second category of edge terminals.

[0038] Step S103: The base station allocates pilot signals to each terminal in the cell according to the location information and signal-to-noise ratio of the terminal.

[0039] Specifically, step S103 may include:

[0040] The base station assigns one pilot in the orthogonal pilot sequence to all terminals located at the center of the cell covered by the base station. The remaining pilots are preferentially assigned to the first type of edge terminals, and the other pilots after the first type of edge terminals are assigned to the second type of edge terminals. As described above, the terminals are divided into central terminals, the first type of edge terminals, and the second type of edge terminals according to the location information and signal-to-noise ratio. That is, the pilots used by the terminals at the cell center are the same, and the remaining orthogonal pilots are assigned to the edge terminals at the cell edge according to the first and second types of edge terminals. Taking cell 20 as an example, base station M1 assigns one pilot in the orthogonal pilot sequence to all terminals C1 located at the center of cell 20 covered by base station M1 (here only one terminal at the cell center is used as an example for illustration. In practice, there can be multiple terminals at the cell center), and then assigns the remaining pilots to the first type of edge terminals B1 of the cell (here only one terminal of the first type of edge terminals of the cell is used as an example for illustration. In practice, there can be multiple). The other pilots after the first type of edge terminals are assigned to the second type of edge terminals. If the pilots are not enough for distribution, the terminals with high signal-to-noise ratio among the second type of edge terminals all use the last pilot. That is to say, for the orthogonal pilot sequences N1,..., Nm, where m is an integer satisfying 1 < m < j × k, the base station can fixedly assign the first pilot N1 in the orthogonal pilot sequence to all terminals located at the cell center. For the remaining pilots except the first pilot, they are preferentially assigned to the first type of edge terminals, and the other pilots are assigned to the second type of edge terminals. If the pilots are not enough for distribution, the terminals with high signal-to-noise ratio all use the pilot Nm. If there are remaining pilots after the distribution, they are retained. The terminals with high signal-to-noise ratio are the terminals whose signal-to-noise ratio is higher than a preset value.

[0041] It should be noted that to determine whether a terminal is located at the cell center or at the cell edge, it is judged according to the terminal location and the sum signal-to-noise ratio of the pilot signal. For example, if the distance between the terminal and the base station is less than or equal to a preset distance, for example, the preset distance is 800 meters, then it is judged that the terminal is located at the cell center and is a central terminal. If the distance from the cell center is greater than the preset distance, for example, 800 meters and the signal-to-noise ratio is less than the preset value, for example, 5 dB, it belongs to the first type of edge terminals, and other terminals belong to the second type of edge terminals. The first type of edge terminals and the second type of edge terminals both belong to edge terminals.

[0042] Under normal circumstances, the pilot pollution caused by the terminal in the center of each cell is relatively small, and the pilot pollution caused by the terminal at the edge of each cell is relatively large, so accurate terminal position measurement is the key. Because the terminal of this application works in a network that adopts multi-point coordinated technology (CoMP, Coordinated Multi-Point), due to the use of multi-point coordinated technology, each cell will ensure strict time and frequency synchronization, so that the terminal can use TDOA (Time Difference of Arrive, arrival time difference), AoA (Angle of Arrive, arrival angle), signal strength and other information to obtain accurate terminal location information, avoiding the problem of large errors in estimating terminal position using only signal strength, signal-to-noise ratio or large-scale fading information and the inability of GPS to locate indoors or near high-rise buildings.

[0043] Preferably, steps S104-S107 may also be included.

[0044] Step S104: The base station continuously measures the pilot signal of each terminal at a certain time interval to obtain the precoding matrix of each terminal at different time points.

[0045] Specifically, the base station obtains pilot signals from each terminal at regular intervals, for example, every 2 seconds, and calculates the precoding matrix Aj,k,tn for each terminal based on the obtained pilot signals, where "tn" represents a different time point. The precoding matrix can be calculated using existing precoding matrix calculation methods.

[0046] In step S105, the base station calculates the similarity of the precoding matrices of each terminal at different time points, and determines whether the similarity of the precoding matrices at different time points is greater than a threshold. If the matrix similarity is greater than the similarity threshold and the terminal speed is greater than the speed threshold, step S106 is performed; if not, step S106 is performed.

