An improved pmf-fft method suitable for p-code capture

Abstract

The invention belongs to the field of signal acquisition of satellite navigation systems, and relates to an improved PMF-FFT method for P-code acquisition of a satellite navigation system. The methodcomprises the following steps: step S1, setting a total coherent integration time T and a piecewise coherent integration time T, and calculating a quantity K of partial matched filters and a length 2Xof the partial matched filters; step S2, calculating an operation time required by the K partial matched filters to perform a single PMF-FFT algorithm, its own power loss and envelope detection loss;step S3, determining a minimum non-coherent accumulation number required to reach the equivalent decision signal-to-noise ratio; step S4, obtaining a total operation time under the premise of the combined parameter values by calculation; and step S5, changing the value of the combined parameter values, and repeatedly executing the steps S1-S4 until the set number of times, so that the parameter value with the shortest total operation time of the PMF-FFT algorithm is the combined parameter value optimization result. The method provided by the invention improves the calculation speed while meeting the requirements of the acquisition performance, and enables the system modeling more accurate.

Description

technical field [0001] The invention belongs to the field of satellite navigation system signal capture, in particular to an improved PMF-FFT method for satellite navigation system P code capture. Background technique [0002] Usually, the capture of the P code is guided by the C / A code, but due to the short period of the C / A code and the low code rate, it is easy to be interfered and deceived by the enemy. In the environment of GPS navigation warfare and electronic countermeasures, it is required The GNSS receiver can accurately and quickly directly capture the P code, ensuring the normal use of the wartime satellite navigation system. The period of P code is long and the code rate is high. If the traditional acquisition method is used, it will take a long time to acquire it. Especially under high dynamics and large Doppler frequency shift, the traditional pseudo code acquisition method is difficult to realize. Therefore, the key to P code acquisition is how to reduce the ...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the above-mentioned technical problems, the present invention provides a PMF-FFT optimization design method suitable for direct capture of P codes that takes into account both system loss and capture performance, effectively solving the problem of various parameter designs in the entire PMF-FFT algorithm system in the prior art Incomplete consideration of optimization and long operation time of the capture process

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