超Nyquist码元速率(FTN)理论的出现为提高通信系统数据传输速率奠定了基础。但是,FTN是以引入码间串扰(ISI)为代价的。这给接收端信号检测工作增加了难度。目前已有学者提出了基于线性频域均衡器(FDE)的FTN接收方案。但是FDE在设计抽头...超Nyquist码元速率(FTN)理论的出现为提高通信系统数据传输速率奠定了基础。但是,FTN是以引入码间串扰(ISI)为代价的。这给接收端信号检测工作增加了难度。目前已有学者提出了基于线性频域均衡器(FDE)的FTN接收方案。但是FDE在设计抽头系数时没有考虑接收滤波器对信道噪声的影响,而且FDE输出的结果仍然存在残余的ISI,因此性能略差。针对上述问题,将接收滤波器对信道噪声的影响考虑进均衡器设计中,并进一步提出了基于预测型判决反馈均衡器(NPDFE)的FTN接收方案,提高了接收性能。仿真结果表明:在BER=10-4条件下,当ρ=0.8时,NPDFE以提升一倍复杂度的代价使得所需的SNR比FDE减少约5 d B。展开更多
极化码是适用于物理层wiretap信道安全模型的一种编码方式,针对在超奈奎斯特(FTN)条件下传输的极化码,设计了一种无需获知窃听信道信噪比(SNR)的帧间链式加密的安全结构。通过混淆结构将对合法接收端可靠而对非法窃听端阻塞的码元进行扩...极化码是适用于物理层wiretap信道安全模型的一种编码方式,针对在超奈奎斯特(FTN)条件下传输的极化码,设计了一种无需获知窃听信道信噪比(SNR)的帧间链式加密的安全结构。通过混淆结构将对合法接收端可靠而对非法窃听端阻塞的码元进行扩散,利用物理层主信道和窃听信道的差异,在每一帧中生成主信道可译而窃听信道不可译的密钥序列,对下一帧进行加密,实现安全容量的帧间传输。仿真结果显示,在FTN加速场景和窃听信道SNR相对于主信道波动的前提下,提出的极化码帧间安全结构可在wiretap信道的平均信道退化程度为0 d B时实现信息的安全传输。展开更多
The M-BCJR algorithm based on the Ungerboeck observation model is a recent study to reduce the computational complexity for faster-than-Nyquist(FTN)signaling[1].In this paper,we propose a method that can further reduc...The M-BCJR algorithm based on the Ungerboeck observation model is a recent study to reduce the computational complexity for faster-than-Nyquist(FTN)signaling[1].In this paper,we propose a method that can further reduce the complexity with the approximately same or better bit error rate(BER)performance compared to[1].The information rate(IR)loss for the proposed method is less than 1%compared to the true achievable IR(AIR).The proposed improvement is mainly by introducing channel shortening(CS)before the M-BCJR equalizer.In our proposal,the Ungerboeck M-BCJR algorithm and CS can work together to defeat severe inter-symbol interference(ISI)introduced by FTN signaling.The ISI length for the M-BCJR algorithm with CS is optimized based on the criterion of the IR maximization.For the two cases=0.5 and=0.35,compared to Ungerboeck M-BCJR without CS benchmark[1],the computational complexities of Ungerboeck M-BCJR with CS are reduced by 75%.Moreover,for the case=0.35,the BER performance of Ungerboeck M-BCJR with CS outperforms that of the conventional M-BCJR in[1]at the low signal to noise ratio region.展开更多
Faster-than-Nyquist(FTN)signaling can improve the spectrum efficiency(SE)of the transmission system.In this paper,we propose a coded modulation FTN(CM-FTN)transmission scheme with precoder and channel shortening(CS)op...Faster-than-Nyquist(FTN)signaling can improve the spectrum efficiency(SE)of the transmission system.In this paper,we propose a coded modulation FTN(CM-FTN)transmission scheme with precoder and channel shortening(CS)optimization to improve bit error rate(BER)performance and reduce the complexity of FTN equalizer.In our proposal,the information rate(IR)or spectral efficiency(SE)is employed and verified as a better performance metric for CM-FTN than the minimum Euclidian distance(MED).The precoder of CM-FTN is optimized for maximizing the IR criterion using the bare-bones particle swarm optimization(BB-PSO)algorithm.Further,a three-carrier CM-FTN system model is used to capture the broadening effect of precoder.Also targeting for the IR maximization,the inter-symbol interference(ISI)length for CS is optimized to reduce the receiver complexity without performance loss.Simulation results demonstrate that our method has a 0.6dB precoding gain compared with the nonprecoding scheme and a maximum of 87.5%of the complexity of FTN equalizer is reduced without BER loss.展开更多
