Incoherent joint capture method and device

Abstract

The embodiment of the invention provides an incoherent joint capture method and device, and the method comprises the steps: dividing an input signal into M groups of sub-input signals, carrying out the FFT conversion of the sub-input signals, and carrying out the circumferential shift of the M groups of FFT sequences; carrying out full-coherence accumulation on M groups of circumference correlation results of the subcarriers to obtain an output plane of the coherence accumulation results, and replacing the frequency offset dimension of the output plane with a Doppler rate dimension; accumulating coherence of doppler rate-code phase two-dimensional plane of all subcarriers; and comparing each peak value on the statistical plane with a preset monitoring threshold to obtain a correlation peakexceeding the monitoring threshold; and according to the Doppler factor and the code phases of the correlation peaks on the Doppler rate-code phase two-dimensional planes of the subcarriers, respectively obtaining the frequency offset value and the propagation delay of the subcarrier. According to the embodiment of the invention, the total spread spectrum gain distributed on each subcarrier is fully utilized, and the signal-to-noise ratio performance of the capturing system is improved on the basis of not increasing the algorithm complexity.

Description

technical field [0001] The present invention relates to the technical field of spread spectrum communication, and more specifically, relates to non-coherent joint acquisition. Background technique [0002] The common platform for the multi-carrier direct spread spectrum system is a low-orbit satellite. This communication system has the characteristics of low signal-to-noise ratio, high dynamics, wide frequency band, and high spreading ratio. high demands. Due to the short transit time of the satellite and the small communication time window, short-frame burst system communication is often used for security reasons, which requires that the accurate capture and reception of link signals must be completed in a short time; on the other hand, The Doppler frequency offset and code offset caused by the relative velocity between the satellite and the ground will bring great difficulties to fast acquisition. Similarly, the traditional acquisition method cannot achieve joint accumul...

AI Technical Summary

Problems solved by technology

Compared with the traditional PVT multi-carrier joint acquisition algorithm, this algorithm has significantly improved the detection probability, but in essence it still captures the subcarrier direct spread spectrum system, and still does not make full use of the total spread spectrum distributed on each subcarrier. Gain, limited improvement in signal-to-noise ratio performance

Images