CN114499603A - A radio frequency link system based on digital switch matrix and its beamforming method - Google Patents

Abstract

The invention discloses a radio frequency link system based on a digital switch matrix and a beam forming method thereof, relating to the technical field of radar engineering, wherein the system comprises a radio frequency link system transmitting end and a radio frequency link system receiving end; the transmitting/receiving end of the radio frequency link system comprises Q₁/Q₂Digital signal forming device for transmitting/receiving end, signal processing module for transmitting/receiving end and P₁/P₂A transmitting/receiving antenna satisfying Q₁<P₁，Q₂<P₂. By introducing the digital switch matrix unit, the number of radio frequency link elements between the digital switch matrix unit of the transmitting/receiving end and the digital signal former of the transmitting/receiving end is far less than that of transmitting antennas/receiving antennas, so that the manufacturing cost and the running power consumption of the system are reduced; is provided withThe gating parameters of the digital switch matrix unit are set, so that the precision of the system is ensured; and the number of the input ends and the output ends of the digital switch matrix units keeps the degree of freedom, and the system performance requirements of different accuracies are met.

Description

A radio frequency link system based on digital switch matrix and its beamforming method

technical field

The invention relates to the technical field of radar engineering, and more particularly, to a radio frequency link system based on a digital switch matrix and a beam forming method thereof.

Background technique

With the large-scale application of 5G technology, there is a strong demand for ultra-high-speed data transmission in different scenarios, which greatly promotes the research and development of millimeter-wave communications. Millimeter wave communication has serious path loss and penetration loss, and needs to be combined with a Multiple-Input Multiple-Output (MIMO) system to provide sufficiently large beam gain and high-precision beam direction. Due to the strict restrictions on hardware manufacturing cost and system operating power, the hardware structure of traditional small-scale all-digital MIMO systems is difficult to implement in massive MIMO systems. Hybrid beamforming, as an alternative technology to all-digital beamforming, has become a solution to massive MIMO The main research direction of the problems faced by the system. In the field of radar, phased array radar is shining brightly, and it is widely used in almost all civil and military fields such as land-based and sea-based, and it is increasing; the general characteristics of phased array systems are large size and heavy weight. , The repeatability of the antenna is required to be high, the system integration is high, and the system reliability is required to be high. The main component in the active phased array system is the T/R component, whose cost usually accounts for 50% to 60% of the entire radar, and the rest is mainly the digital back-end processor. T/R components mainly include: local oscillator, up and down conversion, filter, power amplifier, low noise amplifier, phase shifter and attenuator. The T/R components and the digital-to-analog converter, the analog-to-digital converter, and the remaining modules of a single link are collectively referred to as a radio frequency link. With the increasing scale of phased arrays, more and more radio frequency links have become the main factor restricting the development of phased array systems. Learn from the related technologies of hybrid beamforming. At present, there are mainly two typical structures in hybrid beamforming, including a fully connected structure and a partially connected structure. In the fully-connected structure, under the condition that the RF link is reduced, in order to make full use of the beamforming degree of freedom provided by the RF link, the RF link is connected to each array element antenna, and the link formed by each RF and antenna is Both contain an analog phase shifter. Existing optimization algorithms can make full use of this structure to approximate the corresponding all-digital beamforming vectors, the most typical of which is the alternative iterative algorithm (MO-AltMin Algorithm) based on popular optimization. Compared with the fully connected structure and the fully digital structure, although the number of RF links has been greatly reduced, a huge number of analog phase shifters will be introduced into the system, especially when the number of antenna elements is large, not only the need for Major changes are made to the existing structure, and there will be precision problems caused by too many analog devices, making it difficult to implement engineering. In part of the connection structure, a radio frequency chain is connected to the fixed antenna sub-array, this structure can better reduce the cost of hardware manufacturing of massive MIMO and active phased array, but because the radio frequency chain is connected to the fixed antenna sub-array , so it is difficult for an RF link and its connected sub-array analog phase shifter to accurately replace the vector effect of multiple RF links in all-digital beamforming, and there is a greater performance loss. The more RF links are reduced, the more The more severe the performance penalty. In addition, most of the research on hybrid beamforming is aimed at maximizing spectrum utilization efficiency, while in the radar field it is mainly aimed at beamforming accuracy and system gain. To a certain extent, the algorithm developed by considering a certain performance index alone has application limitations, and the proposed solution cannot guarantee good performance for other performances, so the existing solutions cannot be effective. Balancing hardware cost and system performance requirements.

The prior art discloses a full-duplex active phased array antenna radio frequency link system and a method for determining a transceiver isolation. The radio frequency chain of the transmitting phased array system is composed of the transmitting antenna array, the receiving filter, the power amplifier, the phase shifter, a power divider, the driving power amplifier and a power divider; the radio frequency chain of the receiving phased array system It is composed of a routing receiving antenna array, a hair-resistance filter, a low-noise amplifier, a phase shifter, a one-in-one synthesizer, a driving low-noise amplifier, and a synthesizer. The scheme first extracts the voltage scattering vector, calculates the power coupled into the RF link of the receiving phased array system, and determines the isolation degree of the transmit-resistance filter. At the same time, the voltage reflection vector is extracted, the total thermal noise coupled from the RF link of the transmitting phased array system to the receiving antenna front is calculated, and the isolation degree of the receiving-rejection filter is determined. In the RF link system structure provided in the comparison document, in order to maintain the system performance requirements, each array element antenna corresponds to a RF link, and the number of RF links is huge, resulting in an increasing hardware cost and operating power consumption of the phased array system. high, which is not conducive to daily operation and maintenance.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned defects of the prior art that the hardware cost and system performance of the radio frequency link system cannot be effectively balanced, the present invention provides a radio frequency link system based on a digital switch matrix and a beam forming method thereof, which can meet the requirements of system performance accuracy. Under the premise, the manufacturing cost and operating power consumption of the system can be greatly reduced.