[0047] Specifically, step S105 may also include: the terminal may also simultaneously activate its own acceleration sensor, gyroscope, or geomagnetic sensor to calculate the terminal's speed at the aforementioned different time points, and report the speed to the base station. The base station calculates the similarity of the precoding matrices of each terminal at different time points and the obtained terminal speed. If the similarity of the precoding matrices exceeds a similarity threshold and the terminal's speed exceeds a speed threshold, the terminal is determined to be in high-speed motion and the terminal's identifier "i" is set to "1," indicating that the terminal is in high-speed motion. Because the terminal's position is time-varying and difficult to accurately measure during high-speed motion, this must also be considered when allocating pilot signals. This application addresses the issue of the difficulty in accurately measuring the terminal's position during high-speed motion, thereby significantly improving the network's overall communication capacity. Furthermore, the concept of matrix similarity is introduced. Within a certain time interval, the base station compares the obtained similarity of the terminal's precoding matrix with the terminal's speed to determine whether the terminal is in high-speed motion. Orthogonal pilot signals are consistently allocated to these terminals, reducing system overhead and thereby maximizing the network's overall communication capacity. The similarity calculation method can utilize existing matrix similarity calculation methods. The above thresholds can be set in advance.

[0048] In step S106, it is determined that the terminal is moving at high speed, and the base station reallocates the pilots. The terminals at the center of the cell are still allocated the same pilots, and the remaining orthogonal pilots are preferentially allocated to the terminals moving at high speed. Then, the other orthogonal pilots are allocated to the terminals at the edge of the cell, that is, they can be allocated according to the methods of the first and second types of edge terminals mentioned above.

[0049] Specifically, when it is determined that the terminal is moving at high speed, the base station reallocates the pilots. The first pilot N1 is still allocated to the terminal at the center of the cell, and the remaining orthogonal pilots are preferentially allocated to the terminal with "i" being "1", and the others are allocated to the terminals at the edge of the cell.

[0050] Here, in step S106, the terminals at the cell center are allocated the same pilots, the remaining orthogonal pilots are preferentially allocated to high-speed mobile terminals, and the remaining orthogonal pilots are then allocated to the terminals at the cell edge. Specifically, this may include: the base station fixedly allocates the first pilot N1 in the orthogonal pilot sequence to the terminals at the cell center, and preferentially and randomly allocates the pilots N2...Nm in the pilot sequence to the high-speed mobile terminals. After allocating the pilots to the high-speed mobile terminals, the remaining pilots in the pilot sequence N2...Nm are preferentially allocated to the first type of edge terminals. After allocating the pilots to the first type of edge terminals, the remaining pilots are allocated to the second type of edge terminals. For example, during allocation, the remaining pilots may be allocated to the terminals at the cell edge in ascending order of terminal signal-to-noise ratio. Preferably, if insufficient pilots are allocated, the second type of edge terminals with high signal-to-noise ratios all use pilot Nm. Where N1...Nm are orthogonal pilot sequences, and m is an integer greater than 1.

[0051] Step S107: Keep the last allocated pilot unchanged and proceed to step S104.

[0052] Here, steps S104-S107 are repeated. In this way, the base station can continuously monitor the status of the terminals and dynamically allocate pilots to each terminal according to the priority order of high-speed mobile > cell edge > cell center. Specifically, the base station determines whether any terminals in the cell are in high-speed mobile mode. If so, the pilots are reallocated: the pilots for terminals in the cell center remain unchanged, and the remaining pilots are allocated in the order of high-speed mobile terminals, first-category edge terminals, and second-category edge terminals. For example, the base station can permanently allocate the first pilot N1 to the central terminal and randomly allocate pilots N2...Nm in the pilot sequence to high-speed mobile terminals. After allocating pilots to high-speed mobile terminals, the remaining pilots in the pilot sequence N2...Nm are randomly or sequentially allocated to first-category edge terminals according to the order of the pilot sequence, and the remaining pilots are allocated to second-category cell edge terminals. For example, the remaining pilots can be allocated to cell edge terminals in ascending order of terminal signal-to-noise ratio.

