摘要
以同步二次素数码(SQPC)作为时间扩频序列,单重合序列(OCS)作为波长跳频序列,构造了一种新的二维光正交码SQPC/OCS,并对其误码性能及码字容量进行了理论分析和仿真比较。理论分析表明:在同码长、同波长数条件下,SQPC/OCS与2D-QPC误码率相等,但SQPC/OCS波长数可以是任何数,不局限于素数,从而增加波长码片可以降低误码率;与扩展素数码(EPC)EPC/OCS相比,SQPC/OCS误码率更低。SQPC/OCS码字容量远远高于2D-QPC和。EPC/OCS码字容量。仿真结果表明:当p=7、q=13时,SQPC/OCS误码率比2D-QPC降低接近2个数量级;当p=11、q=15时,SQPC/OCS与EPC/OCS相比,当用户数为20时,误码率相差达4个数量级。
A new two-dimensional optical orthogonal code named SQPC/OCS was constructed with synchronous quadratic prime code(SQPC) as time spreading sequence and one-coincidence sequence(OCS) as wavelength hopping sequence.The performances of bit error ratio(BER) and word capacity were compared by analysis and simulation.Theoretical analysis show that SQPC/OCS has the same BER as 2D-QPC(Quadratic prime code) when given the same code length and same number of wavelength,but SQPC/OCS can reduce its BER by increasing the number of wavelength which is not limited to a prime number.Compared with extend prime code(EPC) EPC/OCS,SQPC/OCS gets lower BER.Moreover,the code capacity of SQPC/OCS was much more than that of 2D-QPC and EPC/OCS.The simulation shows that the bit error rate(BER) of SQPC/OCS is nearly two orders of magnitude lower and four orders of magnitude lower than that of 2D-QPC(p = 7 and q = 13) and EPC/OCS(p = 11 and q = 15) while the number of synchronous users equals 20,respectively.
出处
《量子电子学报》
CAS
CSCD
北大核心
2015年第2期251-256,共6页
Chinese Journal of Quantum Electronics
基金
广西高校自然科学基金重点项目(201202ZD010)
桂林科学技术发展项目基金(20120104-18)
关键词
光通信
OCDMA系统
单重合序列
误码率
码容量
optical communication
optical code division multiple access system
one-coincidence sequence
bit error ratio
code capacity