For solving the above-mentioned technical problems, the technical scheme of the present invention is as follows:

The invention provides a radio frequency link system based on a digital switch matrix, including a radio frequency link system transmitter and a radio frequency link system receiver;

The transmitting end of the radio frequency link system includes Q ₁ transmitting end digital signal formers, transmitting end signal processing modules and P ₁ transmitting antennas; the output ends of the Q ₁ transmitting end digital signal formers are respectively connected with the transmitting end signal processing module. The input end of the transmitter is connected to the input end of the transmitter signal processing module, and the output end of the transmitter signal processing module is respectively connected to the input end of the P ₁ transmit antennas, and the transmit antennas generate transmit signals;

The transmitter signal processing module includes several transmitter radio frequency link units and transmitter digital switch matrix units; each transmitter radio frequency link unit includes several series connected radio frequency link elements, and the radio frequency in each transmitter radio frequency link unit The connection sequence of the link elements is the same; the digital switch matrix unit of the transmitting end is arranged between any adjacent radio frequency link elements in the radio frequency link unit of the transmitting end, and the position in each radio frequency link unit of the transmitting end is the same;

The number of each type of radio frequency link elements between the output end of the digital signal former at the transmitting end and the input end of the digital switching matrix unit at the transmitting end is Q ₁ , the output end of the digital switching matrix unit at the transmitting end and the input of the transmitting antenna The number of each radio frequency link element between the terminals is P ₁ ;

The receiving end of the radio frequency link system includes P ₂ receiving antennas, a receiving end signal processing module and Q ₂ receiving end digital signal formers; P ₂ receiving antennas receive the transmitted signal, and the output ends of the P ₂ receiving antennas are The input ends of the receiving end signal processing module are connected, and the output ends of the receiving end signal processing module are respectively connected with the input ends of the Q ₂ receiving end digital signal formers, and the receiving end digital signal formers generate the final received signal;

The receiving end signal processing module includes several receiving end radio frequency link units and receiving end digital switch matrix units; each receiving end radio frequency link unit includes several serially connected radio frequency link elements, and the radio frequency in each receiving end radio frequency link unit is The connection sequence of the link elements is the same; the digital switch matrix unit of the receiving end is arranged between any adjacent radio frequency link elements in the radio frequency link unit of the receiving end, and the position in each radio frequency link unit of the receiving end is the same;

The number of each radio frequency link element between the output end of the receiving antenna and the input end of the receiving end digital switch matrix unit is P ₂ , the output end of the receiving end digital switch matrix unit and the input end of the receiving end digital signal former The number of each radio frequency link element between the terminals is Q ₂ ;

P ₁ , Q ₁ , P ₂ , and Q ₂ are all positive integers, and satisfy Q ₁ <P ₁ and Q ₂ <P ₂ .

In the existing fully connected structure, the radio frequency link needs to be connected to each array element antenna, and an analog phase shifter is included between each radio frequency link and the array element antenna, that is, the number of array element antennas is related to the radio frequency. The number of links is equal, the manufacturing cost and operating power consumption are high, and too many analog phase shifters will also reduce the system accuracy performance; in the existing part of the connection structure, one RF link is connected to the fixed antenna at the same time. Although the number of RF links is reduced, it is difficult for one RF link and its connected sub-array analog phase shifter to accurately replace the vector effect of multiple RF links, resulting in a large performance loss and the reduction of RF links. The more there are, the more serious the performance loss is; the present invention adds a digital switch matrix unit to the transmitter radio frequency link unit and the receiver radio frequency link unit, the transmitter/receiver digital switch matrix unit and the transmitter/receiver digital signal The number of radio frequency link elements between the formers is much smaller than the number of transmit/receive antennas, which greatly reduces the manufacturing cost and operating power consumption of the system. The RF link unit at the receiving end and the transmitting antenna/receiving antenna ensure the accuracy of the system; at the same time, the number of input ends and output ends of the digital switch matrix unit retains the degree of freedom to meet the system performance requirements of different precisions.

The present invention also provides a beamforming method for a radio frequency link system based on a digital switch matrix, including:

S1: The original signal is amplitude modulated by the transmitter digital signal former to output a digital signal;

S2: The digital signal is input to the signal processing module of the transmitting end. Several radio frequency link units of the transmitting end perform parameter processing on the digital signal to generate the transmitting signal; the digital switch matrix unit of the transmitting end selects the transmitting antenna to be connected, and outputs the transmitting signal to the transmission channel;

S3: The receiving antenna receives the transmitted signal in the transmission channel, and transmits it to the signal processing module of the receiving end;

S4: The receiving end digital switch matrix unit selects the receiving end radio frequency link unit that needs to be connected, and the received transmit signal is subjected to parameter processing by the receiving end radio frequency link unit to generate an initial received signal, and output to the receiving end digital signal former;

S5: The initial received signal is amplitude modulated by the digital signal former at the receiving end to generate the final received signal.

Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

The invention adds a digital switch matrix unit to the radio frequency link unit of the transmitting end and the radio frequency link unit of the receiving end, and the radio frequency link element between the digital switch matrix unit of the transmitting end/receiving end and the digital signal former of the transmitting end/receiving end The number is much smaller than the number of transmit/receive antennas, which greatly reduces the manufacturing cost and operating power consumption of the system; by setting the gating parameters of the digital switch matrix unit, select the transmitter/receiver RF link unit and transmit antenna that need to be connected /Receiving antenna, to ensure the accuracy of the system; at the same time, the number of input and output terminals of the digital switch matrix unit retains the degree of freedom to meet the system performance requirements of different precision.

Description of drawings

FIG. 1 is a schematic structural diagram of a radio frequency link system based on a digital switch matrix according to Embodiment 1. As shown in FIG.

FIG. 2 is a schematic structural diagram of a radio frequency link system based on a digital switch matrix according to Embodiment 2. As shown in FIG.

3 is a schematic structural diagram of the 23*12 digital switch matrix unit described in Embodiment 2;

4 is a schematic diagram of the relative error of the 64*64 square antenna array under the condition of no insertion loss described in Embodiment 2, when the number of radio frequency link units is 1, 6, 11, and 16;

5 is a schematic diagram of the relative error of the 64*64 square antenna array under the condition of no insertion loss described in Embodiment 2, and the number of radio frequency link units is 2, 7, 12, and 17;

6 is a schematic diagram of the relative error of the 64*64 square antenna array under the condition of no insertion loss described in Embodiment 2 and the number of radio frequency link units is 3, 8, 13, and 18;

7 is a schematic diagram of the relative error of the 64*64 square antenna array under the condition of no insertion loss described in Embodiment 2, and the number of radio frequency link units is 4, 9, 14, and 19;

FIG. 8 is a schematic diagram of the relative error of the 64*64 square antenna array under the condition of no insertion loss described in Embodiment 2, when the number of radio frequency link units is 5, 10, 15, and 20;

FIG. 9 is a schematic diagram of relative error amplification when the number of radio frequency link units is 12 under the condition of no insertion loss described in Embodiment 2 of the 64*64 square antenna array;

10 is a schematic diagram of relative error amplification when the number of radio frequency link units is 13 under the condition of no insertion loss of the 64*64 square antenna array described in Embodiment 2;

11 is a schematic diagram of relative error amplification when the number of radio frequency link units is 14 under the condition of no insertion loss of the 64*64 square antenna array described in Embodiment 2;

FIG. 12 is a schematic diagram of the relative error comparison when the number of radio frequency link units in the system in this embodiment is 13 and the number of radio frequency links in the fixed sub-array structure is 32 under the condition of no insertion loss described in Embodiment 2. ;

