一种新的二维光正交码的构造与性能分析

摘要

以 OCFHC (一次重合跳频码)作为时间扩频序列,OCS (单重合序列)作为波长跳频序列,构造了一种新的二维光正交码 OCFHC/OCS。分析 OCFHC/OCS 的码字性能,得到了码字的互相关均值表达式,并对该码字的误码率进行了仿真比较。仿真结果表明,当码重和任意两个相邻“切普”波长的最小间隔一定时,增加 OCFHC/OCS 码的跳波长数,不仅可以降低MWOCDMA (多波长光码分多址)系统的误码率,还可以增加码字容量；与 OOC(光正交码)/OCS 码相比,OCFHC/OCS 码的码字性能更优。%This paper constructs a novel two-dimensional(2-D)Optical Orthogonal Code(OOC)named OCFHC/OCS by using the One-Coincidence Frequency Hopping Code (OCFHC)for time spreading sequence and the One-Coincidence Sequence (OCS)for wavelength hopping sequence.Then it analyzes the codeword performances of OCFHC/OCS,obtains its average cross-correlation expression and simulates and compares its BER.Simulation results indicate that when the code weight and the minimum gap between the two adjacent chip wavelengths are fixed,increasing the number of hopping wavelength does not only reduce the BER of OCFHC/OCS system,but also increase the cardinality and compared with OOC/OCS code,the codeword performance of OCFHC/OCS is even better.