High sensitivity fast acquisition algorithm for inter-satellite communication

Abstract:

In an effort to achieve the rapid cooperation of Either micro-satellites or microsatellites and meet the requirements of high sensitivity and fast acquisition of spread spectrum signal proposed by inter-satellite communication link, the principle of common acquisition algorithms was analyzed. In view of the shortcomings of traditional signal acquisition algorithms such as low acquisition sensitivity, long acquisition time and high signal-to-noise ratio requirements, a fast FFT acquisition algorithm for inter-satellite link was proposed. Based on the traditional FFT code phase acquisition method, the algorithm improves the acquisition sensitivity and acquisition speed of the traditional algorithm through multiple parallel architecture, special synchronization sequence, rate reduction decimation, incoherent accumulation and other optimization strategies. In order to test the feasibility of the algorithm, firstly, the limit sensitivity, anti-interference ability and theoretical capture time of the algorithm were derived through theoretical formula. Secondly, the typical task environment was set in MATLAB software to simulate the performance of the algorithm. Finally, the performance of the algorithm was measured by building a hardware test platform. Simulation and hardware tests show that the performance of this algorithm is significantly improved compared with the traditional acquisition algorithm. The ultimate acquisition sensitivity of the improved algorithm is -130 dBm, and the acquisition time is less than 100 ms, which meets the design requirements of satellite communication environment. Its feasibility has been verified in the inter-satellite communication machine of the self-developed tianping-2 satellite. The improved algorithm can also be compatible with different needs of applications in various environments by adjusting the number of parallel paths, non-coherent accumulation times and other elements of the algorithm.