NOrth-MDPSK系统的最佳检测算法

在多进制正交扩频MDPSK复合调制系统中,现有的检测算法先后独立地进行正交扩频比特与差分相位比特的检测,这使得差分相位比特检测性能与正交检测的性能息息相关,限制了整个系统的误比特性能。针对这一情况,本文基于最大后验概率(MAP)准则,提出了NOrth-MDPSK最佳检测算法。该算法根据差分相位检测的特点,充分利用前后两个符号周期内所有的正交相关值,联合检测当前符号的正交扩频比特和差分比特。仿真结果表明,本文所提算法能够有效地缓解正交检测的性能对系统性能的限制。

The Optimum Detection Algorithm for NOrth-MDPSK

For N-ary Orthogonal Spread Spectrum with MDPSK(NOrth-MDPSK)signal,existing detection algorithm detects the orthogonal signal and DPSK signal successively and independently.And the BER performance of DPSK signal depends heavily upon the detection performance of orthogonal signal.The performance of the whole system is hence limited.To mitigate this situation,this paper derives the optimum detection algorithm for NOrth-MDPSK signals based on the criterion of maximum a posteriori probability(MAP). In accordance with the detection characteristic of DPSK signals,the proposed algorithm takes full advantage of all despread orthogonal symhOols in two successive symbols interval and detects the orthogonal signal and DPSK signal of current symbol jointly.The computer simulation in the end confirms the effectiveness of the proposed algorithm.