一种改进的DSSS系统的码捕获技术

针对低信噪比条件下直接序列扩频(DSSS)系统的码捕获问题,提出了差分非相干累加的PN码捕获技术。研究了差分相干与差分非相干码捕获技术的工作性能,仿真结果表明,差分非相干码捕获技术具有更强的抗载波频偏能力。在此基础上,克服调制数据对码捕获的影响,提出了一种改进的差分非相干码捕获技术,即差分非相干累加的码捕获技术。仿真研究证明了差分非相干累加码捕获技术比差分非相干码捕获技术有4 dB的改善,其更能适应低信噪比条件工作。

An Advanced Code Acquisition Technology of DSSS System

Aiming at the code acquisition problem in DSSS system under low signal to noise ratio(SNR),a differential non-coherent accumulation code acquisition technique is proposed.Performance of differential coherent and differential non-coherent code acquisition technique is researched.Simulation result shows that differential non-coherent code acquisition technique has a better capability against carrier frequency offset.On this base,the effect of modulation data on is code acquisition overcome.An advanced differential non-coherent code acquisition technique(differential non-coherent accumulation technique) is proposed.The simulation shows that the differential non-coherent accumulation code acquisition technique improves 4 dB compared with differential non-coherent code acquisition technique,and can better adapt to low SNR environment.