摘要
QPSK扩频调制信号的载频在SNR很低的时候基本检测不到或者误差很大,传统的四次方法仅能在信号带宽内SNR大于0dB时检测到载频分量。本文提出一种新的基于码周期的延时相乘方法,在扩频码长1023位,信号带宽内SNR等于-13dB的情况下,仍能够精确估计载频,其精度仅受限于FFT的分辨率。
The carrier of DSSS/QPSK signal is hard to detect in low SNR, and the conventional method of quartic can only work when SNR measured in the signal bandwidth 〉 0dB. In this paper, a new method, delay multiplication based on code period, is proposed. When the length of PN code = 1023, and SNR measured in the signal bandwidth = - 13dB, the carrier can still be estimated precisely, and the precision is only limited to the FFT resolution.
出处
《电子信息对抗技术》
2007年第6期9-11,32,共4页
Electronic Information Warfare Technology
