Super-large scale array simulation method and device based on wireless channel simulator

Abstract

The invention relates to a super-large scale array simulation method and device based on a wireless channel simulation instrument. The method comprises the following steps: quickly transmitting a phase sequence output by a phase shifter to the simulation instrument; the method comprises the following steps: discretely generating a track of a terminal, storing the track in a memory of a channel simulator, multiplying an additional phase of a phase shifter and a steering vector according to strict time synchronization, and outputting amplitude and phase gains brought by spatial correlation in an array unit; according to the single-array channel impact response at the moment t, generating a channel impact response of a single array in an array unit by utilizing a specified channel modeling method according to a terminal track; calculating a steering vector of an array in the array unit to each position of the UE; the data processing module performs dot product summation according to the phase shifter data transmitted by the high-speed interface and the array steering vector read from the memory; and the channel impact response and the input signal are multiplied to complete a fading channel simulation process, so that two-stage weight dynamic adjustment of the Massive MIMO system and a super-large-scale antenna array simulation test are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of large-scale array antennas, and in particular relates to a super-large-scale array simulation method and device based on a wireless channel simulator. Background Art

[0002] In large-scale array antenna technology, beamforming is an important part of array signal processing. From an engineering perspective, beamforming can be achieved through analog domain multi-antenna signal processing and digital domain multi-antenna signal processing. With the development of technology, hybrid beamforming technology that has both analog and digital domains has begun to show its advantages: it combines the advantages of analog and digital beamforming technologies, and can reduce hardware costs and signal processing complexity while approaching the optimal performance that can be achieved by a fully digital system.

[0003] The core idea of ​​hybrid beamforming is to divide the entire large array into multiple small sub-arrays, that is, each antenna unit is no longer completely independent. Each sub-array is an analog beamforming array, and the number of divided sub-arrays determines the beamforming freedom of the entire large array. In Massive MIMO communication technology, beam control can be achieved by adjusting the simulator weights of the sub-arrays and the digital weights of the entire array. When the center frequency of the azimuth plane is 2GHz, the sub-array analog weights can achieve a 45° beam offset, and the digital weights can achieve precise control of the beam at small angles.

[0004] Due to the use of conduction, the traditional wireless channel simulation test based on wireless channel emulator requires the removal of the antennas (panels) of the communicating parties. Channel modeling generally adopts a subarray pattern-based approach to realize the influence of fixed patterns brought about by changes in the positions of the communicating parties, that is, the simulation weights cannot be dynamically adjusted to achieve beamforming tests with a large coverage range. At the same time, with the evolution of 5G technology, the number of antennas on the base station side has reached thousands or even tens of thousands. Due to the limitations of signal processing capabilities and testing costs, wireless channel emulators need to innovate traditional testing methods to match the testing capabilities of ultra-large-scale antenna arrays on the base station side.

[0005] Therefore, how to improve the traditional wireless channel simulation test based on wireless channel emulator to realize the two-level weight dynamic adjustment and ultra-large-scale antenna array simulation test of Massive MIMO system is a technical problem that needs to be solved urgently. Summary of the invention

[0006] The object of the present invention is to provide a very large-scale array simulation method and device based on a wireless channel emulator, so as to realize two-level weight dynamic adjustment of a Massive MIMO system and a very large-scale antenna array simulation test.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] In the first aspect, a very large-scale array simulation device based on a wireless channel simulator is provided, which is used for a base station antenna array, and includes an array unit, an antenna array, a modeling software and a data processing module, wherein each of the array units is provided with an M×N unit array with the same antenna directional pattern, and the antenna array is provided at the base station side, and N bs ×M×N antenna arrays; each array unit is provided with a phase shifter, and the base station side provides 2N bs physical port.

[0009] In a second aspect, a method for simulating a very large-scale array based on a wireless channel emulator is provided, which is implemented based on a very large-scale array emulation device based on a wireless channel emulator, and is characterized in that it includes the following steps:

[0010] S1: The phase sequence output by the phase shifter is transmitted through the high-speed interface between the base station and the channel emulator 1≤m≤M,1≤n≤N is quickly transmitted to the simulator;

[0011] S2: g m,n ,1≤m≤M,1≤n≤N is discretely generated through the terminal trajectory and stored in the memory of the channel emulator. The additional phase of the phase shifter and the steering vector are multiplied according to strict time synchronization to output the amplitude and phase gain χ1 brought by the spatial correlation in the array unit;

[0012] S3: The single array channel impulse response χ2 at time t generates the channel impulse response of a single array in the array unit according to the terminal trajectory using the specified channel modeling method and stores it in the channel simulator;