[0053] In summary, the pilot allocation method for a 5G MIMO system provided in an embodiment of the present application obtains terminal location information and the signal-to-noise ratio of the terminal pilot through a base station. The base station then allocates pilots to each terminal in the cell based on the terminal location information and signal-to-noise ratio. Thus, the pilot allocation method for a 5G MIMO system provided in an embodiment of the present application can obtain accurate terminal location information and signal-to-noise ratio, and can also flexibly allocate pilots to terminals based on the terminal location information and signal-to-noise ratio, thereby improving the accuracy of pilot channel estimation and system capacity.

[0054] In addition, because the terminal operates in a network that uses Coordinated Multi-Point (CoMP) technology, each cell ensures strict time and frequency synchronization. This allows the terminal to use information such as TDOA (Time Difference of Arrive), AoA (Angle of Arrive), and signal strength to obtain accurate terminal location information and signal-to-noise ratio (SNR). This avoids the large errors in estimating terminal location using only signal strength, SNR, or large-scale fading information, as well as the problem of GPS being unable to locate indoors or near tall buildings.

[0055] In addition, the problem of inability to accurately measure the position of a terminal when it moves at high speed is taken into consideration. Matrix similarity and the terminal's own inertial elements are introduced to measure speed. Within a certain time interval, the base station compares the similarity and speed of the obtained precoding matrix of the terminal to determine whether the terminal is moving at high speed. Orthogonal pilots are always allocated to these high-speed mobile terminals to reduce system overhead and thus maximize the overall communication capacity of the network.

[0056] Figure 3 : This is a flow chart of a pilot allocation method for a 5G MIMO system provided by another embodiment of the present application. The pilot allocation method is applied to a pilot allocation system, which can be implemented in software and / or hardware. In a specific application, the pilot allocation system can be a system composed of a terminal and a base station. In this embodiment, the pilot allocation method is applied to a system composed of a terminal and a base station as an example. Figure 1 The method shown is similar except that Figure 3 Before step S102, the following step may be included: step S301.

[0057] In step 301, the terminal measures the pilot signal allocated by the base station, calculates the terminal's location information and the signal-to-noise ratio of the pilot signal received by the terminal, and reports the location information and the signal-to-noise ratio of the pilot signal to the base station.

[0058] Specifically, terminals B1, B2, B3, C1, C2, and C3 can automatically measure the downlink pilots assigned by the base station, and continuously calculate the terminal's location information and signal-to-noise ratio based on the downlink pilot signal information, such as TDOA, AOA, or signal strength. The terminal then reports the location information and signal-to-noise ratio to base stations M1, M2, and M3. Here, each terminal in each cell reports its location information and signal-to-noise ratio to the base station in that cell. For example, terminals B1 and C1 in cell 20 report their location information and signal-to-noise ratio to base station M1 in cell 20, terminals B2 and C2 in cell 21 report their location information and signal-to-noise ratio to base station M2 in cell 21, and terminals B3 and C3 in cell 22 report their location information and signal-to-noise ratio to base station M3 in cell 22. The downlink pilots assigned by the base stations automatically measured by the terminals are the pilots assigned by the base stations in the cells where the terminals are located.

[0059] Figure 4 This is a block diagram of the pilot allocation system of the 5G MIMO system provided by the embodiment of the present application. In order to clearly describe the pilot allocation system of the 5G MIMO system provided by the embodiment of the present application, please refer to Figure 4 .

[0060] The pilot allocation system of the 5G MIMO system provided in the embodiment of the present application includes a position information calculation module 30 and a first pilot allocation module 31.

[0061] The location information calculation module 30 is configured to measure the pilot signal allocated by the base station through the terminal, calculate the location information of the terminal and the signal-to-noise ratio of the pilot signal received by the terminal, and report the location information and the signal-to-noise ratio of the pilot signal to the base station through the terminal;

[0062] The first pilot allocation module 31 is configured to obtain the terminal's location information and the signal-to-noise ratio of the terminal's pilot, and allocate the pilot to each terminal in the cell according to the terminal's location information and the signal-to-noise ratio.

[0063] In one embodiment, the location information calculation module 30 is further configured to automatically measure the downlink pilot allocated by the base station through the terminal, and continuously calculate the location information of the terminal and the signal-to-noise ratio of the pilot received by the terminal based on the information of the downlink pilot signal.

[0064] In one embodiment, the information of the downlink pilot signal includes TDOA, AOA or signal strength information.

[0065] In one embodiment, the terminal operates in a cellular network in which each base station adopts a coordinated multi-point technology, and each cell in the cellular network maintains strict time and frequency synchronization.