文摘超Nyquist码元速率(FTN)理论的出现为提高通信系统数据传输速率奠定了基础。但是,FTN是以引入码间串扰(ISI)为代价的。这给接收端信号检测工作增加了难度。目前已有学者提出了基于线性频域均衡器(FDE)的FTN接收方案。但是FDE在设计抽头系数时没有考虑接收滤波器对信道噪声的影响,而且FDE输出的结果仍然存在残余的ISI,因此性能略差。针对上述问题,将接收滤波器对信道噪声的影响考虑进均衡器设计中,并进一步提出了基于预测型判决反馈均衡器(NPDFE)的FTN接收方案,提高了接收性能。仿真结果表明:在BER=10-4条件下,当ρ=0.8时,NPDFE以提升一倍复杂度的代价使得所需的SNR比FDE减少约5 d B。
文摘极化码是适用于物理层wiretap信道安全模型的一种编码方式,针对在超奈奎斯特(FTN)条件下传输的极化码,设计了一种无需获知窃听信道信噪比(SNR)的帧间链式加密的安全结构。通过混淆结构将对合法接收端可靠而对非法窃听端阻塞的码元进行扩散,利用物理层主信道和窃听信道的差异,在每一帧中生成主信道可译而窃听信道不可译的密钥序列,对下一帧进行加密,实现安全容量的帧间传输。仿真结果显示,在FTN加速场景和窃听信道SNR相对于主信道波动的前提下,提出的极化码帧间安全结构可在wiretap信道的平均信道退化程度为0 d B时实现信息的安全传输。
基金This work was supported by National Natural Science Foundation of China(No.61961014).
文摘The M-BCJR algorithm based on the Ungerboeck observation model is a recent study to reduce the computational complexity for faster-than-Nyquist(FTN)signaling[1].In this paper,we propose a method that can further reduce the complexity with the approximately same or better bit error rate(BER)performance compared to[1].The information rate(IR)loss for the proposed method is less than 1%compared to the true achievable IR(AIR).The proposed improvement is mainly by introducing channel shortening(CS)before the M-BCJR equalizer.In our proposal,the Ungerboeck M-BCJR algorithm and CS can work together to defeat severe inter-symbol interference(ISI)introduced by FTN signaling.The ISI length for the M-BCJR algorithm with CS is optimized based on the criterion of the IR maximization.For the two cases=0.5 and=0.35,compared to Ungerboeck M-BCJR without CS benchmark[1],the computational complexities of Ungerboeck M-BCJR with CS are reduced by 75%.Moreover,for the case=0.35,the BER performance of Ungerboeck M-BCJR with CS outperforms that of the conventional M-BCJR in[1]at the low signal to noise ratio region.
基金This work was supported by National Natural Science Foundation of China(No.61961014).
文摘Faster-than-Nyquist(FTN)signaling can improve the spectrum efficiency(SE)of the transmission system.In this paper,we propose a coded modulation FTN(CM-FTN)transmission scheme with precoder and channel shortening(CS)optimization to improve bit error rate(BER)performance and reduce the complexity of FTN equalizer.In our proposal,the information rate(IR)or spectral efficiency(SE)is employed and verified as a better performance metric for CM-FTN than the minimum Euclidian distance(MED).The precoder of CM-FTN is optimized for maximizing the IR criterion using the bare-bones particle swarm optimization(BB-PSO)algorithm.Further,a three-carrier CM-FTN system model is used to capture the broadening effect of precoder.Also targeting for the IR maximization,the inter-symbol interference(ISI)length for CS is optimized to reduce the receiver complexity without performance loss.Simulation results demonstrate that our method has a 0.6dB precoding gain compared with the nonprecoding scheme and a maximum of 87.5%of the complexity of FTN equalizer is reduced without BER loss.
