Rician慢衰落信道下的正交循环码M元扩频系统性能分析

Performance analysis of a OCC M-ary spread spectrum system in Rician slow fading channel

本文提出了一种基于正交循环码的M元扩频系统,在发端将一条原型扩频码循环移位构成M个相互正交的扩频码,实现M元扩频,而接收机利用一个时频变换域复数匹配滤波器就可实现正交循环码M元非相干解扩解调。与传统的M元扩频系统相比较,正交循环码M元扩频系统具有很低的复杂度。本文推导出该接收机在Rician慢衰落信道条件下的误比特率的计算公式,给出并分析了计算机仿真结果。

A novel M-ary spread spectrum system based on orthogonal cyclic codes （OCC） is proposed in this paper. At the transmitter of the system, the M spreading codes of each user are generated by circularly shifting the prototype spreading code. At the receiver, a time-frequency transform domain complex number matched-filter is employed to noncoherently despread and demodulate the received signals. Compared with conventional M-ary spread spectrum system, the OCC M-ary spread spectrum system has very low complexity. The BER calculating formulas of the receiver for single user and multiuser in Rieian slow fading channel are derived, and computer simulation results are analyzed.