Figure 13 shows the 64*64 square antenna array under the condition of no insertion loss described in Embodiment 2. In this embodiment, the number of radio frequency link units in the system is 13, and when the number of radio frequency links in the fixed sub-array structure is 32, different signal-to-noise ratios A schematic diagram of the comparison of the spectral efficiency below;

Figure 14 shows the 64*64 square antenna array under the condition of no insertion loss described in Embodiment 2. In this embodiment, the number of radio frequency link units in the system is 13, and when the number of radio frequency links in the fixed sub-array structure is 32, different signal-to-noise ratios A partially enlarged schematic diagram of the spectral efficiency under;

15 is a schematic diagram of the relative error comparison when the number of radio frequency link units in the system in this embodiment is 16 and the number of radio frequency links in the fixed sub-array structure is 16 under the condition of no insertion loss described in Embodiment 2 ;

FIG. 16 shows the 64*64 square antenna array under the condition of no insertion loss described in Embodiment 2. In this embodiment, the number of radio frequency link units in the system is 16, and when the number of radio frequency links in the fixed sub-array structure is 16, different signal-to-noise ratios A schematic diagram of the comparison of the spectral efficiency below;

FIG. 17 shows the 64*64 square antenna array under the condition of no insertion loss described in Embodiment 2. In this embodiment, the number of radio frequency link units in the system is 16, and when the number of radio frequency links in the fixed sub-array structure is 16, different signal-to-noise ratios A partially enlarged schematic diagram of the spectral efficiency under;

FIG. 18 is a schematic diagram of the relative error of the 144*144 square antenna array under the condition of no insertion loss described in Embodiment 2, when the number of radio frequency link units is 1, 6, 11, and 16;

FIG. 19 is a schematic diagram of the relative error of the 144*144 square antenna array under the condition of no insertion loss described in Embodiment 2, when the number of radio frequency link units is 2, 7, 12, and 17;

FIG. 20 is a schematic diagram of the relative error of the 144*144 square antenna array under the condition of no insertion loss described in Embodiment 2, when the number of radio frequency link units is 3, 8, 13, and 18;

FIG. 21 is a schematic diagram of the relative error of the 144*144 square antenna array under the condition of no insertion loss described in Embodiment 2, when the number of radio frequency link units is 4, 9, 14, and 19;

FIG. 22 is a schematic diagram of the relative error of the 144*144 square antenna array under the condition of no insertion loss described in Embodiment 2, when the number of radio frequency link units is 5, 10, 15, and 20;

23 is a schematic diagram of relative error amplification when the number of radio frequency link units is 19 under the condition of no insertion loss described in Embodiment 2 of the 144*144 square antenna array;

FIG. 24 is a schematic diagram of the relative error amplification of the 144*144 square antenna array under the condition of no insertion loss described in Embodiment 2, when the number of radio frequency link units is 20 respectively;

FIG. 25 is a schematic diagram of the relative error amplification when the number of radio frequency link units is 21 in the 144*144 square antenna array under the condition of no insertion loss described in Embodiment 2;

26 is a schematic diagram of the relative error comparison when the number of radio frequency link units in the system in this embodiment is 21 and the number of radio frequency links in the fixed sub-array structure is 36 under the condition of no insertion loss described in Embodiment 2 ;

Figure 27 shows the 144*144 square antenna array under the condition of no insertion loss described in Embodiment 2. When the number of radio frequency link units in the system in this embodiment is 21, and the number of radio frequency links in the fixed sub-array structure is 36, different signal-to-noise ratios A schematic diagram of the comparison of the spectral efficiency below;

Figure 28 shows the 144*144 square antenna array under the condition of no insertion loss described in Embodiment 2. When the number of radio frequency link units in the system in this embodiment is 21, and the number of radio frequency links in the fixed sub-array structure is 36, different signal-to-noise ratios A partially enlarged schematic diagram of the spectral efficiency under;

FIG. 29 is a schematic diagram of the relative error comparison when the number of radio frequency link units in the system in this embodiment is 24 and the number of radio frequency links in the fixed sub-array structure is 24 under the condition of no insertion loss described in Embodiment 2. ;

Figure 30 shows the 144*144 square antenna array under the condition of no insertion loss described in Embodiment 2. When the number of radio frequency link units in the system in this embodiment is 24, and the number of radio frequency links in the fixed sub-array structure is 24, different signal-to-noise ratios A schematic diagram of the comparison of the spectral efficiency below;

Figure 31 shows the 144*144 square antenna array under the condition of no insertion loss described in Embodiment 2. When the number of radio frequency link units in the system in this embodiment is 24, and the number of radio frequency links in the fixed sub-array structure is 24, different signal-to-noise ratios A partially enlarged schematic diagram of the spectral efficiency under;

32 is a schematic structural diagram of a digital switch matrix-based radio frequency link system according to Embodiment 3;

FIG. 33 is a flowchart of a beamforming method for a digital switch matrix-based radio frequency link system according to Embodiment 4. FIG.

Detailed ways

The accompanying drawings are for illustrative purposes only, and should not be construed as limitations on this patent;

In order to better illustrate this embodiment, some parts of the drawings are omitted, enlarged or reduced, which do not represent the size of the actual product;

It will be understood by those skilled in the art that some well-known structures and their descriptions may be omitted from the drawings.

The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.

Example 1

This embodiment provides a radio frequency link system based on a digital switch matrix, as shown in FIG. 1 , including a transmitter end of the radio frequency link system and a receiver end of the radio frequency link system;

The transmitting end of the radio frequency link system includes Q ₁ transmitting end digital signal formers, transmitting end signal processing modules and P ₁ transmitting antennas; the output ends of the Q ₁ transmitting end digital signal formers are respectively connected with the transmitting end signal processing module. The input end of the transmitter is connected to the input end of the transmitter signal processing module, and the output end of the transmitter signal processing module is respectively connected to the input end of the P ₁ transmit antennas, and the transmit antennas generate transmit signals;

The transmitter signal processing module includes several transmitter radio frequency link units and transmitter digital switch matrix units; each transmitter radio frequency link unit includes several series connected radio frequency link elements, and the radio frequency in each transmitter radio frequency link unit The connection sequence of the link elements is the same; the digital switch matrix unit of the transmitting end is arranged between any adjacent radio frequency link elements in the radio frequency link unit of the transmitting end, and the position in each radio frequency link unit of the transmitting end is the same;

The number of each type of radio frequency link elements between the output end of the digital signal former at the transmitting end and the input end of the digital switching matrix unit at the transmitting end is Q ₁ , the output end of the digital switching matrix unit at the transmitting end and the input of the transmitting antenna The number of each radio frequency link element between the terminals is P ₁ ;

The receiving end of the radio frequency link system includes P ₂ receiving antennas, a receiving end signal processing module and Q ₂ receiving end digital signal formers; P ₂ receiving antennas receive the transmitted signal, and the output ends of the P ₂ receiving antennas are The input ends of the receiving end signal processing module are connected, and the output ends of the receiving end signal processing module are respectively connected with the input ends of the Q ₂ receiving end digital signal formers, and the receiving end digital signal formers generate the final received signal;

