针对差分混沌-相关延时移位键控(DC-CDSK)存在的码间干扰而造成的比特误码率较高问题,提出了一种无码间干扰DC-CDSK混沌通信方案。通过改变混沌信号发生器的结构,确保发送的两路混沌信号严格正交,彻底解决了判决变量中码间干扰问题。推...针对差分混沌-相关延时移位键控(DC-CDSK)存在的码间干扰而造成的比特误码率较高问题,提出了一种无码间干扰DC-CDSK混沌通信方案。通过改变混沌信号发生器的结构,确保发送的两路混沌信号严格正交,彻底解决了判决变量中码间干扰问题。推导了在高斯白噪声信道中的比特误码率公式并完成仿真,结果表明,在一定信噪比和扩频因子条件下无码间干扰DC-CDSK比特误码率比原系统提高了2~3 d B。展开更多
为了提高水声通信的性能,提出了一种联合运用 M 元扩频(MSS)通信和 Pattern时延差编码(PDS)水声通信体制,并采用单阵元被动式时间反转镜(PTRM)来实现声信道均衡的深海远程水声通信方案。该方案的 M 元扩频-Pattern 时延差编码通信技术...为了提高水声通信的性能,提出了一种联合运用 M 元扩频(MSS)通信和 Pattern时延差编码(PDS)水声通信体制,并采用单阵元被动式时间反转镜(PTRM)来实现声信道均衡的深海远程水声通信方案。该方案的 M 元扩频-Pattern 时延差编码通信技术既能胜任远程水声通信,又能提高通信速率;单阵元被动式时间反转镜信道均衡技术既可抑制多途扩展产生的码间干扰,又能提高信噪比。根据深海声道特性分析,该方案将通信固定节点置于声道轴以获取会聚增益,提高通信距离。计算机仿真结果证明,所提出的深海远程水声通信方案具有很好的鲁棒性和可行性。展开更多
The problem of inter symbol interference( ISI) in wireless communication systems caused by multipath propagation when using high order modulation like M-Q AMis solved. Since the wireless receiver doesn't require a ...The problem of inter symbol interference( ISI) in wireless communication systems caused by multipath propagation when using high order modulation like M-Q AMis solved. Since the wireless receiver doesn't require a training sequence,a blind equalization channel is implemented in the receiver to increase the throughput of the system. To improve the performances of both the blind equalizer and the system,a joint receiving mechanismincluding variable step size( VSS) modified constant modulus algorithms( MC-MA) and modified decision directed modulus algorithms( MD DMA) is proposed to ameliorate the convergence speed and mean square error( MSE) performance and combat the phase error when using high order QAM modulation. The VSS scheme is based on the selection of step size according to the distance between the output of the equalizer and the desired output in the constellation plane. Analysis and simulations showthat the performance of the proposed VSS-MCMA-MD DMA mechanismis better than that of algorithms with a fixed step size. In addition,the MCMA-MDDMA with VSS can performthe phase recovery by itself.展开更多
文摘针对差分混沌-相关延时移位键控(DC-CDSK)存在的码间干扰而造成的比特误码率较高问题,提出了一种无码间干扰DC-CDSK混沌通信方案。通过改变混沌信号发生器的结构,确保发送的两路混沌信号严格正交,彻底解决了判决变量中码间干扰问题。推导了在高斯白噪声信道中的比特误码率公式并完成仿真,结果表明,在一定信噪比和扩频因子条件下无码间干扰DC-CDSK比特误码率比原系统提高了2~3 d B。
文摘为了提高水声通信的性能,提出了一种联合运用 M 元扩频(MSS)通信和 Pattern时延差编码(PDS)水声通信体制,并采用单阵元被动式时间反转镜(PTRM)来实现声信道均衡的深海远程水声通信方案。该方案的 M 元扩频-Pattern 时延差编码通信技术既能胜任远程水声通信,又能提高通信速率;单阵元被动式时间反转镜信道均衡技术既可抑制多途扩展产生的码间干扰,又能提高信噪比。根据深海声道特性分析,该方案将通信固定节点置于声道轴以获取会聚增益,提高通信距离。计算机仿真结果证明,所提出的深海远程水声通信方案具有很好的鲁棒性和可行性。
基金Supported by the National Natural Science Foundation of China(6100201461101129+1 种基金6122700161072050)
文摘The problem of inter symbol interference( ISI) in wireless communication systems caused by multipath propagation when using high order modulation like M-Q AMis solved. Since the wireless receiver doesn't require a training sequence,a blind equalization channel is implemented in the receiver to increase the throughput of the system. To improve the performances of both the blind equalizer and the system,a joint receiving mechanismincluding variable step size( VSS) modified constant modulus algorithms( MC-MA) and modified decision directed modulus algorithms( MD DMA) is proposed to ameliorate the convergence speed and mean square error( MSE) performance and combat the phase error when using high order QAM modulation. The VSS scheme is based on the selection of step size according to the distance between the output of the equalizer and the desired output in the constellation plane. Analysis and simulations showthat the performance of the proposed VSS-MCMA-MD DMA mechanismis better than that of algorithms with a fixed step size. In addition,the MCMA-MDDMA with VSS can performthe phase recovery by itself.