CN105897351A - Uplink and downlink wave beam shaping measure system and method - Google Patents

Abstract

The invention provides an uplink and downlink beamforming measurement system and method, which are used to obtain the transfer matrix of a complete beamforming system through one-time measurement based on software radio technology. The system includes: the transmitting end of the uplink beamforming system, the transmitting channel is simultaneously connected to the calibration channel of the transmitting channel amplitude-phase consistency calibration network and the receiving channel of the feed array of the uplink beamforming network; the transmitting channel amplitude-phase consistency calibration network adopts An online calibration mode; and the receiving end of the downlink beamforming system, the receiving channel is connected to the transmitting channel of the feed array of the downlink beamforming network. Therefore, by adopting the present invention, the accuracy of the amplitude and phase information of the multi-channel sinusoidal signals sent by the sending end is ensured, and the calibration of the sending feed source signal can be carried out simultaneously with the test of the receiving feed source signal, thereby improving the test efficiency of the test system and effectively reducing the Test effort and test system complexity.

Description

Uplink and downlink beamforming measurement system and method

technical field

The invention belongs to the field of digital signal processing, and relates to software radio technology, in particular to a dedicated measurement scheme for uplink and downlink beamforming based on software radio methods, and more specifically, to a measurement system and method for uplink and downlink beamforming for software radio technology. , a one-shot measurement to obtain the transfer matrix of the complete beamforming system.

Background technique

The antenna array is composed of a large number of array units (referred to as "array elements"), each array element is located in a different position in space, and forms an array according to certain rules. Compared with the unit antenna, the antenna array can effectively enhance the directivity of the antenna and increase the antenna gain at the same time. The core technology of the array antenna is beam forming (Beam-Forming, hereinafter referred to as BF)

Beamforming technology is to set complex weighting coefficients that can be dynamically adjusted in real time on each array element of the antenna array. By adjusting the complex weighting coefficients, the current amplitude and phase distribution of the antenna array are adjusted to achieve flexible control of the direction of each beam of the antenna array. , and optimize its pattern shape.

Taking the uplink (receiving) antenna array as an example, the uplink beamforming network can align the main lobe of the pattern with the direction of the useful signal, and align the null of the pattern with the direction of the interference signal, thereby maximizing the signal-to-interference ratio of the received signal . For the downlink (transmit) antenna array, the downlink beamforming network can form multiple beams in different directions, effectively increasing the transmit power in a designated area and increasing the satellite downlink margin. From the perspective of signal processing, the uplink and downlink beamforming system is a spatial filter.

In the satellite communication system, the beamforming system is mainly composed of three parts: antenna array, transceiver feed channel, digital-to-analog/analog-to-digital conversion, and digital signal processor. The beamforming technology realizes the uplink and downlink beam switching of satellites by adjusting the feed complex weighting parameters generated by the digital signal processor in real time in the uplink and downlink forming network. A dynamic connection matrix is used to interconnect the corresponding uplink and downlink beams as needed to meet the communication requirements between ground stations within the coverage of the beams.

In order to evaluate the quality of uplink and downlink beamforming, it is necessary to measure the amplitude (degree) phase (phase) transfer relationship between the uplink input feed array and the downlink output feed array. The traditional test method of uplink and downlink beamforming system mainly relies on the general test equipment - vector network analyzer, that is, the amplitude-phase relationship between a certain uplink feed source and a certain downlink feed source is measured by the vector network analyzer, among which, the vector network analysis The instrument measures the transfer function of the uplink and downlink beamforming network, and the value of the transfer function at the set carrier frequency is the amplitude-phase relationship to be sought.

During the measurement, except for a pair of uplink and downlink feeds to be tested, the remaining (N×M-2) feeds must be terminated with matching loads. Assuming that the numbers of uplink and downlink array elements are N and M respectively, a total of N×M amplitude-phase relationships need to be measured using a vector network analyzer. The measurement process needs to frequently adjust the connection relationship of the cables, resulting in heavy workload and low test efficiency. However, if it is necessary to change the carrier frequency of the signal in the array element, the entire test work must be repeated again. As the number of array elements in the antenna array system continues to increase and the signal bandwidth of the array elements increases, it is becoming more and more difficult to measure the amplitude and phase distribution of the uplink and downlink beamforming systems with a vector network analyzer, and the test complexity is getting higher and higher.