The receiving end signal processing module includes several receiving end radio frequency link units and receiving end digital switch matrix units; each receiving end radio frequency link unit includes several serially connected radio frequency link elements, and the radio frequency in each receiving end radio frequency link unit is The connection sequence of the link elements is the same; the digital switch matrix unit of the receiving end is arranged between any adjacent radio frequency link elements in the radio frequency link unit of the receiving end, and the position in each radio frequency link unit of the receiving end is the same;

The number of each radio frequency link element between the output end of the receiving antenna and the input end of the receiving end digital switch matrix unit is P ₂ , the output end of the receiving end digital switch matrix unit and the input end of the receiving end digital signal former The number of each radio frequency link element between the terminals is Q ₂ ;

P ₁ , Q ₁ , P ₂ , and Q ₂ are all positive integers, and satisfy Q ₁ <P ₁ and Q ₂ <P ₂ .

In the specific implementation process, the quantities of P ₁ and P ₂ are set according to actual requirements, which may be equal or unequal; the quantities of Q ₁ and Q ₂ are also set according to requirements, which may be equal or unequal; A digital switch matrix unit is added to the RF link unit at the end and the RF link unit at the receiving end. The number of RF link elements between the digital switch matrix unit at the transmitting end/receiving end and the digital signal former at the transmitting end/receiving end is much smaller than that of the transmitting antenna. The number of /receiving antennas greatly reduces the manufacturing cost and operating power consumption of the system; by setting the gating parameters of the digital switch matrix unit, select the radio frequency link unit and the transmitting antenna/receiving antenna that need to be connected. The accuracy of the system is improved; at the same time, the number of input terminals and output terminals of the digital switch matrix unit retains the degree of freedom to meet the system performance requirements of different precisions.

Example 2

This embodiment provides a radio frequency link system based on a digital switch matrix, including a radio frequency link system transmitter and a radio frequency link system receiver;

The transmitting end of the radio frequency link system includes Q ₁ transmitting end digital signal formers, transmitting end signal processing modules and P ₁ transmitting antennas; the output ends of the Q ₁ transmitting end digital signal formers are respectively connected with the transmitting end signal processing module. The input end of the transmitter is connected to the input end of the transmitter signal processing module, and the output end of the transmitter signal processing module is respectively connected to the input end of the P ₁ transmit antennas, and the transmit antennas generate transmit signals;

The transmitter signal processing module includes several transmitter radio frequency link units and transmitter digital switch matrix units; each transmitter radio frequency link unit includes several series connected radio frequency link elements, and the radio frequency in each transmitter radio frequency link unit The connection sequence of the link elements is the same; the digital switch matrix unit of the transmitting end is arranged between any adjacent radio frequency link elements in the radio frequency link unit of the transmitting end, and the position in each radio frequency link unit of the transmitting end is the same;

The number of each type of radio frequency link elements between the output end of the digital signal former at the transmitting end and the input end of the digital switching matrix unit at the transmitting end is Q ₁ , the output end of the digital switching matrix unit at the transmitting end and the input of the transmitting antenna The number of each radio frequency link element between the terminals is P ₁ ;

The receiving end of the radio frequency link system includes P ₂ receiving antennas, a receiving end signal processing module and Q ₂ receiving end digital signal formers; P ₂ receiving antennas receive the transmitted signal, and the output ends of the P ₂ receiving antennas are The input ends of the receiving end signal processing module are connected, and the output ends of the receiving end signal processing module are respectively connected with the input ends of the Q ₂ receiving end digital signal formers, and the receiving end digital signal formers generate the final received signal;

The receiving end signal processing module includes several receiving end radio frequency link units and receiving end digital switch matrix units; each receiving end radio frequency link unit includes several serially connected radio frequency link elements, and the radio frequency in each receiving end radio frequency link unit is The connection sequence of the link elements is the same; the digital switch matrix unit of the receiving end is arranged between any adjacent radio frequency link elements in the radio frequency link unit of the receiving end, and the position in each radio frequency link unit of the receiving end is the same;

The number of each radio frequency link element between the output end of the receiving antenna and the input end of the receiving end digital switch matrix unit is P ₂ , the output end of the receiving end digital switch matrix unit and the input end of the receiving end digital signal former The number of each radio frequency link element between the terminals is Q ₂ ;

P ₁ , Q ₁ , P ₂ , and Q ₂ are all positive integers, and satisfy Q ₁ <P ₁ and Q ₂ <P ₂ .

The several series-connected radio frequency link elements in each transmitting end radio frequency link unit include a digital-to-analog converter, a first mixer, a power amplifier and a first phase shifter; the connection sequence is the digital-to-analog converter, the first mixer The frequency converter, the power amplifier and the first phase shifter are connected in sequence; the input end of the digital-to-analog converter is used as the input end of the transmitting end signal processing module to be connected with the output ends of the Q ₁ transmitting end digital signal formers, and the first phase shifter The output end of 1 is connected with the input end of P ₁ transmitting antennas as the output end of the signal processing module of the transmitting end.

The several series-connected radio frequency link elements in each receiving end radio frequency link unit include a second phase shifter, a low noise amplifier, a second frequency mixer and an analog-to-digital converter; the connection sequence is the second phase shifter, the low The noise amplifier, the second mixer and the analog-to-digital converter are connected in sequence; the input end of the second phase shifter is used as the input end of the receiving end signal processing module to be connected with the output ends of the P ₂ receiving antennas, and the output end of the analog-to-digital converter is connected. As the output end of the signal processing module of the receiving end, the end is connected to the input ends of the Q ₂ receiving end digital signal formers respectively.

The first phase shifter is a high power phase shifter.

The second phase shifter is a low power phase shifter.

The radio frequency link elements in each of the radio frequency link unit at the transmitting end and the radio frequency link unit at the receiving end further include a local oscillator;

In each transmitter-side RF link unit or receiver-side RF link unit, the local oscillator is connected to the first mixer or the second mixer, and the local oscillator generates an oscillating signal and injects it into the first mixer or second mixer.