[0013] S4: At time t, the simulator reads 1≤m≤M,1≤n≤N and g m,n ,1≤m≤M,1≤n≤N calculate χ1, and then multiply it with χ2 at time t to get the channel impulse response of the current array unit at point P;

[0014] S5: The modeling software calculates the guidance vectors of the M×N arrays in the array unit to each position of the UE according to the UE motion trajectory and the array spacing and writes them into the simulator memory;

[0015] S6: For a single array unit of the simulator, the data processing module performs point multiplication and summation based on the M×N phase shifter data transmitted from the high-speed interface and the M×N array steering vectors g read from the memory, that is, χ1 is realized;

[0016] S7: The simulator reads the channel impulse response χ2 generated by the single-array channel modeling in the memory, obtains the channel impulse response of the array unit by implementing χ1×χ2, and multiplies the channel impulse response by the input signal to complete the fading channel simulation.

[0017] Preferably, in step S3, χ2 generates a channel impulse response of a single array in the array unit according to the terminal trajectory using a channel modeling method specified in the 3GPP-38901 protocol.

[0018] Preferably, the calculation process of the amplitude and phase gain χ1 caused by the spatial correlation in the array unit in step S2 is:

[0019] S21: Based on the specified array unit, there is a specified far-field point P, whose spatial angle is Ω. The directivity patterns of the arrays in the array unit are the same. Then the received signal at point P under the plane wave condition is calculated. The specific formula is:

[0020]

[0021] Where x(t) represents the input signal at time t; F(Ω) represents the component of the directivity pattern of a single array in the array unit in the direction of the spatial angle Ω; g m,n ,1≤m≤M,1≤n≤N represents the steering vector of the array in the mth row and nth column in the array unit in the direction of the spatial angle Ω; 1≤m≤M,1≤n≤N represents the phase added by the phase shifter to the array in the mth row and nth column of the array unit; H(t) represents the complex impulse response brought by the wireless channel at time t;

[0022] S22: The calculation formula of the received signal at point P is sorted out to obtain:

[0023]

[0024] At time t, convert the above formula: p =x(t)×χ1×χ2;

[0025] in,

[0026]

[0027] χ2=F(Ω)×H(t);

[0028] χ1 represents the amplitude and phase gain brought by the spatial correlation in the array unit; χ2 represents the impulse response of a single array channel at time t.

[0029] Preferably, in step S3, the specific formula for generating the channel impulse response of a single array in the array unit by χ2 using the channel modeling method specified in the 3GPP-38901 protocol according to the terminal trajectory is as follows:

[0030]

[0031] in, represents the non-line-of-sight path, τ represents the multipath delay; Indicates the straight line diameter, K R is the Rice K factor, which represents the proportion of the LOS path in all paths. Each non-straight path is composed of 20 sub-paths.

[0032] Preferably, non-straight line of sight and direct viewing path The modeling method is as follows:

[0033]

[0034] Where u represents the antenna index of the receiving antenna; s represents the antenna index of the transmitting antenna; n represents the cluster index; m represents the subpath index; P n represents the normalized cluster power; M represents the number of subpaths; θ represents the elevation angle; Indicates azimuth; F rx,u, θ Represents the directional pattern of the receiving antenna in the vertical direction; represents the directional pattern of the receiving antenna in the horizontal direction; κ represents the cross-polarization ratio; Φ represents the random phase; Represents the coordinates of the receiving terminal in the spherical coordinate system; represents the coordinates of the transmitting base station in the spherical coordinate system; represents the coordinate vector of the u-th receiving antenna; represents the coordinate vector of the sth transmitting antenna; λ0 represents the wavelength; v represents the velocity vector of the terminal.

[0035] The beneficial effects of the present invention include:

[0036] The present invention provides a very large-scale array simulation method and device based on a wireless channel emulator, which quickly transmits the phase sequence output by the phase shifter to the emulator; generates it discretely through the trajectory of the terminal and stores it in the memory of the channel emulator, and multiplies the additional phase of the phase shifter and the steering vector according to strict time synchronization to output the amplitude and phase gain brought by the spatial correlation in the array unit; generates the channel impulse response of a single array in the array unit at time t according to the terminal trajectory using a specified channel modeling method; calculates the steering vector of the array in the array unit for each position of the UE; the data processing module performs point multiplication and summation based on the phase shifter data transmitted by the high-speed interface and the array steering vector read from the memory; obtains the channel impulse response of the array unit, and multiplies the channel impulse response and the input signal to complete the process of fading channel simulation, thereby realizing the two-level weight dynamic adjustment of the Massive MIMO system and the very large-scale antenna array simulation test. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the base station antenna array of the present invention.

