Network Coding (NC) brings correlation between the coded signals from different sources, which makes the system more vulnerable to the decode error at relay. Conventional Cyclic Redundancy Code (CRC) has been implemen...Network Coding (NC) brings correlation between the coded signals from different sources, which makes the system more vulnerable to the decode error at relay. Conventional Cyclic Redundancy Code (CRC) has been implemented for error bit detection. However, its error correction is simply ignored. To fully exploit this feature, this paper proposes a novel joint Log-Likelihood Ratio (LLR) CRC error mitigation for NC two way relay channel. Specific thresholds are designed to estimate the error number of data block and identify those which can be recovered if the number is within the error correction scope of CRC. We examine two modes of the thresholds, one based on the average Bit Error Rate (BER) of source-relay link, while the other based on that of instantaneous one. We provide the full analysis for the Pair-wise Error Probability (PEP) performance of the scheme. A variety of numerical results are presented to reveal the superiority of the proposed scheme to conventional CRC NC under independent Rayleigh fading channels. Moreover, the efficiencies of the proposed thresholds are also validated.展开更多
Gray mapping is a well-known way to improve the performance of regular constellation modulation,but it is challenging to be applied directly for irregular alternative.To address this issue,in this paper,a unified bit-...Gray mapping is a well-known way to improve the performance of regular constellation modulation,but it is challenging to be applied directly for irregular alternative.To address this issue,in this paper,a unified bit-to-symbol mapping method is designed for generalized constellation modulation(i.e.,regular and irregular shaping).The objective of the proposed approach is to minimize the average bit error probability by reducing the hamming distance(HD)of symbols with larger values of pairwise error probability.Simulation results show that the conventional constellation modulation(i.e.,phase shift keying and quadrature amplitude modulation(QAM)with the proposed mapping rule yield the same performance as that of classical gray mapping.Moreover,the recently developed golden angle modulation(GAM)with the proposed mapping method is capable of providing around1 d B gain over the conventional mapping counterpart and offers comparable performance to QAM with Gray mapping.展开更多
为获得非高斯噪声环境衰落信道中正交空时分组码(OSTBC)的性能估计,对OSTBC的成对差错概率(PEP)进行了研究.基于物理统计Middleton Class A噪声模型,通过将非高斯Class A分布变换成条件高斯分布,给出空间依赖时间独立条件下OSTBC系统中...为获得非高斯噪声环境衰落信道中正交空时分组码(OSTBC)的性能估计,对OSTBC的成对差错概率(PEP)进行了研究.基于物理统计Middleton Class A噪声模型,通过将非高斯Class A分布变换成条件高斯分布,给出空间依赖时间独立条件下OSTBC系统中噪声信号的联合概率密度函数.利用矩母函数(MGF)分析法推导Class A噪声环境下最大似然接收机的成对差错概率的上界.对不同衰落信道中系统误符号率(SER)性能的仿真研究表明,在Class A噪声环境下,OSTBC系统性能随噪声脉冲性的增强而下降.展开更多
A non-unitary non-coherent space-time code which is capable of achieving full algebraic diversity is proposed based on full diversity space-time block coding, The error performance is optimized by transforming the non...A non-unitary non-coherent space-time code which is capable of achieving full algebraic diversity is proposed based on full diversity space-time block coding, The error performance is optimized by transforming the non-unitary space-time code into unitary space-time code, By exploiting the desired structure of the proposed code, a grouped generalized likelihood ratio test decoding algorithm is presented to overcome the high complexity of the optimal algorithm, Simulation results show that the proposed code possesses high spectrum efficiency in contrast to the unitary space-time code despite slight loss in the SNR, and besides, the proposed grouped decoding algorithm provides good tradeoff between performance and complexity,展开更多
