北斗导航接收机频率稳定度传递算法

为了提高北斗导航接收机的灵敏度，提升其弱信号跟踪能力，通常需要利用长时间的相干积分来提高环路信噪比。但是，当相干积分时间加长到一定程度时，环路性能反而有所下降，信噪比提升也不能达到理论值。针对由剩余频率误差和晶振误差引起的相干积分能量损失问题，主要研究了频率偏差对环路跟踪性能的影响，并提出了利用频率稳定度传递策略辅助弱信号跟踪的方法，解决了北斗导航接收机弱信号跟踪性能提升的问题，最大程度地改善了相干积分的效果，实现了对弱信号的跟踪。利用软件接收机平台对提出的频率稳定度传递算法进行验证，仿真结果表明该算法可使环路信噪比提升4dB ~5dB，充分说明了其可行性及有效性。

Frequency Stability Transfer Algorithm for Beidou Receiver

A long time coherent integration is usually used to improve the signal to noise ratio of the loop in order to promote the sensitivity and weak signal tracking ability of Beidou receiver. But when the coherent integration time is lengthened to a certain degree, the performance of the loop is decreased, and the signal to noise ratio cannot reach the theoretical value. For the energy loss of coherent integration caused by residual frequency error and crystal error, this paper mainly studies the influence of frequency deviation on loop tracking performance, and puts forward the transfer strategy of frequency stability to assist weak signal tracking. The weak signal tracking performance improvement technology of Beidou navigation receiver has been solved. The effect of coherent integration is optimized to the largest extent and the tracking of weak signal is realized. Lastly, software receiver is used to illustrate the feasibility and effectiveness of the frequency stability transfer algorithm. The result of simulation showed that the proposed algorithm can improve the loop SNR by 4dB ~5dB.