[0038] Figure 2 It is a schematic diagram of the array unit and the phase shifter of the present invention.

[0039] Figure 3 Schematic diagram of the far-field plane wave of the present invention.

[0040] Figure 4 This is a block diagram of the implementation of the real-time channel response of a single port (array unit) of the simulator of the present invention. DETAILED DESCRIPTION

[0041] The following is combined with Figure 1 to Figure 4 The present invention is further described in detail:

[0042] Example 1

[0043] See attached Figure 1 As shown, a super-large-scale array simulation device based on a wireless channel simulator is used for a base station antenna array, including an array unit, an antenna array, a modeling software and a data processing module. Each of the array units is provided with an M×N unit array with the same antenna directional pattern. The antenna array is arranged at the base station side. N bs ×M×N antenna arrays; each array unit is provided with a phase shifter, and the base station side provides 2N bs Assuming that the base station is dual-polarized and adopts the conduction test method, if the fading channel simulation of M×N antennas can be realized with one physical port through signal processing, the wireless channel simulator only needs to provide 2N bs This greatly reduces the cost and complexity of emulator testing.

[0044] See also Figure 1-Figure 3 As shown, a method for simulating a very large-scale array based on a wireless channel emulator is implemented based on the very large-scale array emulation device based on a wireless channel emulator, and is characterized in that it includes the following steps:

[0045] S1: The phase sequence output by the phase shifter is transmitted through the high-speed interface between the base station and the channel emulator 1≤m≤M,1≤n≤N is quickly transmitted to the simulator;

[0046] S2: g m,n ,1≤m≤M,1≤n≤N is discretely generated through the terminal trajectory and stored in the memory of the channel emulator. The additional phase of the phase shifter and the steering vector are multiplied according to strict time synchronization to output the amplitude and phase gain χ1 brought by the spatial correlation in the array unit;

[0047] S3: The single array channel impulse response χ2 at time t generates the channel impulse response of a single array in the array unit according to the terminal trajectory using the specified channel modeling method and stores it in the channel simulator;

[0048] S4: At time t, the simulator reads 1≤m≤M,1≤n≤N and g m,n ,1≤m≤M,1≤n≤N calculate χ1, and then multiply it with χ2 at time t to get the channel impulse response of the current array unit at point P;

[0049] S5: The modeling software calculates the guidance vectors of the M×N arrays in the array unit to each position of the UE according to the UE motion trajectory and the array spacing and writes them into the simulator memory;

[0050] S6: For a single array unit of the simulator, the data processing module performs point multiplication and summation based on the M×N phase shifter data transmitted from the high-speed interface and the M×N array steering vectors g read from the memory, that is, χ1 is realized;

[0051] S7: The simulator reads the channel impulse response χ2 generated by the single-array channel modeling in the memory, obtains the channel impulse response of the array unit by implementing χ1×χ2, and multiplies the channel impulse response by the input signal to complete the fading channel simulation.

[0052] A high-speed interface device is added to the traditional wireless channel emulator to meet the needs of the χ1 emulator to realize real-time functions, that is, the phase sequence output by the phase shifter is converted to 1≤m≤M,1≤n≤N is quickly transmitted to the simulator; g m,n ,1≤m≤M,1≤n≤N is discretely generated through the terminal trajectory and stored in the memory of the channel emulator. The additional phase of the phase shifter and the steering vector are multiplied according to strict time synchronization to output χ1; χ2 is generated according to the terminal trajectory using the channel modeling method specified in the 3GPP-38901 protocol to generate the channel impulse response of a single array in the array unit and stored in the channel emulator. At time t, the emulator reads 1≤m≤M,1≤n≤N and g m,n ,1≤m≤M,1≤n≤N calculate χ1, and then multiply it with χ2 at time t to get the channel impulse response of the current array unit at point P. The implementation principle is as follows Figure 4 shown.

[0053] In this embodiment, the modeling software calculates the steering vectors of the M×N arrays in the array unit for each UE position according to the UE motion trajectory and the array spacing and writes them into the simulator memory. For a single port (single array unit) of the simulator, the data processing module performs point multiplication and summation based on the M×N phase shifter data transmitted from the high-speed interface and the steering vectors g of the M×N arrays read from the memory, that is, implements χ1; the channel impulse response χ2 generated by the single array channel modeling is read from the simulator memory, and the channel impulse response of the array unit is obtained by implementing χ1×χ2. Multiplying the channel impulse response and the input signal completes the fading channel simulation.

