摘要
在伽罗华有限域理论的基础上,用素域上的二次素数序列对素数码的码函数进行改进。结合MPC和EPC降低互相关值的方法,讨论异步OCDMA系统用户地址码的结构优化。分析MSPC的相关特性:最大互相关为2,最大自相关旁瓣为1,在此基础上,进一步构造出ESPC码字,该码字的自相关旁瓣和互相关的最大值均为1。较之由线性码函数确定的素数码,该码字的峰值旁瓣比大大增加。有利于提高系统传输性能,同时给信号探测提供便利。
Based on Galois theory of definite field, using the square prime sequence, the code function of basic prime code is modified and extended. The auto-correlation and crosscorelation of MSPC, which based on square prime sequence, are analyzed in detail. The maximum auto and cross correlation are 2 and 1 respectively. And then, going through reconstructing the prime sequence and code function, a novel signature code, ESPC has been acquired. Compared to basic OPCs derived from linear prime sequence, the maximum value of auto-correlation of ESPC is reduced from p - 1 to 1 and cross-correlation is reduced from 2 to 1. the ratio of auto-correlation peak to sideband has largely enhanced, which ensures a better system performance and is more advantageous in signal detection.
出处
《量子电子学报》
CAS
CSCD
北大核心
2005年第5期789-793,共5页
Chinese Journal of Quantum Electronics
基金
江苏省高校自然科学基金计划项目资助项目(04jkb510057)国家留学基金委员会面上项目
关键词
光通信
地址码
扩展二次素数码
自相关
码函数
optical communication
signature code： extended square prime code
autocorrelation
code function
