针对基于无线携能通信(SWIPT, simultaneous wireless information and power transfer)和非正交多址接入(NOMA, non-orthogonal multiple access)的认知中继(CR, cognitive relay)(SWIPT-NOMA-CR)网络,考虑非理想顺序干扰消除(SIC, suc...针对基于无线携能通信(SWIPT, simultaneous wireless information and power transfer)和非正交多址接入(NOMA, non-orthogonal multiple access)的认知中继(CR, cognitive relay)(SWIPT-NOMA-CR)网络,考虑非理想顺序干扰消除(SIC, successive interference cancellation)和信道状态信息(CSI, channel state information)实际情况,研究系统在采用理想、时间开关(TS, time switching)和功率分割(PS, power splitting)3种中继传输方案时次用户的中断性能。推导出次用户中断概率的解析表达式,并通过蒙特卡洛仿真验证理论推导的正确性。实验结果表明,非理想SIC和CSI会导致次用户的中断性能下降,相对于非理想CSI,非理想SIC给系统中断性能带来的损失更大。此外,用户采用PS中继传输方案的中断概率比采用TS方案低,当改变非理想SIC和CSI因子时,采用PS方案用户的中断概率差值比TS方案小,说明PS中继传输方案的可靠性优于TS方案。展开更多
在不完全信道状态信息和非理想连续干扰消除条件下对存在窃听者的非正交多址系统安全性能问题进行研究,提出一个存在窃听者的解码转发中继辅助非正交多址接入系统(Decode and Forward Cooperative Relay in Non-Orthogonal Multiple Acc...在不完全信道状态信息和非理想连续干扰消除条件下对存在窃听者的非正交多址系统安全性能问题进行研究,提出一个存在窃听者的解码转发中继辅助非正交多址接入系统(Decode and Forward Cooperative Relay in Non-Orthogonal Multiple Access System with Eavesdropper,DFCR-E-NOMA)。在该系统中,分析了在不完全的信道状态信息和非理想连续干扰消除同时存在的条件下系统的安全性能,利用中断概率和截获概率表征系统的安全性能,通过蒙特卡罗模拟仿真分析了功率分配系数、信道估计误差对所提系统性能的影响。验证结果表明,在信道条件一定的情况下,可通过设置较高的数据传输速率,在基站或中继处选择合适的功率分配系数能够有效降低窃听者的截获概率。展开更多
In CDMA communication systems, all the subscribers share the common channel. The limitation factor on the system’s capacity is not the bandwidth, but multiuser interference and the near far problem. This paper models...In CDMA communication systems, all the subscribers share the common channel. The limitation factor on the system’s capacity is not the bandwidth, but multiuser interference and the near far problem. This paper models CDMA system from the perspective of mobile radio channels corrupted by additive white noise generated by multipath and multiple access interferences. The system’s receiver is assisted using different combining diversity techniques. Performance analysis of the system with these detection techniques is presented. The paper demonstrates that combining diversity techniques in the system’s receivers markedly improve the performance of CDMA systems.展开更多
Direct-sequence code-division multiple access (CDMA) is considered for multiuser communication network in underwater acoustic channel, where extended multipath and rapid time-variability are encountered. To track and ...Direct-sequence code-division multiple access (CDMA) is considered for multiuser communication network in underwater acoustic channel, where extended multipath and rapid time-variability are encountered. To track and compensate the channel distortion, a decentralized hypothesis-feedback equalization (HFE) algorithm based on chip-rate update has been used[1]. But due to multiple access interference (MAI), its performance suffers degradation. For this reason, successive interference cancellation hypothesis-feedback equalization (SIC-HFE) algorithm is proposed, which combines the capabilities of HFE to track the time-varying channel and SIC implemented by cross-over feedback filters to cancel out the MAI effects between users. Simulation and experiment results show that the proposed algorithm can significantly improve the performance of asynchronous multiuser CDMA underwater communication system.展开更多
文摘针对基于无线携能通信(SWIPT, simultaneous wireless information and power transfer)和非正交多址接入(NOMA, non-orthogonal multiple access)的认知中继(CR, cognitive relay)(SWIPT-NOMA-CR)网络,考虑非理想顺序干扰消除(SIC, successive interference cancellation)和信道状态信息(CSI, channel state information)实际情况,研究系统在采用理想、时间开关(TS, time switching)和功率分割(PS, power splitting)3种中继传输方案时次用户的中断性能。推导出次用户中断概率的解析表达式,并通过蒙特卡洛仿真验证理论推导的正确性。实验结果表明,非理想SIC和CSI会导致次用户的中断性能下降,相对于非理想CSI,非理想SIC给系统中断性能带来的损失更大。此外,用户采用PS中继传输方案的中断概率比采用TS方案低,当改变非理想SIC和CSI因子时,采用PS方案用户的中断概率差值比TS方案小,说明PS中继传输方案的可靠性优于TS方案。
文摘在不完全信道状态信息和非理想连续干扰消除条件下对存在窃听者的非正交多址系统安全性能问题进行研究,提出一个存在窃听者的解码转发中继辅助非正交多址接入系统(Decode and Forward Cooperative Relay in Non-Orthogonal Multiple Access System with Eavesdropper,DFCR-E-NOMA)。在该系统中,分析了在不完全的信道状态信息和非理想连续干扰消除同时存在的条件下系统的安全性能,利用中断概率和截获概率表征系统的安全性能,通过蒙特卡罗模拟仿真分析了功率分配系数、信道估计误差对所提系统性能的影响。验证结果表明,在信道条件一定的情况下,可通过设置较高的数据传输速率,在基站或中继处选择合适的功率分配系数能够有效降低窃听者的截获概率。
文摘In CDMA communication systems, all the subscribers share the common channel. The limitation factor on the system’s capacity is not the bandwidth, but multiuser interference and the near far problem. This paper models CDMA system from the perspective of mobile radio channels corrupted by additive white noise generated by multipath and multiple access interferences. The system’s receiver is assisted using different combining diversity techniques. Performance analysis of the system with these detection techniques is presented. The paper demonstrates that combining diversity techniques in the system’s receivers markedly improve the performance of CDMA systems.
基金National Natural Science Foundation of China (60572098)
文摘Direct-sequence code-division multiple access (CDMA) is considered for multiuser communication network in underwater acoustic channel, where extended multipath and rapid time-variability are encountered. To track and compensate the channel distortion, a decentralized hypothesis-feedback equalization (HFE) algorithm based on chip-rate update has been used[1]. But due to multiple access interference (MAI), its performance suffers degradation. For this reason, successive interference cancellation hypothesis-feedback equalization (SIC-HFE) algorithm is proposed, which combines the capabilities of HFE to track the time-varying channel and SIC implemented by cross-over feedback filters to cancel out the MAI effects between users. Simulation and experiment results show that the proposed algorithm can significantly improve the performance of asynchronous multiuser CDMA underwater communication system.