[0054] Example 3

[0055] On the basis of Embodiment 1 or Embodiment 2, in step S3, χ2 generates a channel impulse response of a single array in the array unit according to the terminal trajectory using a channel modeling method specified in the 3GPP-38901 protocol.

[0056] The calculation process of the amplitude and phase gain χ1 caused by the spatial correlation in the array unit in step S2 is:

[0057] S21: Based on the specified array unit, there is a specified far-field point P, whose spatial angle is Ω. The directivity patterns of the arrays in the array unit are the same. Then the received signal at point P under the plane wave condition is calculated. The specific formula is:

[0058]

[0059] Where x(t) represents the input signal at time t; F(Ω) represents the component of the directivity pattern of a single array in the array unit in the direction of the spatial angle Ω; g m,n ,1≤m≤M,1≤n≤N represents the steering vector of the array in the mth row and nth column in the array unit in the direction of the spatial angle Ω; 1≤m≤M,1≤n≤N represents the phase added by the phase shifter to the array in the mth row and nth column of the array unit; H(t) represents the complex impulse response brought by the wireless channel at time t;

[0060] S22: The calculation formula of the received signal at point P is sorted out to obtain:

[0061]

[0062] At time t, convert the above formula: p =x(t)×χ1×χ2;

[0063] in,

[0064]

[0065] χ2=F(Ω)×H(t);

[0066] χ1 represents the amplitude and phase gain brought by the spatial correlation in the array unit; χ2 represents the impulse response of a single array channel at time t.

[0067] In this embodiment, in step S3, the specific formula for generating the channel impulse response of a single array in the array unit by χ2 using the channel modeling method specified in the 3GPP-38901 protocol according to the terminal trajectory is as follows:

[0068]

[0069] in, represents the non-line-of-sight path, τ represents the multipath delay; Indicates the straight line diameter, K R is the Rice K factor, which represents the proportion of the LOS path in all paths. Each non-straight path is composed of 20 sub-paths.

[0070] Non-sight path and direct viewing path The modeling method is as follows:

[0071]

[0072] Where u represents the antenna index of the receiving antenna; s represents the antenna index of the transmitting antenna; n represents the cluster index; m represents the subpath index; P n represents the normalized cluster power; M represents the number of subpaths; θ represents the elevation angle; Indicates azimuth; F rx,u, θ Represents the directional pattern of the receiving antenna in the vertical direction; represents the directional pattern of the receiving antenna in the horizontal direction; κ represents the cross-polarization ratio; Φ represents the random phase; Represents the coordinates of the receiving terminal in the spherical coordinate system; represents the coordinates of the transmitting base station in the spherical coordinate system; represents the coordinate vector of the u-th receiving antenna; represents the coordinate vector of the sth transmitting antenna; λ0 represents the wavelength; v represents the velocity vector of the terminal.

[0073] The above non-sight path and direct viewing path The formula of the modeling method shows that the impact of the array unit can be divided into two parts: χ1 and χ2.

[0074] It shows that the calculation of χ1 requires the steering vector and the additional phase of the phase shifter (simulation weight). The simulator weight of the base station changes in real time, so the simulator needs to respond in real time. The steering vector can be obtained based on the geometric relationship between the base station and the terminal.

[0075] The impact of χ2 is expressed by the formula:

[0076] Channel modeling implementation.

[0077] In summary, the ultra-large-scale array simulation method and device based on a wireless channel emulator provided by the present invention quickly transmits the phase sequence output by the phase shifter to the emulator; the phase sequence is discretely generated through the terminal trajectory and stored in the memory of the channel emulator, and the additional phase of the phase shifter and the steering vector are multiplied according to strict time synchronization to output the amplitude and phase gain brought by the spatial correlation in the array unit; the channel impulse response of a single array at time t is generated according to the terminal trajectory using a specified channel modeling method; the steering vector of the array in the array unit to each position of the UE is calculated; the data processing module performs point multiplication and summation based on the phase shifter data transmitted by the high-speed interface and the array steering vector read from the memory; the channel impulse response of the array unit is obtained, and the channel impulse response and the input signal are multiplied to complete the fading channel simulation process, thereby realizing the two-level weight dynamic adjustment of the Massive MIMO system and the ultra-large-scale antenna array simulation test.

Claims

1. A super-large-scale array simulation device based on a wireless channel simulator, characterized in that: For base station antenna array, including array unit, antenna array, modeling software and data processing module, each array unit is provided with M×N antenna array with the same directional pattern, the antenna array is arranged at the base station side, and N bs ×M×N antenna arrays; each of the array units is provided with a phase shifter, and the base station side provides 2N bs physical port.

