降噪改进型多用户多进制CDSK混沌通信系统  

Chaotic Communication System of Noise Reduction Improved Multiple User Multiple Ary Correlated Delay Shift Keying

作　　者：贺利芳[1] 王磊[1] 张天骐[1] HE Lifang;WANG Lei;ZHANG Tianqi(School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)

机构地区：[1]重庆邮电大学通信与信息工程学院,重庆400065

出　　处：《华南理工大学学报（自然科学版）》2022年第10期94-105,共12页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(61771085);重庆市自然科学基金面上项目(cstc2021jcyj-msxmX0836);重庆市教育委员会科研项目(KJQN201900601)。

摘　　要：针对相关延迟移位键控系统(CDSK)传输效率较差的缺点,设计出一种基于施密特正交降噪改进型多用户多进制相关延迟移位键控(NR-I-MUMA-CDSK)混沌通信系统。该系统在发送端利用施密特正交化产生N组不同的正交混沌序列,将产生的序列分别复制P次,结合多进制信息映射和多载波技术,使每个用户可以携带K个数据比特,并设计将N个用户信息通过N个不同正交混沌信号承载叠加后,在一条载波上进行传输,提升系统的传输速率和能量效率。接收端采用滑动平均滤波器处理信号,使噪声方差由N_(0)/2降低至N_(0)/2P,减小噪声干扰,进而减小系统误码率。对该系统在加性高斯白噪声(AWGN)信道和Rayleigh衰落信道下分别进行了理论公式推导和系统仿真分析。结果显示,相比CDSK文中系统提高了系统的信息传输速率和能量效率,且信息传输速率随N和K不断提升,同时随着K的增加,平均比特能量减少了接近100%。文中还对不同参数对系统误码率的影响进行仿真验证,结果表明系统误码率在两种信道下,均与P和进制数M成反比,与N和R成正比,与理论公式推导结果一致;同时在Ray-leigh衰落信道下对路径数L和不同路径增益下进行仿真,验证了路径数和路径增益对误码率的影响。相较于多种混沌通信系统,文中系统误码率大大降低,且系统误码率随着M的增大而减小,证明了该系统具有很好的理论价值及实际工程意义。In view of the poor transmission efficiency of Correlation Delay Shift Keying(CDSK)system,this studyproposed a noise reduction improved multiple user multiple ary correlated delay shift keying(NR-I-MUMA-CDSK)basedon Schmidt Orthogonalization Chaotic communication system.The system uses Schmidt orthogonalisation to generateN different sets of orthogonal chaotic sequences at the transmitter side,and then copies the generated sequences P times.It also employed multiple ary information mapping and multi-carrier technology,enabling each user to carry K bits ofdata.It also designed to transmit N sets of user information on a single carrier wave by superimposing N different or-thogonal chaotic signal carriers.The transmission rate and energy efficiency of the system were improved.The receiveruses the moving average filter to process the signal,reducing the noise variance from N_(0)/2 to N_(0)/2P.This reduces noiseinterference,which in turn reduces the system bit error rate(BER).The theoretical formula derivation and simulationanalysis of the system in Additive White Gaussian Noise(AWGN)and Rayleigh fading channel were carried out re-spectively.The results show that,compared with CDSK,the system improves the information transmission rate andenergy efficiency.The information transfer rate increases with N and K,and the average bit energy decreases by nearly100%with K.The effects of different parameters on the system BER were verified by simulation.The results show thatthe system BER is inversely proportional to P and the binary number M,directly proportional to N and R,and consistentwith the deduction of theoretical formulas under both channels.The effects of path number L and path gain on the biterror rate were verified by simulation in Rayleigh fading channel.Compared with many chaotic communication systems,the system BER is greatly reduced,and the system BER decreases with the increase of M,which proves that the systemhas good theoretical value and practical engineering significance.

关 键 词：混沌通信 相关延迟移位键控系统 多用户 多进制 施密特正交化 多载波 

分 类 号：TN911.3[电子电信—通信与信息系统]