Therefore, there is an urgent need for a truly reasonable test system that can take into account the application background of the uplink and downlink beamforming systems, and has N outputs and M inputs corresponding to the N inputs and M outputs of the beamforming system under test. The test system configures the amplitude-phase relationship of the N output signals to make it consistent with the amplitude-phase relationship formed by the specific incident direction signal on the N input feed sources of the uplink beamforming system in the real environment, so as to ensure that the beam signal is relative to the uplink receiving antenna. The array exhibits a preset angle of incidence. At the same time, the test equipment receives M outputs of the downlink beamforming system, measures the amplitude-phase relationship between the M output signals, and compares them with the expected amplitude-phase distribution values of the uplink and downlink beamforming systems to finally determine the beamforming error.

Contents of the invention

In order to solve the problems existing in the prior art, the present invention proposes an uplink and downlink beamforming measurement scheme based on a software radio method, which is characterized in that the sending end of the uplink beamforming system uses a field programmable gate array (Field Programmable Gate Array, hereinafter referred to FPGA) + digital-to-analog converter (Digtial to Analog Converter, hereinafter referred to as DAC) structure, the receiving end of the online calibration and downlink beamforming system uses FPGA + analog-to-digital converter (Analog to Digital Converter, hereinafter referred to as ADC) The structure adopts a method that is completely consistent with the actual working conditions of the uplink and downlink beamforming systems. Only one measurement can accurately measure the transfer matrix of the complete beamforming system, which has high test accuracy and effectively reduces test complexity.

One aspect of the present invention provides an uplink and downlink beamforming measurement system, which is used for obtaining a transfer matrix of a complete beamforming system through one-time measurement based on software radio technology. The system includes: the transmitting end of the uplink beamforming system, the transmitting channel is simultaneously connected to the calibration channel of the transmitting channel amplitude-phase consistency calibration network and the receiving channel of the feed array of the uplink beamforming network; the transmitting channel amplitude-phase consistency calibration network adopts An online calibration mode; and the receiving end of the downlink beamforming system, the receiving channel is connected to the transmitting channel of the feed array of the downlink beamforming network.

Specifically, the transmitting end of the uplink beamforming system adopts the structure of field programmable gate array + digital-to-analog converter, and the amplitude-phase consistency calibration network of the transmitting channel and the receiving end of the downlink beamforming system adopt field programmable gate array + analog Structure of the digitizer.

Preferably, at the transmitting end of the uplink beamforming system, the field programmable gate array is used to control the amplitude of the beam sinusoidal signal to be transmitted in its transmission channel, and to adjust the phase of the beam sinusoidal signal by means of direct digital frequency synthesis , wherein the beam sinusoidal signal is processed to generate a test excitation signal and the test excitation signal is sent to the uplink beamforming network. The test excitation signal is also fed into the sending channel amplitude-phase consistency calibration network through the power divider.

In addition, the transmission channel amplitude-phase consistency calibration network receives the uplink signal sent by the test system to the uplink beamforming system and measures the amplitude-phase inconsistency introduced by the power amplifier of the active device between the transmission feeds to provide the transmission end of the test system Real-time amplitude and phase calibration. The receiving end of the downlink beamforming system is used to receive the downlink element signals output by the downlink beamforming system and measure their amplitude-phase relationship.

Another aspect of the present invention also provides a method for measuring uplink and downlink beamforming, which includes the following steps: step 1, according to the incident angle preset by the beam signal relative to the uplink receiving antenna array, at the transmitting end of the uplink beamforming system, Adopt the signal processing method of field programmable gate array + digital-to-analog converter to configure the amplitude-phase relationship of the beam signal in the transmission channel of the sinusoidal signal; step 2, in the transmission channel amplitude-phase consistency calibration network, use the field programmable gate array + The signal processing method of the analog-to-digital converter measures the relative amplitude-phase relationship of the sinusoidal signal in the calibration channel as the amplitude-phase relationship of the input feed signal of the uplink antenna array; Step 3, at the receiving end of the downlink beamforming system, adopt Field programmable gate array + analog-to-digital converter signal processing method, receive and measure the amplitude-phase relationship of the sinusoidal signal in the receiving channel, as the amplitude-phase relationship of the output feed signal of the downlink antenna array; and step 4, according to the uplink antenna The amplitude-phase relationship of the array input feed signal and the amplitude-phase relationship of the downlink antenna array output feed signal are calculated to obtain the transfer function played by the uplink and downlink beamforming, so as to obtain the transfer matrix of the complete beamforming system.