2. A method for simulating a very large array based on a wireless channel emulator, implemented based on the very large array emulation device based on a wireless channel emulator according to claim 1, characterized in that: The following steps are involved: S1: The phase sequence output by the phase shifter is transmitted through the high-speed interface between the base station and the channel emulator 1≤m≤M,1≤n≤N is quickly transmitted to the simulator; S2: g m,n ,1≤m≤M,1≤n≤N is discretely generated through the terminal trajectory and stored in the memory of the channel emulator. The additional phase of the phase shifter and the steering vector are multiplied according to strict time synchronization to output the amplitude and phase gain χ1 brought by the spatial correlation in the array unit; S3: The single array channel impulse response χ2 at time t generates the channel impulse response of a single array in the array unit according to the terminal trajectory using the specified channel modeling method and stores it in the channel simulator; S4: At time t, the simulator reads 1≤m≤M,1≤n≤N and g m,n ,1≤m≤M,1≤n≤N calculate χ1, and then multiply it with χ2 at time t to get the channel impulse response of the current array unit at point P; S5: The modeling software calculates the guidance vectors of the M×N arrays in the array unit to each position of the UE according to the UE motion trajectory and the array spacing and writes them into the simulator memory; S6: For a single array unit of the simulator, the data processing module performs point multiplication and summation based on the M×N phase shifter data transmitted from the high-speed interface and the M×N array steering vectors g read from the memory, that is, χ1 is realized; S7: The simulator reads the channel impulse response χ2 generated by the single-array channel modeling in the memory, obtains the channel impulse response of the array unit by implementing χ1×χ2, and multiplies the channel impulse response by the input signal to complete the fading channel simulation.

3. The ultra-large-scale array simulation method based on a wireless channel simulator according to claim 2, characterized in that: In step S3, χ2 generates a channel impulse response of a single array in the array unit according to the terminal trajectory using the channel modeling method specified in the 3GPP-38901 protocol.

4. A very large-scale array simulation method based on a wireless channel simulator according to claim 3, characterized in that: The calculation process of the amplitude and phase gain χ1 caused by the spatial correlation in the array unit in step S2 is: S21: Based on the specified array unit, there is a specified far-field point P, whose spatial angle is Ω. The directivity patterns of the arrays in the array unit are the same. Then the received signal at point P under the plane wave condition is calculated. The specific formula is: Where x(t) represents the input signal at time t; F(Ω) represents the component of the directivity pattern of a single array in the array unit in the direction of the spatial angle Ω; g m,n ,1≤m≤M,1≤n≤N represents the steering vector of the array in the mth row and nth column in the array unit in the direction of the spatial angle Ω; 1≤m≤M,1≤n≤N represents the phase added by the phase shifter to the array in the mth row and nth column of the array unit; H(t) represents the complex impulse response brought by the wireless channel at time t; S22: The calculation formula of the received signal at point P is sorted out to obtain: At time t, convert the above formula: p =x(t)×χ1×χ2; in, χ1 represents the amplitude and phase gain brought by the spatial correlation in the array unit; χ2 represents the impulse response of a single array channel at time t.

5. A very large-scale array simulation method based on a wireless channel simulator according to claim 4, characterized in that: In step S3, the specific formula for generating the channel impulse response of a single array in the array unit by χ2 using the channel modeling method specified in the 3GPP-38901 protocol according to the terminal trajectory is as follows: in, represents the non-line-of-sight path, τ represents the multipath delay; Indicates the straight line diameter, K R is the Rice K factor, which represents the proportion of the LOS path in all paths. Each non-straight path is composed of 20 sub-paths.

6. A very large-scale array simulation method based on a wireless channel simulator according to claim 5, characterized in that: Non-sight path and direct viewing path The modeling method is as follows: Where u represents the antenna index of the receiving antenna; s represents the antenna index of the transmitting antenna; n represents the cluster index; m represents the subpath index; P n represents the normalized cluster power; M represents the number of subpaths; θ represents the elevation angle; Indicates azimuth; F rx,u, θ Represents the directional pattern of the receiving antenna in the vertical direction; represents the directional pattern of the receiving antenna in the horizontal direction; κ represents the cross-polarization ratio; Φ represents the random phase; Represents the coordinates of the receiving terminal in the spherical coordinate system; represents the coordinates of the transmitting base station in the spherical coordinate system; represents the coordinate vector of the u-th receiving antenna; represents the coordinate vector of the sth transmitting antenna; λ0 represents the wavelength; v represents the velocity vector of the terminal.

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