A fast pseudo-code-doppler acquisition method for DSSS DPSK signal under high dynamic conditions

Abstract

The invention discloses a pseudo-code-Doppler fast acquisition method of direct spread spectrum DPSK signal under high dynamic state, which comprises the following steps: firstly, downconverting the received intermediate frequency direct spread spectrum DPSK signal by carrier wave; then the Doppler frequency offset is captured by nonlinear transform combined with FFT. Then the carrier wave is corrected by Doppler frequency offset. Then the DSSS DPSK signal is downconverted by the modified carrier wave. Finally, the code phase compression correlator is used to search the DPSK signal compensatedby Doppler and multi-channel continuous-phase local pseudo-code to obtain the pseudo-code estimation. The invention can realize acquisition of DSSS DPSK signal under high dynamic state, the joint estimation of pseudo-code phase and Doppler frequency offset has smaller error performance, better pseudo-code phase acquisition performance and shorter acquisition time, which ensures that the receivedsignal has a better rough synchronization before entering the signal tracking processing module, and has lower complexity, so it has strong practical value.

Description

technical field [0001] The invention belongs to the technical field of direct-spread signal receiver processing, in particular to a pseudo-code-Doppler fast acquisition method for direct-spread DPSK signals under high dynamics. Background technique [0002] The ultimate goal of direct spread DPSK signal receiver processing is to despread and demodulate the transmitted data. The acquisition of pseudocode phase and carrier frequency is the prerequisite for correct despread and demodulation. After the signal is down-converted, the pseudo-code phase acquisition and carrier Doppler frequency offset acquisition are respectively performed. The traditional pseudo-code capture methods include sliding correlation method and matched filter method, and there is a contradiction between capture speed and implementation complexity. At the same time, in a high dynamic environment, there is usually a high radial velocity between the receiver and the transmitter, which makes the received sig...

AI Technical Summary

Problems solved by technology

However, in the prior art, there is no method that can well adapt to the high dynamic environment and achieve a better capture effect, which makes the performance of the direct spread DPSK signal all-digital receiver poor.

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