新型直接序列扩频通信方法OACSCDCSTPCD

In response to the problem of limited performance and low spectral efficiency in complex multipath environ-ments of traditional direct sequence spread spectrum communication,a cyclic prefix(CP)block transmission structure spread spectrum system with a time-frequency hybrid direct sequence spread spectrum receiver structure was proposed.The system adopted maximum ratio combination(MRC)in the frequency domain to achieve equalization and de-spreading processes simultaneously,while achieving optimal reception performance and omitting the IFFT process to reduce computational complexity significantly.On this basis,it was proposed to replace the m-sequence with the constant amplitude zero auto correlation(CAZAC)sequence as the spread spectrum sequence,which significantly improved the system performance without increasing computational complexity.Finally,a high-speed spread spectrum communication method based on cyclic code shift keying(CCSK)was proposed to solve the problems of low spectrum utilization effi-ciency and limited transmission rate in traditional direct sequence spread spectrum.By utilizing the property of Fourier transform time-domain cyclic shift,a low implementation complexity CCSK decoding method was designed,which re-duced the multiplication number required for CCSK de-spreading by O(N2)reduced to O(Nlog N),greatly reducing resource consume.The simulation results show that compared to existing direct sequence spread spectrum methods,the proposed method achieves approximately 3 dB gain in both Gaussian and complex multipath channel environments.