经过接收端数字开关矩阵单元选择连通所需连通的接收端射频链路单元，将其传输至低噪声放大器和接入本机振荡器的第二混频器进行降噪和频率调制，通过模数转换器将模拟信号转换成数字信号格式的初始接收信号，最后由接收端数字信号形成器进行幅度调制，输出最终接收信号

在本实施例中，发射端数字开关矩阵单元与发射端数字信号形成器之间的数模转换器、第一混频器、本机振荡器、功率放大器的数量均为Q₁个，发射端数字开关矩阵单元与发射天线之间的第一移相器的数量为P₁个；接收端数字开关矩阵单元与接收天线之间的第二移相器的数量为P₂个，接收端数字开关矩阵单元与发射端数字信号形成器之间的低噪声放大器、第二混频器、本机振荡器、模数转换器的数量均为Q₂个；Q₁的值远小于P₁的值，Q₂的值远小于P₂的值，本实施例大大降低了系统的制造成本和运行功耗，同时，数字开关矩阵单元的输入端和输出端的数量保留自由度，以满足不同精度的系统性能要求。As shown in Figure 2, taking the example of connecting the digital switch matrix unit at the transmitting end between the power amplifier and the first phase shifter, and connecting the digital switching matrix unit at the receiving end between the second phase shifter and the low noise amplifier, The original signal X is input to the transmitting end of the radio frequency link system, and the digital signal former at the transmitting end performs amplitude modulation on the original signal X to generate a digital signal F _BB X; the function of the digital-to-analog converter is to convert the digital signal F _BB X into an analog signal, By adding the first mixer and power amplifier of the local oscillator, it is converted to the corresponding high frequency and power level, and the transmitting antenna that needs to be connected is selected through the digital switch matrix unit of the transmitting end, and finally the phase is carried out through the high-power phase shifter. Modulated to form a transmit signal F _RF F _BB X and transmitted to the transmission channel through the transmit antenna. The transmission channel matrix is denoted as H, then the transmitted signal propagated in the transmission channel is HF _RF F _BB X; the signal received by the receiving antenna includes the transmitted signal and noise HF _RF F _BB X+n propagated in the transmission channel. The phase shifter performs phase modulation, and the output

The receiver RF link unit that needs to be connected is selected through the receiver digital switch matrix unit, and transmitted to the low noise amplifier and the second mixer connected to the local oscillator for noise reduction and frequency modulation. The converter converts the analog signal into the initial received signal in the digital signal format, and finally performs amplitude modulation by the digital signal former at the receiving end to output the final received signal

In this embodiment, the number of digital-to-analog converters, _first mixers, local oscillators, and power amplifiers between the transmitter digital switch matrix unit and the transmitter digital signal former is Q1, and the transmitter The number of first phase shifters between the digital switch matrix unit and the transmitting antenna is P ₁ ; the number of second phase shifters between the digital switch matrix unit at the receiving end and the receiving antenna is P ₂ , and the digital switch at the receiving end The number of low-noise amplifiers, second mixers, local oscillators, and analog-to-digital converters between the matrix unit and the digital signal former at the transmitting end is Q ₂ ; the value of Q ₁ is much smaller than the value of P ₁ , The value of _Q2 is much smaller _than the value of P2. This embodiment greatly reduces the manufacturing cost and operating power consumption of the system. At the same time, the number of input terminals and output terminals of the digital switch matrix unit retains the degree of freedom to meet the system performance of different precisions. Require.

As shown in Figure 3, it is a schematic diagram of the structure of a 23*12 digital switch matrix unit. In actual industrial production, the digital switch matrix unit manufactured by high-performance relays can achieve the performance indicators in the following table:

Frequency (MHz) Insertion loss (dB) 500 <0.3 2500 <0.7 4000 <1.0 8000 <1.5 10000 <2.0

For the insertion loss of the digital switch matrix unit at different frequencies, the corresponding amplitude compensation coefficient and power compensation coefficient can be obtained from the following table:

Frequency (MHz) Insertion loss (dB) Amplitude loss Amplitude compensation coefficient Power compensation factor 500 0.3 0.9661 1.0351 1.0714 2500 0.7 0.9226 1.0839 1.1748 4000 1.0 0.8913 1.1220 1.2588 8000 1.5 0.8414 1.1885 1.4125 10000 2.0 0.7943 1.2590 1.5850

Amplitude compensation coefficient: Under the condition of insertion loss caused by different frequencies, increasing the voltage (amplitude) value several times of the amplitude compensation coefficient can offset the performance loss caused by the introduction of digital switch matrix in the system.

Power compensation coefficient: Under the condition of insertion loss caused by different frequencies, increasing the power value of the power compensation coefficient several times can offset the performance loss caused by the introduction of digital switch matrix in the system.

Set up experiments to verify the performance of a digital switch matrix-based radio frequency link system provided in this embodiment. Two scenarios are set up, one scenario is 64 transmit antennas and 64 receive antennas, that is, a 64*64 square antenna array; the other The scene is 144 transmitting antennas and 144 receiving antennas, that is, a 128*128 square antenna array, that is, setting P ₁ =P ₂ , Q ₁ =Q ₂ , in the illustration of the experimental results, Q ₁ and Q ₂ are denoted as Q; By performing singular value decomposition on the channel matrix modeled by the Saleh-Valenzuela (SV) channel model, the optimal transmit all-digital beamforming vector F _opt and the optimal receive all-digital beamforming vector W _opt are obtained, where the scattering clusters of the channel The number is 5, and each scattering cluster contains 10 propagation paths; 1000 Monte Carlo experiments are performed for each experimental scene to obtain the average result, and the spectrum of the all-digital structure, the fixed sub-array structure and the system provided in this embodiment are compared. Efficiency and the relative error of the modulo value of the optimal transmitting all-digital beamforming vector F _opt and the beamforming vector F _pcs obtained in this embodiment; the specific steps are:

ST1: Perform singular value decomposition on the channel matrix H: H=U∑V ^H , the first column of the V, U matrix is the optimal transmitting all-digital beamforming vector F _opt and the optimal receiving all-digital beamforming vector W _opt ;

ST2: Extract the phase information of the target vector, assign its phase value to the phase shifter, and obtain the transmit analog beamforming vector F _RF ;

ST3: Obtain the maximum value M and the minimum value m of the amplitude of the optimal transmit all-digital beamforming vector F _opt ;

ST4: According to the interval [m, M], group the number of radio frequency link units to obtain grouped sub-intervals, and group the amplitude values of all target vectors according to the grouped sub-intervals to generate switch data of the digital switch matrix unit;

即得到发射数字波束形成矢量F_BB；i表示分组子区间内有i个目标矢量幅度值；ST5: Select the optimal amplitude value in each grouping sub-interval to approximate replacement of all amplitude values in the grouping sub-interval, and the optimal amplitude value is

That is, the transmitting digital beamforming vector F _BB is obtained; i represents that there are i target vector magnitude values in the grouping sub-interval;

Steps ST1-ST5 are repeated to obtain the receiving digital beamforming vector _WBB and the receiving analog beamforming vector _WRF ;

ST6: Calculate the spectral efficiency of the all-digital structure, the calculation formula is:

ST7: Calculate the spectral efficiency of the system provided by this embodiment, and the calculation formula is:

ST8: Calculate the relative error of the modulo value of the optimal transmit all-digital beamforming vector F _opt and the beamforming vector F _pcs obtained in this embodiment. The calculation method is as follows:

