正交多用户降噪差分混沌键控通信系统  

Differential Chaotic Shift Keying System with Orthogonal Multiuser Noise Reduction

作　　者：吴雪霜 贺利芳[1] 张鹏[1] WU Xueshuang;HE Lifang;ZHANG Peng(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：《西安交通大学学报》2020年第10期108-115,共8页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(61771085);重庆市教育委员会科研基金资助项目(KJ1600407,KJQN201900601)。

摘　　要：针对差分混沌移位键控(DCSK)系统传输速率低和误码性能差的缺点,提出一种正交多用户降噪差分混沌键控(OMU-NRDCSK)通信系统。在发送端的参考时隙之后增加了连续的N个信息时隙,并引入希尔伯特变换使得单个信息时隙内可传输2 bit用户信息,利用希尔伯特变换优良的正交特性可消除用户间干扰,从而提升系统的传输速率和误码性能。在接收端,引入滑动平均滤波器对接收信号进行平均操作,降低了噪声方差,从而提升了系统误码性能。推导了OMU-NRDCSK系统在加性高斯白噪声(AWGN)信道和多径瑞利衰落(RFC)信道下的比特误码率公式并进行了仿真实验。仿真结果表明:在相同条件下,与多用户正交差分混沌键控系统相比,OMU-NRDCSK系统的传输速率提升了约50%,误码性能提升了将近3 dB。A differential chaotic shift keying(OMU-NRDCSK)communication system with orthogonal multiuser noise reduction is proposed to improve the low transmission rate and poor bit error performance of the conventional differential chaos shift keying(DCSK)system.N consecutive information time slots are added after the reference time slot at the modulator,and Hilbert transform is introduced to enable the transmission of two user information bits within a single information time slot and to eliminate the interferences between users in the information time slot.A moving average filter is introduced at the demodulator to average the received signal,which helps to reduce the noise variance and to improve system’s bit error performance.A theoretical formula of bit error rate(BER)for the proposed system is derived under additive white Gaussian noise(AWGN)channel and multi-path Rayleigh fading(RFC)channel,and simulation experiments are performed.The simulation results and a comparison with orthogonal multiuser differential chaos shift keying system under the same conditions show that the transmission rate of OMU-NRDCSK system increases by about 50%,and the bit error performance increases by nearly 3 dB.

关 键 词：差分混沌键控 多用户 滑动平均滤波器 比特误码率 希尔伯特变换 

分 类 号：TN911.3[电子电信—通信与信息系统]