[0066] In one embodiment, the first pilot allocation module 31 is further configured to allocate a pilot in the orthogonal pilot sequence to all terminals located at the center of the cell covered by the base station, and preferentially allocate the remaining pilots to the first type of edge terminals. After the pilots are allocated to the first type of edge terminals, the remaining pilots are allocated to the second type of edge terminals. The terminals are divided into central terminals, first type of edge terminals, and second type of edge terminals according to their location information and signal-to-noise ratio. Preferably, if there are insufficient pilots to allocate, the terminals with a high signal-to-noise ratio among the second type of edge terminals all use the last pilot.

[0067] In one embodiment, the system may further include: a precoding matrix and terminal speed acquisition module 32 , a similarity determination module 33 , and a second pilot allocation module 34 .

[0068] The precoding matrix and terminal speed acquisition module 32 is used to continuously measure the pilot signal of each terminal at a certain time interval to obtain the precoding matrix and terminal speed of each terminal at different time points;

[0069] The similarity determination module 33 is used to calculate the similarity of the precoding matrix of each terminal at different time points, and determine whether the similarity of the precoding matrix at different time points is greater than a similarity threshold and whether the terminal speed is greater than a speed threshold;

[0070] The second pilot allocation module 34 is used to determine that the terminal is in high-speed movement if it is greater than the threshold, and reallocate the pilots. The terminals in the center of the cell are allocated the same pilots, and the remaining orthogonal pilots are preferentially allocated to the high-speed moving terminals. Then, the other orthogonal pilots are allocated to the terminals at the edge of the cell. That is, the remaining pilots are allocated according to the first and second types of edge terminal pilot allocation methods mentioned above.

[0071] In one embodiment, the second pilot allocation module 34 is further configured to fixedly allocate the first pilot N1 in the orthogonal pilot sequence to the terminal at the cell center, randomly allocate pilots N2...Nm in the pilot sequence preferentially to high-speed mobile terminals, and after allocating pilots to the high-speed mobile terminals, preferentially allocate the remaining pilots in the pilot sequence N2...Nm to the first type of edge terminals. After allocating pilots to the first type of edge terminals, the remaining pilots are allocated to the second type of edge terminals. Where N1...Nm are orthogonal pilot sequences, and m is an integer greater than 1. Preferably, if there are insufficient pilots to allocate, the second type of edge terminals with a high signal-to-noise ratio all use pilot Nm.

[0072] In one embodiment, the specific implementation and beneficial effects of the pilot allocation system of the 5G MIMO system provided in this embodiment can refer to the pilot allocation method of the 5G MIMO system provided in the embodiment of the present application, and will not be repeated here.

[0073] In summary, the pilot allocation system for a 5G MIMO system provided in an embodiment of the present application obtains terminal location information through a base station, and the base station allocates pilots to terminals within a cell based on the terminal location information. Thus, the pilot allocation method for a 5G MIMO system provided in an embodiment of the present application can obtain accurate terminal location information and signal-to-noise ratio, and can also flexibly allocate pilots to terminals based on terminal location information and signal-to-noise ratio, thereby improving the accuracy of pilot channel estimation and system capacity.

[0074] Figure 5 This is a block diagram of a pilot allocation device for a 5G MIMO system according to an embodiment of the present application. Figure 5 .

[0075] like Figure 5 As shown, the pilot allocation device of the 5G MIMO system includes: a processor 110 and a memory 111 for storing a computer program that can be run on the processor 110; wherein, Figure 5 The processor 110 shown in the figure is not used to indicate that the number of processors 110 is one, but is only used to indicate the positional relationship of the processor 110 relative to other devices. In actual applications, the number of processors 110 may be one or more; similarly, Figure 5The memory 111 shown in the figure has the same meaning, that is, it is only used to refer to the position relationship of the memory 111 relative to other devices. In actual applications, the number of memories 111 can be one or more. Among them, the processor 110 is used to implement the pilot allocation device method of the 5G MIMO system when running the computer program.

[0076] The pilot allocation device of the 5G MIMO system may further include: at least one network interface 112. The various components in the pilot allocation device of the 5G MIMO system are coupled together via a bus system 113. It is understood that the bus system 113 is used to achieve connection and communication between these components. In addition to the data bus, the bus system 113 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, Figure 5 Various buses are labeled as bus system 113 .