原始信号满足Ε[XX^H]＝1；In the formula, ε represents the relative error, ρ represents the transmit power, and the noise n is an independent and identically distributed Gaussian noise with a mean of 0 and a variance of

The original signal satisfies E[XX ^H ]=1;

As shown in Figure 4, it is a schematic diagram of the relative error of a 64*64 square antenna array under the condition of no insertion loss, and the number of RF link units is 1, 6, 11, and 16; as shown in Figure 5, under the condition of no insertion loss 64*64 square antenna array, relative error diagram when the number of RF link units is 2, 7, 12, 17; as shown in Figure 6, it is a 64*64 square antenna array under the condition of no insertion loss, the number of RF link units Schematic diagram of relative error when 3, 8, 13, and 18 are shown; as shown in Figure 7, it is a 64*64 square antenna array under the condition of no insertion loss, and the relative error when the number of RF link units is 4, 9, 14, and 19 Schematic diagram; as shown in Figure 8, it is a schematic diagram of the relative error when the number of RF link units is 5, 10, 15, and 20 under the condition of no insertion loss for a 64*64 square antenna array; as shown in Figure 9-11, it is no A schematic diagram of relative error amplification when the number of RF link units is 12, 13, and 14 for a 64*64 square antenna array under the condition of insertion loss. In Figure 4-8, the relative error when the number of RF link units is 1-20 is compared. It can be seen from the figure that as the number of RF link units increases, the relative error becomes smaller and smaller. From Figure 9-11 It can be seen from the figure that the magnitude of the drop is also gradually reduced; therefore, the minimum number of RF link units should be selected as the final result under the premise of meeting the system performance requirements. As shown in Figure 12, it is a 64*64 square antenna array under the condition of no insertion loss, the number of radio frequency link units in this embodiment is 13, and the number of radio frequency links in the fixed sub-array structure is 32, the relative error comparison diagram; from It can be seen from the figure that the relative error of the fixed sub-array structure is about 5 times that of the system provided by this embodiment; as shown in Figure 13, it is a 64*64 square antenna array under the condition of no insertion loss, this embodiment When the number of RF link units in the system is 13 and the number of RF links in the fixed sub-array structure is 32, the comparison diagram of the spectral efficiency under different signal-to-noise ratios; as shown in Figure 14, it is a 64*64 square under the condition of no insertion loss Antenna array, when the number of radio frequency link units in the system in this embodiment is 13, and the number of radio frequency links in the fixed sub-array structure is 32, the partial enlarged schematic diagram of the spectral efficiency under different signal-to-noise ratios; it can be seen from Figure 13-14 , the spectral efficiency of the system provided by this embodiment is basically the same as that of the full number, while the spectral efficiency of the fixed sub-array structure is poor; as shown in Figure 15, it is a 64*64 square antenna array under the condition of no insertion loss. When the number of radio frequency link units in the system is 16, and the number of radio frequency links in the fixed sub-array structure is 16, the relative error comparison diagram; it can be seen from the figure that the relative error of the fixed sub-array structure is the relative error of the system provided in this embodiment. The error is about 10 times of the error; as shown in Figure 16, it is a 64*64 square antenna array under the condition of no insertion loss. A schematic diagram of the comparison of spectral efficiency under different signal-to-noise ratios; as shown in Figure 17, it is a 64*64 square antenna array under the condition of no insertion loss. When the number of channels is 16, the partial enlarged schematic diagram of the spectral efficiency under different signal-to-noise ratios; it can be seen from Figures 16-17 that the spectral efficiency of the system provided by this embodiment is basically the same as the full number, and the fixed sub-array structure The spectral efficiency is poor.

As shown in Figure 18, it is a schematic diagram of the relative error of a 144*144 square antenna array under the condition of no insertion loss, and the number of RF link units is 1, 6, 11, and 16; as shown in Figure 19, it is under the condition of no insertion loss 144*144 square antenna array, relative error diagram when the number of RF link units is 2, 7, 12, 17; as shown in Figure 20, it is a 144*144 square antenna array under the condition of no insertion loss, the number of RF link units Schematic diagram of relative errors when 3, 8, 13, and 18 are shown; as shown in Figure 21, it is a 144*144 square antenna array under the condition of no insertion loss, and the relative errors when the number of RF link units is 4, 9, 14, and 19 Schematic diagram; as shown in Figure 22, it is a schematic diagram of the relative error when the number of RF link units is 5, 10, 15, and 20 under the condition of no insertion loss 144*144 square antenna array; as shown in Figure 23-25, it is no A schematic diagram of the relative error amplification when the number of RF link units is 19, 20, and 21 for a 144*144 square antenna array under the condition of insertion loss. In Figure 18-22, the relative error when the number of RF link units is 1-20 is compared. It can be seen from the figure that as the number of RF link units increases, the relative error becomes smaller and smaller. From Figure 23-25 It can be seen from the figure that the magnitude of the drop is also gradually reduced; therefore, the minimum number of RF link units should be selected as the final result under the premise of meeting the system performance requirements. As shown in Figure 26, it is a 144*144 square antenna array under the condition of no insertion loss. The number of radio frequency link units in this embodiment is 21, and the number of radio frequency links in the fixed sub-array structure is 36. The relative error comparison diagram; from It can be seen from the figure that the relative error of the fixed sub-array structure is about 7 times that of the system provided by this embodiment; as shown in Figure 27, it is a 144*144 square antenna array under the condition of no insertion loss, this embodiment When the number of RF link units in the system is 21 and the number of RF links in the fixed sub-array structure is 36, the comparison diagram of the spectral efficiency under different signal-to-noise ratios; as shown in Figure 28, it is a 144*144 square under the condition of no insertion loss Antenna array, when the number of radio frequency link units in the system in this embodiment is 21, and the number of radio frequency links in the fixed sub-array structure is 36, the partial enlarged schematic diagram of the spectral efficiency under different signal-to-noise ratios; it can be seen from Figures 27-28 , the spectral efficiency of the system provided by this embodiment is basically the same as that of all digital, while the spectral efficiency of the fixed sub-array structure is poor; as shown in Figure 29, it is a 144*144 square antenna array under the condition of no insertion loss. When the number of radio frequency link units in the system is 24, and the number of radio frequency links in the fixed sub-array structure is 24, the relative error comparison diagram; it can be seen from the figure that the relative error of the fixed sub-array structure is the relative error of the system provided in this embodiment. The error is about 10 times of the error; as shown in Figure 30, it is a 144*144 square antenna array under the condition of no insertion loss. Schematic diagram of the comparison of spectral efficiency under different signal-to-noise ratios; as shown in Figure 31, it is a 144*144 square antenna array under the condition of no insertion loss, the number of radio frequency link units in this embodiment is 24, and the radio frequency chain of fixed sub-array structure is When the number of channels is 24, the partially enlarged schematic diagram of the spectral efficiency under different signal-to-noise ratios; it can be seen from Figures 30-31 that the spectral efficiency of the system provided by this embodiment is basically the same as that of the full number, and the fixed sub-array structure The spectral efficiency is poor. Moreover, it can be seen from Figures 12, 15, 26, and 29 that when the number of radio frequency links in the two structures is the same or when the number of frequency links in the fixed sub-array structure is larger, the relative errors are higher than those of the system provided in this embodiment. The relative error is 5-10 times larger.

