Study of PN-code Capture Method with High Dynamic and Low SNR in Near Space

摘要

Considering the requirement of building near space tt&c system, it designed a parallel PN-code capture method based on FFT. First, it gave a clear derivation of the principle of parallel PN-code capture method, analyzed the capture performance in detail, and finally proved the feasibility of the method through simulation experiment. This method on the one hand weakens the influence of the doppler frequency, and reduces the capture dimension from 2 to 1. At the same time, it achieved the related operations, the relative value of local code and receiving yards was acquired. By this, some special requirements were satisfied and the circuit was simplified, capture speed was improved very much. On the whole, the method overcomes the poor performance under low SNR of traditional capture method, has a good prospect of engineering application.