In addition, the uplink and downlink beamforming measurement method of the present invention also includes: feeding back the relative amplitude-phase relationship of the feed signal measured by the amplitude-phase consistency calibration network of the transmission channel as the calibration amplitude-phase relationship to the transmission of the uplink beamforming system and the transmitting end of the uplink beamforming system compares the calibrated amplitude-phase relationship with the amplitude-phase relationship of the transmitted sinusoidal signal, and adjusts the amplitude and phase of the sinusoidal signal in the transmission channel in real time according to the error.

In step 2, it includes: realizing the data acquisition of the received feed signal through the analog-to-digital converter and obtaining the intermediate frequency digital signal after sampling and quantizing, and inputting the field programmable gate array; the field programmable gate array performs orthogonal Down-conversion processing, so as to ensure that the relative phase of the input signal of each calibration channel in the calibration network of the sending channel amplitude and phase is not affected by the down-converter and ensure the two-way orthogonality of the output quadrature signal; The cosine matched filter performs root-raised cosine matched filter processing on the signal after quadrature down-conversion processing, so as to obtain the relative amplitude-phase relationship of each feed signal.

In addition, in step 2, it may also include: taking the signal with the strongest power as a reference signal, and performing coherent cumulative average calculation on the decision statistics output by the root-raised cosine matched filter, so as to overcome the additive white Gaussian noise in the test process, and Accurate relative amplitude-phase relationships are obtained.

Therefore, adopt the present invention to design the uplink and downlink beamforming measurement system based on the software radio method, adopt the structure of FPGA+DAC at the sending end in combination with the FPGA+ADC at the receiving end, and can adjust the amplitude and phase of the sending feed source signal in real time, and the amplitude and phase The fine-tuning resolution can be improved by increasing the bit width of the digital signal sent to the digital-to-analog conversion DAC and the storage depth and bit width of the DDS lookup table in the digital up-conversion, thereby ensuring the accuracy of the amplitude and phase information of the multi-channel sinusoidal signal sent by the sending end .

Secondly, the test scheme of the present invention has the function of calibrating the amplitude and phase consistency of the transmission channel, which compensates and basically eliminates the inconsistency of the amplitude and phase of the transmission channel introduced by the analog circuit affected by temperature drift and aging. The calibration of the sending feed source signal does not affect the normal operation of the system measurement, and can be carried out simultaneously with the test of the receiving feed source signal, and there is no need to send a reference signal to achieve calibration, which improves the test efficiency of the test system.

In addition, the test of the N×M dimensional amplitude-phase transfer matrix of the uplink and downlink beamforming system can be accurately measured only once, and there is no need to adjust external connecting lines. If you need to change the carrier frequency of the signal in the sending feed, you only need to adjust the step of the frequency control word in the digital up-conversion DDS through digital signal processing, which effectively reduces the test workload and test system complexity.

Description of drawings

Fig. 1 is a system block diagram of a satellite uplink beamforming system according to a specific embodiment of the present invention;

2 is a system block diagram of a satellite downlink beamforming system according to a specific embodiment of the present invention;

3 is a schematic diagram of the system composition of the uplink and downlink beamforming dedicated measurement system involved in the present invention;

Fig. 4 is the intermediate frequency digital signal processing flow chart of sending end according to the specific embodiment of the present invention;

Fig. 5 is the intermediate frequency digital signal processing flowchart of the receiving terminal according to the specific embodiment of the present invention; And

Fig. 6 is a flowchart of intermediate frequency digital signal processing of the verification network according to a specific embodiment of the present invention.

detailed description

The present invention will be described in detail below in conjunction with accompanying drawings 1-6 and specific embodiments. Specifically, Figure 1 is a system block diagram of the satellite uplink beamforming system, Figure 2 is a system block diagram of the satellite downlink beamforming system, Figure 3 is a schematic diagram of the system composition of the dedicated measurement system for uplink and downlink beamforming, and Figure 4 is the IF digital Signal processing flow chart, Fig. 5 is a flow chart of intermediate frequency digital signal processing at the receiving end, and Fig. 6 is a flow chart of intermediate frequency digital signal processing of the verification network.