In the experimental results, the result where the average relative error of the modulo value of the optimal transmitting all-digital beamforming vector F _opt and the beamforming vector F _pcs obtained in this embodiment is lower than 0.05 (which can be selected according to the actual system performance requirements) is selected as the most The best approximate solution. It can be seen from the experimental results that for a 64*64 square antenna array, the minimum number of RF link units to achieve an approximately optimal beamforming vector is 13; for a 144*144 square antenna array, an approximately optimal beamforming vector is achieved. The minimum number of RF link elements to form a vector is 21. When the insertion loss caused by the digital switch matrix unit is not considered, for a 64*64 square antenna array, the number of RF link units in this embodiment is 13, and when the number of RF links in a traditional fixed sub-array is 32, all digital The spectrum utilization efficiency of the structure is 6.2992 (bits/s/Hz) at -12.5dB, the spectrum utilization efficiency of this embodiment is 6.29526 (bits/s/Hz), and the spectrum utilization efficiency of the fixed sub-array structure is 6.17973 (bits/ s/Hz), even if 19 additional radio frequency links are added under the traditional structure, the spectral efficiency is still lower than that of the system provided in this embodiment. For a 64*64 square antenna array, the system provided by this embodiment reduces the number of radio frequency links by 79.7% compared to the all-digital structure. When the insertion loss caused by the digital switch matrix unit is not considered, the 144*144 square antenna array, the number of RF link units in this embodiment is 21, and the number of RF links in the traditional fixed sub-array structure is 36, all digital The spectrum utilization efficiency of the structure is 8.27943 (bits/s/Hz) at -12.5dB, the spectrum utilization efficiency of this embodiment is 8.27785 (bits/s/Hz), and the spectrum utilization efficiency of the fixed sub-array structure is 8.0948 (bits/ s/Hz), even if 15 additional radio frequency links are added under the traditional structure, the spectral efficiency is still lower than that of the system provided in this embodiment. For a 144*144 square antenna array, the system provided by this embodiment reduces the number of radio frequency links by 85.4% compared to the full digital structure.

In this embodiment, by adding a digital switch matrix unit, the number of radio frequency link elements between the digital switch matrix unit at the transmitting end/receiving end and the digital signal former at the transmitting end/receiving end is much smaller than the number of transmitting antennas/receiving antennas, which greatly reduces the number of radio frequency link elements. The manufacturing cost and operating power consumption of the system are reduced, but the performance index of the power amplifier needs to be increased, and the phase shifter also needs a higher power tolerance; the approximate replacement of the optimal target vector is directly performed. The requirements are universal; at the same time, the number of input and output terminals of the digital switch matrix unit retains the degree of freedom to meet the system performance requirements of different precisions.

Example 3

This embodiment provides a radio frequency link system based on a digital switch matrix, as shown in Figure 32; compared with Embodiment 2, the differences are:

The several series-connected radio frequency link elements in each transmitting end radio frequency link unit include a digital-to-analog converter, a first mixer, a power amplifier and a first phase shifter; the connection sequence is the digital-to-analog converter, the first mixer The frequency converter, the first phase shifter and the power amplifier are connected in sequence; the input end of the digital-to-analog converter is used as the input end of the transmitting end signal processing module to be connected with the output ends of the Q ₁ transmitting end digital signal formers, and the output end of the power amplifier is connected. The output end of the signal processing module as the transmitting end is connected to the input ends of the P ₁ transmitting antennas.

The several series-connected radio frequency link elements in each receiving end radio frequency link unit include a second phase shifter, a low noise amplifier, a second mixer and an analog-to-digital converter; the connection sequence is the low noise amplifier, the second shifter The phaser, the second mixer and the analog-to-digital converter are connected in sequence; the input end of the low-noise amplifier is used as the input end of the receiving end signal processing module to be connected with the output ends of the P ₂ receiving antennas, and the output end of the analog-to-digital converter is used as the input end of the receiver antenna. The output ends of the receiving end signal processing module are respectively connected with the input ends of the Q ₂ receiving end digital signal formers.

The first phase shifter and the second phase shifter are both low power phase shifters.

In this embodiment, by adding a digital switch matrix unit, the number of radio frequency link elements between the digital switch matrix unit at the transmitting end/receiving end and the digital signal former at the transmitting end/receiving end is much smaller than the number of transmitting antennas/receiving antennas, which greatly reduces the number of radio frequency link elements. The manufacturing cost and operating power consumption of the system are reduced; although the number of reduced RF link elements is smaller than that in Example 2, the insertion loss of the digital switch matrix unit is smaller under low frequency conditions, and the remaining RF link elements No major changes are required, which is beneficial to the transformation of the existing MIMO system and phased array system, and the method multiple of the power amplifier is also smaller than that of the power amplifier in Embodiment 2. The approximate replacement of the optimal target vector is directly applicable to different system performance requirements; at the same time, the number of input and output terminals of the digital switch matrix unit retains the degree of freedom to meet the system performance requirements of different precisions.

Example 4

This embodiment provides a beamforming method for a radio frequency link system based on a digital switch matrix, as shown in FIG. 33 , including:

S1: The original signal is amplitude modulated by the transmitter digital signal former to output a digital signal;

S2: The digital signal is input to the signal processing module of the transmitting end, and several radio frequency link units of the transmitting end perform parameter processing on the digital signal to generate the transmitting signal; the digital switching matrix unit of the transmitting end selects the transmitting antenna that needs to be connected, and outputs the transmitting signal to the transmission channel;

S3: The receiving antenna receives the transmitted signal in the transmission channel, and transmits it to the signal processing module of the receiving end;

S4: The receiving end digital switch matrix unit selects the receiving end radio frequency link unit that needs to be connected, and the received transmit signal is subjected to parameter processing by the receiving end radio frequency link unit to generate an initial received signal, and output to the receiving end digital signal former;

S5: The initial received signal is amplitude modulated by the digital signal former at the receiving end to generate the final received signal.

