Extraction of the In-pulse Characteristics of Signal Based on Direct Sampling from IF signal and quadrature coherent detection;

According to the principle of IF signal sampling and quadrature coherent detection, the scheme sampling the 30 MHz radar IF signal (Bandwidth= 2MHz) directly is presented.

This paper discusses how to implement the direct sampling of radar IF signal with high speed A/D converter and how to resolve one channel of digital signal into two orthogonal digital signals by Bessel interpolation or low pass filtering to realize a digital coherent detection,presents the implementation program based on high speed AD6640 and complex programmable logic device.

According to the principle of correlation detection,an automatic measurement system for extinction ratio of polarizer consisted of monochromator and DSP Lock-in amplifier and compurer is designed not only to eliminate the influence on measurement accuracy caused by drift of intensity of light source but also to obatain approximate extinction spectrum.

Effect of modulation frequency Jitter on coherent detection and its elimination algorithm;

Differential detection and coherent detection based on space-time block codes;

The OSCM system based on coherent detection in atmospheric optical communication is designed and the signal transmission performance of this system is simulated and analyzed in this paper.