针对舱内无线光传输系统多种干扰问题,比如多径损耗和突发干扰等,提出一种基于链路状态的自适应干扰消除技术,该方法分析舱内链路状态,完成链路状态估计,采用环境自适应的变遗忘因子RLS(recursive least squares)算法,针对不同链路状态...针对舱内无线光传输系统多种干扰问题,比如多径损耗和突发干扰等,提出一种基于链路状态的自适应干扰消除技术,该方法分析舱内链路状态,完成链路状态估计,采用环境自适应的变遗忘因子RLS(recursive least squares)算法,针对不同链路状态采取差异化的干扰消除策略,以提高舱内通信质量。仿真结果表明:该算法在尽力避免增加算法复杂度的条件下,相对于传统固定遗忘因子算法,在平稳状态下优先保证传输的误码性能,在链路状态变化时具有更好的收敛性能,灵活适应了舱内多种传输情况。展开更多
Recently,the increasing demand of radio spectrum for the next generation communication systems due to the explosive growth of applications appetite for bandwidths has led to the problem of spectrum scarcity.The potent...Recently,the increasing demand of radio spectrum for the next generation communication systems due to the explosive growth of applications appetite for bandwidths has led to the problem of spectrum scarcity.The potential approaches among the proposed solutions to resolve this issue are well explored cognitive radio(CR)technology and recently introduced non-orthogonal multiple access(NOMA)techniques.Both the techniques are employed for efficient spectrum utilization and assure the significant improvement in the spectral efficiency.Further,the significant improvement in spectral efficiency can be achieved by combining both the techniques.Since the CR is well-explored technique as compared to that of the NOMA in the field of communication,therefore it is worth and wise to implement this technique over the CR.In this article,we have presented the frameworks of NOMA implementation over CR as well as the feasibility of proposed frameworks.Further,the differences between proposed CR-NOMA and conventional CR frameworks are discussed.Finally,the potential issues regarding the implementation of CR-NOMA are explored.展开更多
分区频域卡尔曼滤波(Partitioned block frequency domain Kalman filtering,PBFDKF)因其收敛速度快、稳态误差小的优势被应用在自适应滤波声反馈抑制(Adaptive feedback cancellation,AFC)。然而,当声反馈路径发生突变时,卡尔曼滤波会...分区频域卡尔曼滤波(Partitioned block frequency domain Kalman filtering,PBFDKF)因其收敛速度快、稳态误差小的优势被应用在自适应滤波声反馈抑制(Adaptive feedback cancellation,AFC)。然而,当声反馈路径发生突变时,卡尔曼滤波会进入锁死状态,难以再次跟踪。本文提出一种融合神经网络的卡尔曼滤波啸叫抑制状态检测算法(Kalman⁃filter⁃based AFC with state detection model,KFSD)。该系统将卡尔曼滤波声反馈抑制系统的传声器采集信号、残差信号和滤波器更新量作为输入特征,通过神经网络对卡尔曼滤波的状态误差协方差矩阵进行修正,从而实现路径突变情况下的再次跟踪和收敛。仿真实验结果验证了所提算法具有较高的正判率、较低的虚警率和较短的延迟帧数,算法同时具备快速再跟踪性能,提高了声反馈抑制效果。展开更多
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
文摘针对舱内无线光传输系统多种干扰问题,比如多径损耗和突发干扰等,提出一种基于链路状态的自适应干扰消除技术,该方法分析舱内链路状态,完成链路状态估计,采用环境自适应的变遗忘因子RLS(recursive least squares)算法,针对不同链路状态采取差异化的干扰消除策略,以提高舱内通信质量。仿真结果表明:该算法在尽力避免增加算法复杂度的条件下,相对于传统固定遗忘因子算法,在平稳状态下优先保证传输的误码性能,在链路状态变化时具有更好的收敛性能,灵活适应了舱内多种传输情况。
文摘Recently,the increasing demand of radio spectrum for the next generation communication systems due to the explosive growth of applications appetite for bandwidths has led to the problem of spectrum scarcity.The potential approaches among the proposed solutions to resolve this issue are well explored cognitive radio(CR)technology and recently introduced non-orthogonal multiple access(NOMA)techniques.Both the techniques are employed for efficient spectrum utilization and assure the significant improvement in the spectral efficiency.Further,the significant improvement in spectral efficiency can be achieved by combining both the techniques.Since the CR is well-explored technique as compared to that of the NOMA in the field of communication,therefore it is worth and wise to implement this technique over the CR.In this article,we have presented the frameworks of NOMA implementation over CR as well as the feasibility of proposed frameworks.Further,the differences between proposed CR-NOMA and conventional CR frameworks are discussed.Finally,the potential issues regarding the implementation of CR-NOMA are explored.
文摘分区频域卡尔曼滤波(Partitioned block frequency domain Kalman filtering,PBFDKF)因其收敛速度快、稳态误差小的优势被应用在自适应滤波声反馈抑制(Adaptive feedback cancellation,AFC)。然而,当声反馈路径发生突变时,卡尔曼滤波会进入锁死状态,难以再次跟踪。本文提出一种融合神经网络的卡尔曼滤波啸叫抑制状态检测算法(Kalman⁃filter⁃based AFC with state detection model,KFSD)。该系统将卡尔曼滤波声反馈抑制系统的传声器采集信号、残差信号和滤波器更新量作为输入特征,通过神经网络对卡尔曼滤波的状态误差协方差矩阵进行修正,从而实现路径突变情况下的再次跟踪和收敛。仿真实验结果验证了所提算法具有较高的正判率、较低的虚警率和较短的延迟帧数,算法同时具备快速再跟踪性能,提高了声反馈抑制效果。
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。