As shown in FIG. 3 , the uplink and downlink beamforming measurement system involved in the present invention consists of three modules, namely, the transmitting end of the uplink beamforming system, the calibration network for the amplitude-phase consistency of the transmitting channel, and the receiving end of the downlink beamforming system. Among them, the transmission channels 1-N of the transmitting end of the uplink beamforming system are connected to the N calibration channels of the calibration network and the N receiving channels of the feed array of the uplink beamforming network, and the receiving channels 1-M of the receiving end of the downlink beamforming system are connected to the downlink beamforming system. M sending channels of the network feed array are formed.

As shown in Figure 1, at the transmitting end of the uplink beamforming system, the structure of FPGA+DAC is adopted, and the amplitude of the beam sinusoidal signal in each channel is controlled by FPGA and Direct Digital Synthesizer (hereinafter referred to as DDS) Fine-tune the phase of the sine wave to generate N test stimuli and send them to the uplink beamforming network. At the same time, the test excitation signal is fed into the sending channel amplitude-phase consistency calibration network through the power divider.

The online calibration network adopts the structure of FPGA+ADC, receives N uplink signals sent by the test system to the uplink beamforming system, and measures the amplitude-phase inconsistency introduced by the power amplifier of the active device between the transmission feed sources to provide a test system for the transmission of the test system. The terminal provides real-time amplitude and phase calibration.

As shown in Figure 2, the receiving end of the test system adopts the FPGA+ADC structure to receive M downlink array element signals output by the downlink beamforming system, and measure their amplitude-phase relationship.

It should be understood that the steps of the dedicated measurement method for uplink and downlink beamforming involved in the present invention are generally:

Step 1. According to the preset incident angle of the beam signal relative to the uplink receiving antenna array, use the signal processing method of FPGA+DAC to configure the amplitude-phase relationship {A _{R, n} , θ _R of the sinusoidal signal of the beam signal in the N transmission channels _{, n} |n=1, 2,..., N};

Step 2. Use the signal processing method of FPGA+ADC in the calibration network to measure the relative amplitude-phase relationship {A _{C, n} , θ _{C, n} |n=1, 2, ..., N} of the N sinusoidal signals in the calibration channel ;

Step 3: Measure the amplitude-phase relationship between the sending feeds according to the calibration network, and feed back to the sending end to adjust the amplitude-phase relationship of the sending feed signals;

Step 4: Adopt the FPGA+ADC signal processing method at the receiving end of the test system to receive and measure the amplitude-phase relationship {A _{S, m} , θ _{S, m} |m=1, 2, ... of sinusoidal signals in M receiving channels , M}; and

Step 5. According to the calibration network in the test system, the amplitude-phase relationship {A _{C, n} , θ _{C, n} |n=1, 2, ..., N} of the input feed signals of the N uplink antenna arrays and the measured value at the receiving end The amplitude-phase relationship {A _{S, m} , θ _{S, m} |m=1, 2, ..., M} of the output feed signals of the M downlink antenna arrays is used to obtain the transfer function of the uplink and downlink beamforming network.

Next, assume that the N-dimensional signal vector input to the uplink front of the uplink beamforming system is r(t)=[r ₁ (t), r ₂ (t),..., r _N (t)] ^T , where r _n (t) is the complex baseband signal received by the nth uplink feed source, n=1, 2, . . . , N. The process of uplink beamforming can be expressed as:

q(t)=v ^H r(t)

Among them, v is the N×1-dimensional uplink beamforming complex weighting coefficient, and the nth element v _n =|v _n |·exp{j·arg(v _n )} represents the amplitude gain of r _n (t)|v _n |, phase rotation arg(v _n ) radians.

The uplink beamforming performs spatial filtering on the input of the uplink antenna array, extracts the beam signal, and then performs downlink beamforming. The signal vector output by the M-dimensional downlink front is s( ^t ), which can be expressed as:

s(t)=u·q(t)

Wherein, u is an M×1-dimensional downlink beamforming complex gain vector.

Therefore, the transfer function matrix of the uplink and downlink beamforming system is: T=u·v ^H .

