摘要
为了解决多用户混沌通信系统中由于通信用户数目的增多以及混沌序列间的准正交性所引起的信道干扰问题,对不同混沌信号采用施密特(Schmidt)正交化方法产生其对应的正交混沌序列作为扩频码在加性高斯白噪声(AWGN)和瑞利(Rayleigh)衰落信道下研究多用户混沌通信系统中的误码率(BER)。首先将其统计自相关和互相关特性作为刻画正交混沌扩频码序列性能的重要指标,测试并分析各正交混沌序列的统计相关特性,同时也对其互相关特性曲线的均值和方差进行了测试与分析;然后通过两种信道仿真实验获取各正交混沌扩频码的BER,并将其与对应统计相关特性作对比揭示其内在关联性;最后比较分析两种不同信道下多用户混沌通信系统的BER,并揭示信道对其的影响。仿真实验表明,两种信道下相空间混沌信号中的空时正交混沌序列都能获得较低BER,尤其是在Rayleigh衰落信道下的空时正交混沌序列能够获得更低的BER,说明所提方法能更有效地降低多用户通信中信道间的干扰,更有利于多用户通信需要。
In the multi-user chaotic communication system,the increase in the number of communication users as well as the quasi-orthogonality between chaotic sequences cause channel interference.Therefore,the Bit Error Rate （BER） of multiuser chaotic communication system,in which different chaotic signals used Schmidt orthogonalization method to produce the corresponding orthogonal chaotic sequences as spreading code,was studied in Additive White Gaussian Noise （AWGN） and Rayleigh fading channel Firstly,the statistical autocorrelation and cross-correlation characteristics of each orthogonal chaotic sequence were taken as an important index to measure the performance of orthogonal chaotic spreading code sequence,and the statistical correlated characteristics of each orthogonal chaotic sequence and both the mean and variance of the cross-correlation curve were tested and analyzed.Secondly,the BER of each orthogonal chaotic spreading code was obtained by two channel simulation experiments,and the intrinsic correlation found by contrasting the BER of orthogonal chaotic spreading code and its corresponding statistical correlated characteristics was revealed at that time.Lastly,the BERs of multi-user chaotic communication system of two different channels were compared and analyzed and the effect on BER caused by different channels was revealed.The simulation results show that the space-time orthogonal chaotic sequence of phase space chaotic signals can obtain low BER in the two channels,and especially,space-time orthogonal chaotic sequence can obtain lower BER in Rayleigh fading channel,and also show that the proposed method can effectively reduce the interference between the channels in the multi-user communication and is more conducive to the needs of multi-user communication.
出处
《计算机应用》
CSCD
北大核心
2014年第4期963-968,972,共7页
journal of Computer Applications
基金
国家自然科学基金资助项目(61073106)
解放军总装备部武器装备预研项目(9140A25030411HK339)
关键词
多用户混沌通信
扩频码
误码率
正交混沌序列
施密特正交化
multi-user chaotic communication
spreading code
Bit Error Rate （BER）
orthogonal chaotic sequence
Schmidt orthogonalization
