High-sensitivity method and device for capturing Beidou satellite signals

Abstract

The invention discloses a high-sensitivity method for capturing Beidou satellite signals. The method comprises the following steps: firstly, respectively conducting buffer memory on m single-cycle integral results of an I path and m single-cycle integral results of a Q path, and obtaining the sequence [I1, ... Im] of the single-cycle integral results of the I path, and the sequence [Q1, ... Qm] of the single-cycle integral results of the Q path; respectively conducting coherent integration on 2m-1 phase combinations which possibly exist in the m single-cycle integral results in the sequences, and obtaining 2m-1 pairs of integral branches; conducting range obtaining on the single-cycle integral results of the same phase integral branches in the I path and the Q path, and then taking the maximum value in the results as the result of the one-time multi-phase coherent integration; finally conducting noncoherent accumulation on n multi-phase coherent integration results, at last comparing the results with the threshold, and detecting the satellite signals. The invention further discloses a device for capturing the Beidou satellite signals by the adoption of the method for capturing the signals. The method and device overcome the defects that phases of single-cycle integration results are different, and the direct coherent integration can not be achieved, and have the higher satellite signal capturing sensitivity.

Description

technical field [0001] The invention relates to a satellite signal acquisition method, in particular to a high-sensitivity Beidou satellite signal acquisition method and device. Background technique [0002] The acquisition of satellite signals is the correlation operation between the input satellite signal and the spread spectrum code reproduced locally by the satellite navigation receiver (correlation operation refers to multiplying the input signal with the local signal, and then integrating or accumulating), and then according to the correlation of the spread spectrum code Features, detect whether the accumulation result has a peak value, thereby detecting whether the satellite signal exists and the code phase position. [0003] When the satellite signal is strong, the obvious correlation peak can be detected by the integral of one spreading code period. When the satellite signal is weak, it is necessary to use the integration of multiple spreading code periods to incre...

AI Technical Summary

Problems solved by technology

Small coherent integration time (single spread spectrum code period 1 millisecond), it is difficult to detect weak signals, which limits the sensitivity of satellite navigation receivers to capture Beidou satellite signals

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