Beidou B1 signal high sensitivity capturing method based on chirp-Z transform

Abstract

The invention belongs to the field of satellite receiver baseband signal processing and relates to a Beidou B1 signal high sensitivity capturing method based on chirp-Z transform, so as to reduce signal energy loss caused by FFT computing fence effects and improve the receiver sensitivity. By using a Beidou B1 signal capturing result in a parallel correlation + FFT method, a Doppler frequency rough estimation result and a pseudo code phase are obtained; according to the pseudo code phase of the capturing result, the local pseudo code phase is adjusted, chirp-Z transform capturing is carried out on signals near the Doppler frequency, the capturing peak is effectively improved, and the receiver sensitivity is improved. The method is mainly applied to high sensitivity capturing on Beidou No.2 B1 frequency point satellite navigation signals and can also be applied to capturing and processing on other similar signals.

Description

technical field [0001] The invention belongs to the field of baseband signal processing of satellite receivers, and relates to a high-sensitivity acquisition method of Beidou B1 signals based on linear frequency modulation Z transform. This method is mainly applied to the high-sensitivity acquisition of Beidou-2 B1 frequency point satellite navigation signal, but it can also be applied to other similar signal acquisition processing. Background technique [0002] At present, the search for the Doppler frequency of the satellite signal by the receiver is generally realized by means of FFT transformation. [0003] Due to the influence of the fence effect, when the Doppler frequency is between two FFT spectral lines, the signal energy will be greatly lost, thereby reducing the receiver's acquisition probability of the satellite signal and reducing the receiver's acquisition sensitivity. Increasing the number of FFT points by padding the signal with zero is the most direct way t...

AI Technical Summary

Problems solved by technology

[0003] Due to the influence of the fence effect, when the Doppler frequency is between the two FFT spectral lines, the signal energy will be greatly lost, thereby reducing the probability of the receiver capturing the satellite signal and reducing the receiver's capture sensitivity

Increasing the number of FFT points by padding the signal with zero is the most direct way to reduce the influence of the fence effect, but due to the limitation of the current hardware platform resources, the space for increasing the number of FFT points is limited

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