The purpose of the uplink and downlink beamforming measurement system based on the software radio method is to measure the signal vector r(t) of the input uplink front through the calibration network and the signal vector s(t) output by the downlink front measured by the receiver, and obtain the beam M×N-dimensional transfer function matrix of the forming system:

T=s(t)·r ^-1 (t)

Next, the uplink and downlink beamforming measurement method involved in the present invention will be described in detail with reference to Figures 4-6, and the specific steps are as follows:

Step 1. According to the preset incident angle of the beam signal relative to the uplink receiving antenna array, use the signal processing method of FPGA+DAC to configure the amplitude-phase relationship {A _{R, n} , θ _R of the sinusoidal signal of the beam signal in the N transmission channels _{, n} |n=1, 2,..., N}.

As shown in Figure 4, the N transmission channels of the test system simulate the N feeds of the receiving antenna array of the uplink beamforming system, and each transmission channel is composed of FPGA digital signal processor + digital-to-analog converter DAC.

Since the test system is not aimed at high-speed, error-free data transmission, but to extract the amplitude and phase information of the transfer function matrix of the beamforming system, the baseband generated signal at the sending end adopts all 0 or all 1 BPSK modulation. The baseband signal is digitally up-converted by using the DDS method: the amplitude information of a complete period of sine/cosine wave sampling and quantization is stored in the phase lookup table, and each address in the lookup table represents a certain phase point of the sine wave. The quantized magnitude corresponding to this phase. In the DDS, the phase look-up table operation is completed by intercepting the high-order bits of the frequency control word, so as to obtain the corresponding amplitude of the current phase. Through the phase accumulation operation, the DDS outputs a sinusoidal signal with a set center frequency. Change the selection address of the initial phase in the DDS phase lookup table to realize the configuration of the relative phase of the single-beam sinusoidal signal in the transmission channel.

Suppose the storage data bit width of the phase lookup table is 14bit, and the depth is 1024, therefore, the phase resolution in the lookup table is Assuming that the relative phases of the sinusoidal signals output by the N sending channels are θ _{R, 1} , θ _{R, 2} , ... θ _{R, N} , then the initial search address of the phase lookup table for generating the IF signal of the i-th sending channel is If the phase information of each sinusoidal signal in the preset sending feed is Then the initial address of the phase lookup table for generating the IF signal in the first feed channel is 0, and the initial address of the lookup table for generating the signal of the second feed channel is The initial address of the lookup table that generates the Nth feed channel signal is $\frac{\frac{\mathrm{\π}}{2}\×1024}{2\mathrm{\π}}=256.$

Through power control of the generated N intermediate frequency signals, configuration of relative power of single-beam sinusoidal signals in multiple transmission channels is realized. Let the relative power of the sinusoidal signals output by the N transmission channels be A _R,1 , _AR,2 ,...A _R,N , select the most powerful transmission signal as the reference signal, and set its amplitude weighting coefficient to 1. For non-reference signals in the FPGA, the attenuation of the signal amplitude is realized by shifting the data to the right. If the power information of each sinusoidal signal in the preset sending feed is [A _{R, 1} , A _{R, 2} , ... A _{R, N} ] = [0dB, -3dB, ..., -9dB], without loss of generality, select Send channel 1 as the reference channel, then shift the IF signal output by the second feed source to the right by 1 bit to achieve a 3dB amplitude attenuation, and shift the IF signal output from the Nth feed source to the right by 3 bits to achieve a 9dB amplitude attenuation. Finally, the single-beam sinusoidal signal configured with amplitude and phase distribution information is output from the DAC and fed into each transmission channel.

Step 2. Use the signal processing method of FPGA+ADC in the calibration network to measure the relative amplitude-phase relationship {A _{C, n} , θ _{C, n} |n=1, 2, ..., N} of the N sinusoidal signals in the calibration channel .

Because the amplitude-phase consistency of the transmission channel is affected by the analog RF device in the transmission channel—the power amplifier, the sub-frequency/phase-frequency characteristics of the power amplifier are highly discrete and vary with environmental factors such as temperature. Therefore, a calibration network is introduced in the test system to eliminate the inconsistency of the amplitude and phase of the transmission channel. As shown in Figure 5, the output signal of the sending end is fed into the calibration channel of the calibration network through the power divider. The calibration network uses an analog-to-digital converter ADC to realize data acquisition of N feed signal, and the intermediate frequency digital signal after sampling and quantization is input to FPGA . At the same time, the quadrature down-conversion is performed on the N-channel digital intermediate frequency signals to ensure that the relative phase of the input signals of each calibration channel is not affected by the down-converter, and to ensure the orthogonality of the output quadrature signal I/Q. Root-raised cosine matched filtering is performed on the 2N-channel signals output by digital down-conversion.

