论文部分内容阅读
为了解决直接序列扩频(DSSS)接收机中的载波恢复问题,将快速Fourier变换(FFT)与帧同步相结合,提出一种联合的载波恢复算法。基于FFT对频偏的估计结果,利用电文中的帧头数据呈现的特殊性质辅助载波恢复。仿真结果表明:当频偏超出FFT可估计范围1倍时,仍然可以通过帧同步辅助进行正确载波恢复,在同样的预检测积分条件下将鉴频范围扩大1倍至±Rs/2(Rs为预检测积分频率)。该方法简单易行,可将DSSS信号同步的效率提高1倍。
In order to solve the problem of carrier recovery in direct sequence spread spectrum (DSSS) receivers, a fast Fourier transform (FFT) is combined with frame synchronization to propose a combined carrier recovery algorithm. Based on the FFT estimation of frequency offset, the special property of the frame header data in the message is used to assist the carrier recovery. The simulation results show that when the frequency offset is beyond 1 times of the FFT estimable range, the correct carrier recovery can still be performed by using the frame synchronization assistant, and the frequency discrimination range can be doubled to ± Rs / 2 under the same pre-detection integration condition (Rs is Pre-test integration frequency). This method is simple and easy, and can double the efficiency of DSSS signal synchronization.