The same or similar reference numbers correspond to the same or similar parts;

The terms describing the positional relationship in the accompanying drawings are only used for exemplary illustration, and should not be construed as a limitation on this patent;

Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims (10)

1. A radio frequency link system based on a digital switch matrix is characterized by comprising a radio frequency link system transmitting end and a radio frequency link system receiving end;

the transmitting end of the radio frequency link system comprises Q₁Digital signal form of individual transmitting terminalSynthesizer, transmitting end signal processing module and P₁A plurality of transmitting antennas; q₁The output end of the transmitter digital signal former is respectively connected with the input end of the transmitter signal processing module, and the output end of the transmitter signal processing module is respectively connected with the P₁The input ends of the transmitting antennas are connected, and the transmitting antennas generate transmitting signals;

the transmitting end signal processing module comprises a plurality of transmitting end radio frequency link units and transmitting end digital switch matrix units; each transmitting end radio frequency link unit comprises a plurality of radio frequency link elements which are connected in series, and the connection sequence of the radio frequency link elements in each transmitting end radio frequency link unit is the same; the transmitting end digital switch matrix unit is arranged between any adjacent radio frequency link elements in the transmitting end radio frequency link unit, and the positions in each transmitting end radio frequency link unit are the same;

the number of each radio frequency link element between the output end of the transmitting end digital signal former and the input end of the transmitting end digital switch matrix unit is Q₁The number of each radio frequency link element between the output end of the transmitting end digital switch matrix unit and the input end of the transmitting antenna is P₁A plurality of;

the receiving end of the radio frequency link system comprises P₂Receiving antenna, receiving end signal processing module and Q₂A receiving end digital signal former; p₂A receiving antenna for receiving the transmitted signal, P₂The output end of each receiving antenna is respectively connected with the input end of a receiving end signal processing module, and the output end of the receiving end signal processing module is respectively connected with the Q₂The input end of each receiving end digital signal former is connected with the other receiving end digital signal former, and the receiving end digital signal former generates a final receiving signal;

the receiving end signal processing module comprises a plurality of receiving end radio frequency link units and receiving end digital switch matrix units; each receiving end radio frequency link unit comprises a plurality of radio frequency link elements which are connected in series, and the connection sequence of the radio frequency link elements in each receiving end radio frequency link unit is the same; the receiving end digital switch matrix unit is arranged between any adjacent radio frequency link elements in the receiving end radio frequency link unit, and the positions in each receiving end radio frequency link unit are the same;

the number of each radio frequency link element between the output end of the receiving antenna and the input end of the receiving end digital switch matrix unit is P₂The number of each radio frequency link element between the output end of the receiving end digital switch matrix unit and the input end of the receiving end digital signal former is Q₂A plurality of;

P₁、Q₁、P₂、Q₂are all positive integers satisfying Q₁<P₁，Q₂<P₂。

2. The digital switch matrix based radio frequency link system of claim 1, wherein the plurality of series connected radio frequency link elements in each transmitting end radio frequency link unit comprises a digital-to-analog converter, a first mixer, a power amplifier and a first phase shifter; the connection sequence is that the digital-to-analog converter, the first mixer, the power amplifier and the first phase shifter are connected in sequence; the input end of the digital-to-analog converter is used as the input end of the transmitting end signal processing module and Q₁The output end of the transmitter digital signal former is connected with the output end of the first phase shifter as the output end of the transmitter signal processing module and P₁The input ends of the transmitting antennas are connected.

3. The digital switch matrix based rf link system of claim 1, wherein the plurality of rf link elements connected in series in each receiving-side rf link unit comprises a second phase shifter, a low noise amplifier, a second mixer, and an analog-to-digital converter; the second phase shifter, the low noise amplifier, the second frequency mixer and the analog-to-digital converter are connected in sequence; the input end of the second phase shifter is used as the input end of the receiving end signal processing module and P₂The output end of each receiving antenna is connected with the output end of the analog-to-digital converter, and the output ends of the analog-to-digital converters are used as the output ends of the receiving end signal processing modules and are respectively connected with the Q₂The input ends of the receiving end digital signal generators are connected.

4. The digital switch matrix based rf link system of claim 2, wherein the first phase shifter is a high power phase shifter.

5. The digital switch matrix based radio frequency link system of claim 3, wherein the second phase shifter is a low power phase shifter.

6. The digital switch matrix-based radio frequency link system of claim 2 or 3, wherein the radio frequency link elements in each of the transmitting side radio frequency link units and the receiving side radio frequency link units further comprise a local oscillator;

in each transmitting end radio frequency link unit or receiving end radio frequency link unit, a local oscillator is connected with a first mixer or a second mixer, and the local oscillator generates an oscillating signal to be injected into the first mixer or the second mixer.

7. The digital switch matrix based radio frequency link system of claim 1, wherein the plurality of series connected radio frequency link elements in each transmitting end radio frequency link unit comprises a digital-to-analog converter, a first mixer, a power amplifier and a first phase shifter; the connection sequence is that the digital-to-analog converter, the first mixer, the first phase shifter and the power amplifier are connected in sequence; the input end of the digital-to-analog converter is used as the input end of the transmitting end signal processing module and Q₁The output end of the digital signal former of the transmitting end is connected, and the output end of the power amplifier is used as the output end of the signal processing module of the transmitting end and is connected with the P₁The input ends of the transmitting antennas are connected.

8. The digital switch matrix based rf link system of claim 1, wherein the plurality of rf link elements connected in series in each receiving-side rf link unit comprises a second phase shifter, a low noise amplifier, a second mixer, and an analog-to-digital converter; the low noise amplifier, the second phase shifter, the second frequency mixer and the analog-to-digital converter are connected in sequence;the input end of the low noise amplifier is used as the input end of the receiving end signal processing module and P₂The output end of each receiving antenna is connected with the output end of the analog-to-digital converter, and the output ends of the analog-to-digital converters are used as the output ends of the receiving end signal processing modules and are respectively connected with the Q₂The input ends of the receiving end digital signal generators are connected.

9. The digital switch matrix based radio frequency link system according to claim 7 or 8, wherein the first phase shifter and the second phase shifter are both low power phase shifters.

10. A method for beamforming in a radio frequency link system based on a digital switch matrix, comprising:

s1: the original signal is subjected to amplitude modulation by a transmitting terminal digital signal generator, and a digital signal is output;

s2: the digital signals are input into a transmitting end signal processing module, and a plurality of transmitting end radio frequency link units carry out parameter processing on the digital signals to generate transmitting signals; the transmitting terminal digital switch matrix unit selects transmitting antennas to be communicated and outputs transmitting signals to a transmission channel through the transmitting antennas;

s3: the receiving antenna receives the transmitting signal in the transmission channel and transmits the transmitting signal to the receiving end signal processing module;

s4: the receiving end digital switch matrix unit selects a receiving end radio frequency link unit which needs to be communicated, and the received transmitting signal is subjected to parameter processing by the receiving end radio frequency link unit to generate an initial receiving signal and is output to a receiving end digital signal former;

s5: the initial receiving signal is amplitude modulated by the receiving end digital signal former to generate the final receiving signal.

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