CN-121995342-A - Software defined Lei Daquan link integrated signal processing method

Abstract

The invention discloses a software defined Lei Daquan link integrated signal processing method, and belongs to the technical field of radar signal processing. The method constructs a layered decoupling general hardware platform consisting of an AD9361 general radio frequency front end, a high-speed data transmission interface and an FPGA+GPU+CPU heterogeneous computing rear end, and realizes the software definition of full-link functions such as waveform generation, signal processing, synchronous control and the like. The invention adopts a double self-adaptive CFAR detection algorithm of 'distance dynamic window and clutter multi-algorithm switching', can adapt to all clutter environments, realizes nanosecond coherent synchronization of multiple radar nodes through a GPS tame clock, ensures UTC synchronization accuracy to be +/-50 ns, and realizes multi-station MIMO collaborative detection through software wave beam formation. The invention increases the instantaneous bandwidth of the radar from 5MHz to 56MHz, reduces the signal processing delay from 6.8 mu s to 1.2 mu s, reduces the false alarm rate from 10-3 to 10-6, shortens the research and development period from 18-24 months to 6-12 months, and reduces the hardware cost to 1/5-1/10 of the traditional scheme.

Inventors

• HE XIANGYU
• CHEN ZHENGNAN
• LI HAOMIN
• ZHANG SHUO

Assignees

• 何祥宇
• 广东空天抗扰技术研究院有限公司

Dates

Publication Date

20260508

Application Date

20260408

Claims (10)

1. 1. The software defined Lei Daquan link integrated signal processing method is characterized by comprising the following steps: a. Constructing a layered decoupling general hardware platform consisting of an AD9361 general radio frequency front end, a high-speed data transmission interface and an FPGA+GPU+CPU heterogeneous computation rear end; b. Directly generating baseband I/Q waveform data through a software algorithm, and realizing full-parameter configurable software waveform definition and waveform agility less than or equal to 10 ms; c. The method comprises the steps of realizing full-software self-adaptive signal processing of pulse compression, moving target detection and constant false alarm detection on a general computing platform, wherein the constant false alarm detection adopts a double self-adaptive mode of combining a distance dynamic window and clutter multi-algorithm switching; d. A GPS tame clock is adopted to realize nanosecond coherent synchronization of multiple radar nodes, and UTC synchronization precision can reach +/-50 ns; e. and realizing multi-station MIMO collaborative detection through software beam forming.
2. 2. The method of claim 1, wherein the AD9361 universal radio frequency front-end covers a 70MHz-6GHz continuous band, with an instantaneous bandwidth up to 56MHz, supporting a 2T2R or 4T4R configuration.
3. 3. The method of claim 1, wherein the heterogeneous computing architecture of fpga+gpu+cpu is divided into tasks in which FPGA is responsible for low latency base signal processing, GPU is responsible for complex algorithm acceleration, and CPU is responsible for system control and task scheduling.
4. 4. The method of claim 1, wherein the software-implemented waveform generation supports the generation of any complex waveform such as LFM, phase coding (BPSK/QPSK), OFDM, etc., waveform parameters including pulse width, bandwidth, repetition frequency, and modulation scheme.
5. 5. The method of claim 1, wherein the pulse compression employs a frequency domain FFT-accelerated convolution implementation to suppress side lobe levels below-40 dB by adding a hanning window or chebyshev window.
6. 6. The method of claim 1, wherein the moving object detection is implemented by a polyphase filter bank and a software parameterization configuration, and the number of points and bandwidth of the filter bank can be dynamically adjusted according to the target speed distribution.
7. 7. The method of claim 1, wherein the distance dynamic window adjustment of the constant false alarm detection is performed by using a 3×3 small window for short distance (< 1.5 m), a 5×5 window for medium distance (1.5 m-8 m), and a 7×7 large window for long distance (> 8 m).
8. 8. The method of claim 1, wherein the clutter multi-algorithm switching mode for constant false alarm detection is that a uniform clutter environment adopts CA-CFAR, a strong clutter edge environment adopts OS-CFAR, and a multi-target environment adopts Min-CFAR.
9. 9. The method of claim 1, wherein the GPS tam clock has an embedded oven controlled crystal oscillator (OCXO) that maintains a frequency offset of < ±20 μs for 3 hours when GPS is lost.
10. 10. The method of claim 1, wherein the multi-station MIMO cooperative detection adopts a2 x2 or 4 x 4 coherent MIMO architecture, and the weight coefficient of the received beam is adjusted by a software algorithm, so that the electronic scanning and the adaptive shaping of the beam are realized, and the scanning range can reach +/-60 °.

