Method for removing telegraph text position influence in capturing satellilte navigation signal

Abstract

The invention relates to a method for removing telegraph text position influence in capturing a satellilte navigation signal. A coherent integration time span is enlarged to the whole telegraph text position length, thereby improving the sensitivity of capture by 3dB. The method comprises the following steps: generating pseudo-random code data with equal chip number with a telegraph text position on local and performing zero filling operation to the pseudo-random code data, wherein the length of a PN sequence of a local pseudo-random code subject to zero filling is integral power of 2; acquiring sampling data with equal chip number with the PN sequence as an S sequence; obtaining an R sequence by IFFT operation after the result of a first FFT operation of the S sequence is multiplied by a conjugated result of the FFT operation of the PN sequence; entering a tracking link if the maximum value of the S sequence exceeds a judgment threshold value; performing a second FFT operation to the S sequence if the maximum value of the R sequence does not exceed the judgment threshold value, wherein N chips are moved from an operation starting point, N is equal to half of the chip number of the telegraph text position; then performing IFFT operation and taking a new R sequence to do capturing judgment.

Description

technical field [0001] The invention relates to the field of satellite navigation and positioning, in particular to a method for removing the influence of message bits in satellite navigation signal acquisition. Background technique [0002] The acquisition of satellite navigation signals is a two-dimensional search process of code phase and frequency. At present, the acquisition methods for satellite navigation signals can be divided into two types according to the detection method: coherent method and non-coherent method. The non-coherent method does not improve the processing gain of the signal much, and the effect is relatively poor; while the coherent method can provide a large processing gain, such as figure 1 shown. Depend on figure 1 It can be seen that increasing the length of coherent accumulation time can effectively improve the system processing gain, that is, improve the capture sensitivity of the system; but the length of coherent time is affected by the mes...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to overcome the defect that the processing gain is affected by the message position in the existing capture method, and provide a method for removing the influence of the message position in the satellite navigation signal capture process. Technical means, expand the time length of coherent integration to the length of the entire message bit, eliminate the influence of message bits on the correlation results, and increase the capture sensitivity by 3dB

Images