[0077] The memory 111 may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. The non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a ferromagnetic random access memory (FRAM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM); the magnetic surface memory may be a magnetic disk or a magnetic tape. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), synchronous static random access memory (SSRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus random access memory (DRRAM).The memory 111 described in the embodiments of the present application is intended to include but is not limited to these and any other suitable types of memories.

[0078] The memory 111 in the embodiment of the present application is used to store various types of data to support the operation of the pilot allocation device of the 5G MIMO system. Examples of these data include: any computer program for operating on the pilot allocation device of the 5G MIMO system, such as an operating system and an application; contact data; phone book data; messages; pictures; videos, etc. Among them, the operating system includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., which are used to implement various basic services and process hardware-based tasks. The application program may include various applications, such as a media player (MediaPlayer), a browser (Browser), etc., for implementing various application services. Here, the program that implements the method of the embodiment of the present application may be included in the application.

[0079] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] It should be noted that, in this document, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, components, features, and elements with the same name in different embodiments of the present application may have the same meaning or different meanings, and their specific meanings need to be determined by their explanation in the specific embodiment or further combined with the context of the specific embodiment.

[0081] It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are merely used to distinguish information of the same type from one another. For example, without departing from the scope of this document, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the term "if" as used herein may be interpreted as "at the time of," "when," or "in response to a determination." Furthermore, as used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It should be further understood that the terms "comprising" and "including" indicate the presence of the described features, steps, operations, elements, components, items, types, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, types, and / or groups. The terms "or" and "and / or" as used herein are to be interpreted as inclusive, meaning any one or any combination. Thus, “A, B, or C” or “A, B, and / or C” means “any of: A; B; C; A and B; A and C; B and C; A, B, and C.” An exception to this definition occurs only when a combination of elements, functions, steps, or operations are inherently mutually exclusive in some manner.

[0082] It should be understood that, although the various steps in the flowchart in the embodiment of the present application are shown in sequence according to the indication of the arrows, these steps are not necessarily performed in sequence in the order indicated by the arrows. Unless clearly stated herein, the execution of these steps is not strictly limited in order, and they can be performed in other orders. Moreover, at least a portion of the steps in the figure may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and their execution order is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of other steps or sub-steps or stages of other steps.

[0083] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A pilot allocation method for a 5G MIMO system, characterized in that: include: The base station obtains the terminal's location information and the signal-to-noise ratio of the terminal's pilot signal; The base station allocates pilot signals to each terminal in the cell according to the terminal's location information and signal-to-noise ratio; The base station continuously acquires the pilot signal of each terminal at a certain time interval to obtain the precoding matrix of each terminal at different time points; The base station calculates the similarity of the precoding matrix of each terminal at different time points, and determines whether the similarity of the precoding matrix at different time points is greater than a similarity threshold; If it is greater than the similarity threshold, it is determined that the terminal is moving at high speed. The base station reallocates the pilots, allocates the same pilots to the terminals at the center of the cell, allocates the remaining orthogonal pilots to the terminals moving at high speed first, and then allocates the other orthogonal pilots to the terminals at the edge of the cell.

2. The method according to claim 1, wherein The method further includes the steps of measuring the pilot allocated by the base station through the terminal, calculating the terminal's position information and the signal-to-noise ratio of the pilot received by the terminal, and reporting the position information and the signal-to-noise ratio of the pilot to the base station through the terminal.

3. The method according to claim 2, wherein The terminal measures the pilot signal assigned by the base station and calculates the terminal's location information and the signal-to-noise ratio of the pilot signal received by the terminal, including: The terminal automatically measures the downlink pilot signal allocated by the base station, and continuously calculates the terminal's location information and the signal-to-noise ratio of the pilot signal received by the terminal based on the information of the downlink pilot signal.

4. The method according to claim 3, wherein The information of the downlink pilot signal includes TDOA, AOA or signal strength information.

5. The method according to claim 2, wherein The terminal operates in a cellular network in which each base station adopts a multi-point coordinated technology, and each cell in the cellular network maintains strict time and frequency synchronization.