In order to overcome the additive white Gaussian noise in the test system, it is necessary to perform cumulative averaging on the 2N decision statistics output by the root-raised cosine matched filter. Coherent cumulative averaging refers to the vector superposition of the decision statistics of each information symbol period to improve the accuracy of the orthogonal I/Q two-way signals. For each pair of quadrature I/Q signals via The signal amplitude information is extracted by operation, and the signal phase information is extracted by arctan (Q/1) operation. Select the signal with the strongest power as the reference signal, and measure the relative amplitude and phase information {A _{C, n} , θ _{C, n} |n=1, 2,..., N} of each feed signal.

Step 3: The amplitude-phase relationship between the transmitting feed sources is measured according to the calibration network, and fed back to the transmitting end for adjusting the amplitude-phase relationship of the transmitting feed source signals.

The relative amplitude and phase information of each feed signal measured by the calibration network is fed back to the sending end. The sending end adjusts the amplitude and phase of the sinusoidal signal in the sending channel in real time according to the error between the sending amplitude and phase information and the calibration amplitude and phase information.

Step 4: Adopt the FPGA+ADC signal processing method at the receiving end of the test system to receive and measure the amplitude-phase relationship {A _{S, m} , θ _{S, m} |m=1, 2, ... of sinusoidal signals in M receiving channels , M}.

As shown in Figure 6, M receiving channels of the test system receive M feed signals output by the transmitting antenna array of the downlink beamforming system, and each receiving channel is composed of FPGA digital signal processor + analog-to-digital converter ADC. It should be understood that the digital signal processing flow at the receiving end is consistent with the calibration network.

Step 5. According to the calibration network in the test system, the amplitude-phase relationship {A _{C, n} , θ _{C, n} |n=1, 2, ..., N} of the N input uplink antenna array feed signal and the measured value at the receiving end The amplitude-phase relationship {A _{S, m} , θ _{S, m} |m=1, 2, ..., M} of the output feed signals of the M downlink antenna arrays is used to obtain the transfer function of the uplink and downlink beamforming network.

The amplitude and phase information {A _{C, n} , θ _{C, n} |n=1, 2, ..., N} of the signal vector r(t) input to the uplink beamforming network measured by the calibration network and the downlink beamforming measured by the receiving end The amplitude and phase information {A _{S, m} , θ _{S, m} |m=1, 2, ..., M} of the signal vector s(t) output by the network is used to obtain the M×N-dimensional transfer function matrix of the beamforming system.

To sum up, compared with the traditional test equipment vector network analyzer, the dedicated measurement solution for uplink and downlink beamforming based on the software radio method proposed by the present invention effectively reduces system complexity and test workload. According to the comparison results with the amplitude and phase parameters of the transfer matrix of the actual beamforming system, it can be seen that the transfer function matrix measured by the present invention can fully reflect the amplitude and phase characteristics of the uplink and downlink beamforming systems, thereby achieving lower measurement errors and achieving a higher High measurement accuracy.

