扩频映射编码中伪随机序列的性能研究

摘要

扩频映射编码系统中,伪随机码的纠错性能至关重要.构造平衡Gold序列,循环移位m序列和移位正交m序列,分析比较其相关特性；计算扩频映射码集的最小码距,证明循环移位m序列和移位正交m序列纠错能力更好；建立系统的数学模型,对采用不同码型的系统误码率进行蒙特卡罗仿真,结果与理论分析吻合.证明选取相关特性好、最小码距大的伪随机序列集,适当增加扩频因子,可以提高扩频编码系统的性能.%The error-correcting performance of pseudo-random sequences is extremely important in spreading mapping encoding system. Balanced Gold sequences were constructed together with cyclic m sequences and cyclic orthogonal m sequences. Analysis of their correlation was given later. The spreading mapping encoding sets were constructed and the minimum distance was calculated. It was indicated that cyclic m sequences and cyclic orthogonal m sequences gained better error-correcting performance. The mathematical model of system is presented. Monte Carlo simulations on BER of system using different sequences were given respectively. The results proved the theoretical analysis. It shows that BER performance could be improved by increasing the spreading factor and selecting pseudo-random sequences with better correlation and minimum distance.