An Effective Scheme of M-Ary Spread Spectrum System Based on Orthogonal Spread Spectrum and CPSK

A hybrid M-ary spread spectrum (SS) communication scheme which combined with orthogonal SS and CPSK technique is proposed. Based on dual orthogonal SS, every SS code is treated as original code to adopt CPSK modulation, the unattached synchronous code is chosen to achieve system synchronization. At the receiver, A circular correlator based on transform domain processing is employed to de-spread the received signals. Compared with M-ary SS and CPSK, the proposed scheme is able to obtain higher bandwidth efficiency, stronger anti-intercept capability, and better synchronous performance. The Monte-Carlo simulation results demonstrate that the proposed scheme can achieve better synchronous and bit error rate (BER) performance under additional white gauss noise channel models.

Performance Analysis of Orthogonal Spread Codes for Minimum Essential Communication

By the requirements of reliable wireless communication, a new composite code scheme is proposed for orthogonal spreading codes in order to improve synchronization and error performance, which is based on certain criteria to select the composite codes. Simulation shows that the correlation property of the screened composite codes and the bit error rate performance are better than that of other composite codes.