The above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A measurement system for uplink and downlink beamforming, used to obtain the transfer matrix of a complete beamforming system based on software radio technology, one-time measurement, characterized in that, comprising: The transmitting end of the uplink beamforming system, the transmitting channel is simultaneously connected to the calibration channel of the amplitude-phase consistency calibration network of the transmitting channel and the receiving channel of the feed array of the uplink beamforming network; The sending channel amplitude-phase consistency calibration network adopts an online calibration mode; and At the receiving end of the downlink beamforming system, the receiving channel is connected to the transmitting channel of the feed array of the downlink beamforming network. 2. The uplink and downlink beamforming measurement system according to claim 1, characterized in that, The transmitting end of the uplink beamforming system adopts a field programmable gate array + digital-to-analog converter structure, and Both the transmitting channel amplitude-phase consistency calibration network and the receiving end of the downlink beamforming system adopt a structure of a field programmable gate array + an analog-to-digital converter. 3. The uplink and downlink beamforming measurement system according to claim 2, characterized in that, in the transmitting end of the uplink beamforming system, The field programmable gate array is used to control the amplitude of the beam sinusoidal signal to be transmitted in its transmission channel, and to adjust the phase of the beam sinusoidal signal by means of direct digital frequency synthesis, Wherein, the beam sinusoidal signal is processed to generate a test excitation signal, and the test excitation signal is sent to the uplink beamforming network. 4. The uplink and downlink beamforming measurement system according to claim 3, characterized in that, in the transmitting end of the uplink beamforming system, The test excitation signal is also fed into the sending channel amplitude-phase consistency calibration network through a power divider at the same time. 5. The uplink and downlink beamforming measurement system according to claim 2, wherein the transmission channel amplitude-phase consistency calibration network receives the uplink signal sent by the test system to the uplink beamforming system and transmits the feed through measurement The amplitude-phase inconsistency introduced by the power amplifier of the active device provides real-time amplitude-phase calibration for the transmitting end of the test system. 6. The uplink and downlink beamforming measurement system according to claim 2, wherein the receiving end of the downlink beamforming system is used to receive the downlink array element signal output by the downlink beamforming system and measure its amplitude-phase relationship . 7. A measurement method for uplink and downlink beamforming, used for using the uplink and downlink beamforming measurement system according to any one of the above claims, based on software radio technology, one-time measurement to obtain the transfer matrix of the complete beamforming system, characterized in that , including the following steps: Step 1: According to the preset angle of incidence of the beam signal relative to the uplink receiving antenna array, at the transmitting end of the uplink beamforming system, the signal processing method of field programmable gate array + digital-to-analog converter is used to configure the beam signal to be transmitted The amplitude-phase relationship of the sinusoidal signal in the channel; Step 2: In the amplitude-phase consistency calibration network of the transmission channel, the signal processing method of field programmable gate array + analog-to-digital converter is used to measure the relative amplitude-phase relationship of the sinusoidal signal in the calibration channel, which is used as the input feed of the uplink antenna array. The amplitude-phase relationship of the source signal; Step 3: At the receiving end of the downlink beamforming system, use the field programmable gate array + analog-to-digital converter signal processing method to receive and measure the amplitude-phase relationship of the sinusoidal signal in the receiving channel as the output feed source of the downlink antenna array the amplitude-phase relationship of the signal; and Step 4: According to the amplitude-phase relationship of the input feed signal of the uplink antenna array and the amplitude-phase relationship of the output feed signal of the downlink antenna array, calculate and obtain the transfer function played by the uplink and downlink beamforming, thereby obtaining a complete beamforming system the transfer matrix. 8. The uplink and downlink beamforming measurement method according to claim 7, further comprising: feeding back the relative amplitude-phase relationship of the feed signal measured by the transmission channel amplitude-phase consistency calibration network as the calibration amplitude-phase relationship to the transmitting end of the uplink beamforming system; and The transmitting end of the uplink beamforming system compares the calibration amplitude-phase relationship with the amplitude-phase relationship of the transmitted sinusoidal signal, and adjusts the amplitude and phase of the sinusoidal signal in the transmission channel in real time according to the error. 9. The uplink and downlink beamforming measurement method according to claim 7, characterized in that, in the step 2, comprising: The data acquisition of the received feed signal is realized through the analog-to-digital converter, and the intermediate frequency digital signal is obtained after sampling and quantization and input to the field programmable gate array; The field programmable gate array performs quadrature down-conversion processing on the intermediate frequency digital signal, so as to ensure that the relative phases of the input signals of each calibration channel in the transmission channel amplitude-phase consistency calibration network are not affected by the down-converter and ensure the two-way orthogonality of the output quadrature signal; and The root-raised cosine matched filter is used to perform root-raised cosine matched filter processing on the signal after quadrature down-conversion processing, so as to obtain the relative amplitude-phase relationship of each feed source signal. 10. The uplink and downlink beamforming measurement method according to claim 9, characterized in that, in the step 2, also comprising: The signal with the strongest power is used as a reference signal, and coherent cumulative average calculation is performed on the decision statistics output by the root raised cosine matched filter, so as to overcome the additive white Gaussian noise in the test process and obtain an accurate relative amplitude-phase relationship.