Improved Algorithm Of Quadrature Sampling With Pulse Compression And The Design Of Its Optimized Filter

The algorithm quardrature sampling with pulse compression is most often used in modern Radar receiver. Quardrature sampling is, in fact, sampling in Radar's echo signal to produce the inphase components I(n) and quadrature components Q(n). The former old analog way couldn't assure the phase and amplitude performance of I/Q channel. But with the development of digital processing technique, the use of sampling in intermediate frequency is gradually popularized, old analog way has been replaced by new digital way. Pulse compression is in order to solve the conflict of radar's ability to detect targets and to distinguish targets. This technique is realized by sending LFM signal of large time-width and bandwidth and then making matched filtering to the echo signal.This paper analysized the relationship between sampling frequency fs and the taps N of low pass filter in A/D transform and got a formula expression, which can give reference to the parameter design of quadrature sampling.; aiming at the wave distortion in traditional arithmetic of quadrature sampling with pulse compression, an improved algorithm has been studied and validated in Matlab and get perfecter result. In order to enlarge the detect distance of Radar, a method of part pulse compression is put forward, the realistic sense and the implement scheme is analysized. Further study is made on target velocity measurement of radar, double-channel filter method and another one which based on chirp up and chirp down signal are discussed. At last, all the algorithm discussed above are programmed on DSP TS101 and some typical programme optimizing ways in assembly language are summarized.