Description

Software defined Lei Daquan link integrated signal processing method Technical Field The invention relates to the technical field of radar signal processing, in particular to a software defined Lei Daquan link integrated signal processing method. Background The traditional radar adopts a hardware tight coupling architecture of an analog front end and a special digital back end, and the core function of the traditional radar is realized by completely relying on a special hardware circuit. This architecture has the following technical drawbacks that are not overcome: The function solidification, the core signal processing function is determined by hardware parameters, any function modification needs to redesign a hardware layout and purchase a special chip, the development period is 18-24 months, and the iteration speed of the new technology is extremely slow. The bandwidth is limited by adopting a superheterodyne multi-stage mixing architecture, each stage needs an independent filter, mixer and amplifier, significant signal loss and noise are introduced, the typical instantaneous bandwidth is only 5MHz, and the distance resolution of only 0.75 meters can be realized. The signal processing delay is high, namely the processing delay of a special DSP chip is usually 6.8 mu s, and the real-time detection requirement on a high-speed target cannot be met. The synchronization precision is low, the frequency precision is only +/-10 ppm depending on the synchronization of internal crystal oscillators, and the accumulated time error of 1 hour can reach 36ms, so that the distance measurement error is as high as 5.4X10 6 meters. The system expansibility is poor, the multi-radar node synchronization needs to lay special synchronization cables, the cost is high, the flexibility is poor, and the multi-station MIMO coherent detection cannot be realized. The advent of Software Defined Radar (SDR) has provided the possibility to solve the above problems, but the existing SDR radar technology still has the following disadvantages: Most of all involve a single link of a software defined radar, and a complete full-link integrated solution is not formed The optimization of the signal processing algorithm is insufficient, and particularly the CFAR detection algorithm can only realize single algorithm or fixed window self-adaptation and cannot adapt to complex clutter environments The synchronization precision is not high, and the coherent synchronization of multiple nodes can not be realized Multi-node coordination ability is weak, and beam forming and node coordination without full software are not realized Disclosure of Invention The technical problem to be solved by the invention is how to provide a software definition Lei Daquan link integrated signal processing method, which can break through the constraint of tight coupling of traditional radar hardware, realize the software definition of full link functions such as waveform generation, signal processing, synchronous control and the like, and simultaneously remarkably improve the bandwidth, processing speed, synchronous precision and system expansibility of the radar, and particularly solve the problem that a CFAR detection algorithm in the prior art cannot adapt to a complex clutter environment. In order to solve the technical problems, the invention provides a software defined Lei Daquan link integrated signal processing method, which comprises the following steps: The AD9361 with high integration level is adopted as a general radio frequency front end, the 70MHz-6GHz continuous frequency band is covered, the instantaneous bandwidth can reach 56MHz at the highest, and the configuration of 2T2R or 4T4R is supported; the data transmission between the radio frequency front end and the general computing platform is realized by adopting a USB 3.0 or PCIe Gen5 high-speed interface, and the single-channel data transmission rate can reach 1Gbps; And the FPGA, the GPU and the CPU heterogeneous computing architecture are adopted as a general computing back end, wherein the FPGA is responsible for low-delay basic signal processing, the GPU is responsible for complex algorithm acceleration, and the CPU is responsible for system control and task scheduling. Based on a direct digital frequency synthesis (DDS) technology, directly generating baseband I/Q waveform data through a software algorithm; The method supports the generation of random complex waveforms such as LFM, phase coding (BPSK/QPSK), OFDM and the like, and waveform parameters (pulse width, bandwidth, repetition frequency and modulation mode) can be adjusted in real time; The waveform switching only needs to modify software parameters, and the switching time is less than or equal to 10ms. Pulse compression, namely adopting a software implementation mode of frequency domain FFT acceleration convolution, and inhibiting a side lobe level to be below-40 dB through a Hanning window or a Chebyshev window; moving Target Detection (