6. The method according to claim 1, wherein The base station allocates pilot signals to each terminal in the cell according to the terminal's location information and signal-to-noise ratio, including: The base station allocates a pilot in the orthogonal pilot sequence to all terminals located at the center of the cell covered by the base station; the remaining pilots are preferentially allocated to the first type of edge terminals, and the remaining pilots after the allocation to the first type of edge terminals are allocated to the second type of edge terminals. The terminals are divided into central terminals, first type of edge terminals, and second type of edge terminals based on their location information and signal-to-noise ratio.

7. The method of claim 6, further comprising the steps of: If there are not enough pilots to allocate, the terminals with high signal-to-noise ratio in the second type of edge terminals all use the last pilot.

8. The method according to claim 1, wherein The method further includes the following steps: the terminal calculates the speed of the terminal through its own acceleration sensor, gyroscope, or geomagnetic sensor and reports it to the base station; if the similarity of the precoding matrix is greater than the similarity threshold and the speed of the terminal is greater than the speed threshold, it is determined that the terminal is moving at high speed.

9. The method according to claim 1, wherein The base station reallocates pilots, assigning the same pilots to terminals at the cell center, prioritizing the remaining orthogonal pilots to high-speed mobile terminals, and then assigning the remaining orthogonal pilots to terminals at the cell edge, including: The base station fixedly allocates the first pilot N1 in the orthogonal pilot sequence to the terminal at the cell center, and randomly allocates the pilots N2...Nm in the pilot sequence to high-speed mobile terminals. After allocating the high-speed mobile terminals, the remaining pilots in the pilot sequence N2...Nm are preferentially allocated to the first type of edge terminals. After allocating the first type of edge terminals, the remaining pilots are allocated to the second type of edge terminals, where N1...Nm are orthogonal pilot sequences and m is an integer greater than 1.

10. A pilot allocation method for a 5G MIMO system, characterized in that: include: The terminal measures the pilot signal assigned by the base station, calculates the terminal's location information and the signal-to-noise ratio of the pilot signal received by the terminal, and reports the location information and the signal-to-noise ratio of the pilot signal to the base station. The base station obtains the location information of the terminal and the signal-to-noise ratio of the terminal pilot; The base station allocates pilot signals to each terminal in the cell according to the terminal's location information and signal-to-noise ratio; The base station continuously acquires the pilot signal of each terminal at a certain time interval to obtain the precoding matrix of each terminal at different time points; The base station calculates the similarity of the precoding matrix of each terminal at different time points, and determines whether the similarity of the precoding matrix at different time points is greater than a similarity threshold; If it is greater than the similarity threshold, it is determined that the terminal is moving at high speed. The base station reallocates the pilots, allocates the same pilots to the terminals at the center of the cell, allocates the remaining orthogonal pilots to the terminals moving at high speed first, and then allocates the other orthogonal pilots to the terminals at the edge of the cell.

11. The method according to claim 10, wherein The base station allocates pilot signals to each terminal in the cell according to the terminal's location information and signal-to-noise ratio, including: The base station allocates a pilot in the orthogonal pilot sequence to all terminals located at the center of the cell covered by the base station; the remaining pilots are preferentially allocated to the first type of edge terminals, and the remaining pilots after the allocation to the first type of edge terminals are allocated to the second type of edge terminals. The terminals are divided into central terminals, first type of edge terminals, and second type of edge terminals based on their location information and signal-to-noise ratio.

12. The method according to claim 10, wherein The base station reallocates pilots, assigning the same pilots to terminals at the cell center, prioritizing the remaining orthogonal pilots to high-speed mobile terminals, and then assigning the remaining orthogonal pilots to terminals at the cell edge, including: The base station fixedly allocates the first pilot N1 in the orthogonal pilot sequence to the terminal at the cell center, and randomly allocates the pilots N2...Nm in the pilot sequence to high-speed mobile terminals. After allocating the high-speed mobile terminals, the remaining pilots in the pilot sequence N2...Nm are preferentially allocated to the first type of edge terminals. After allocating the first type of edge terminals, the remaining pilots are allocated to the second type of edge terminals, where N1...Nm are orthogonal pilot sequences and m is an integer greater than 1.

13. A pilot allocation device for a 5G MIMO system, characterized in that: It comprises a memory and a processor; the processor is used to execute the computer program stored in the memory to implement the steps of the pilot allocation method of the 5G MIMO system as described in any one of claims 1 to 12.

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