A family of space-time block codes(STBCs)for systems with even transmit antennas and any number of receive antennas is proposed.The new codeword matrix is constructed by concatenating Alamouti space-time codes to form...A family of space-time block codes(STBCs)for systems with even transmit antennas and any number of receive antennas is proposed.The new codeword matrix is constructed by concatenating Alamouti space-time codes to form a block diagonal matrix,and its dimension is equal to the number of transmit antennas.All Alamouti codes in the same codeword matrix have the same information;thus,full transmit diversity can be achieved over fading channels.To improve the spectral efficiency,multi-level modulations such as multi-quadrature amplitude modulation(M-QAM)are employed.The symbol mapping diversity is then exploited between transmissions of the same information from different antennas to improve the bit error rate(BER)performance.The proposed codes outperform the diagonal algebraic space-time(DAST)codes presented by Damen[Damen et al.IEEE Transactions on Information Theory,2002,48(3):628–636]when they have the same spectral efficiency.Also,they outperform the 1/2-rate codes from complex orthogonal design.Moreover,compared to DAST codes,the proposed codes have a low decoding complexity because we only need to perform linear processing to achieve single-symbol maximum-likelihood(ML)decoding.展开更多
基金Supported by the National 973 Programs (2013CB329104)the National Natural Science Foundations of China (No. 61071090, No. 61171093)+3 种基金the Postgraduate Innovation Programs of Scientific Research of Jiangsu Province (CXZZ11_0388)Jiangsu Province Natural Science Foundation Key Projects (11KJA510001)National Science and Technology Key Projects (2011ZX03005-004-003)Jiangsu 973 Projects (BK2011027)
文摘Network Coding (NC) brings correlation between the coded signals from different sources, which makes the system more vulnerable to the decode error at relay. Conventional Cyclic Redundancy Code (CRC) has been implemented for error bit detection. However, its error correction is simply ignored. To fully exploit this feature, this paper proposes a novel joint Log-Likelihood Ratio (LLR) CRC error mitigation for NC two way relay channel. Specific thresholds are designed to estimate the error number of data block and identify those which can be recovered if the number is within the error correction scope of CRC. We examine two modes of the thresholds, one based on the average Bit Error Rate (BER) of source-relay link, while the other based on that of instantaneous one. We provide the full analysis for the Pair-wise Error Probability (PEP) performance of the scheme. A variety of numerical results are presented to reveal the superiority of the proposed scheme to conventional CRC NC under independent Rayleigh fading channels. Moreover, the efficiencies of the proposed thresholds are also validated.
基金supported in part by the National Key Research and Development Program of China under Grant 2021YFB2900502in part by the National Science Foundation of China under Grant 62001179in part by the Fundamental Research Funds for the Central Universities under Grant 2020kfy XJJS111。
文摘Gray mapping is a well-known way to improve the performance of regular constellation modulation,but it is challenging to be applied directly for irregular alternative.To address this issue,in this paper,a unified bit-to-symbol mapping method is designed for generalized constellation modulation(i.e.,regular and irregular shaping).The objective of the proposed approach is to minimize the average bit error probability by reducing the hamming distance(HD)of symbols with larger values of pairwise error probability.Simulation results show that the conventional constellation modulation(i.e.,phase shift keying and quadrature amplitude modulation(QAM)with the proposed mapping rule yield the same performance as that of classical gray mapping.Moreover,the recently developed golden angle modulation(GAM)with the proposed mapping method is capable of providing around1 d B gain over the conventional mapping counterpart and offers comparable performance to QAM with Gray mapping.
基金Supported by the National Natural Science Foundation of China (Grant No. 60372055)the National Doctoral Foundation of China (Grant No. 20030698027)
文摘A non-unitary non-coherent space-time code which is capable of achieving full algebraic diversity is proposed based on full diversity space-time block coding, The error performance is optimized by transforming the non-unitary space-time code into unitary space-time code, By exploiting the desired structure of the proposed code, a grouped generalized likelihood ratio test decoding algorithm is presented to overcome the high complexity of the optimal algorithm, Simulation results show that the proposed code possesses high spectrum efficiency in contrast to the unitary space-time code despite slight loss in the SNR, and besides, the proposed grouped decoding algorithm provides good tradeoff between performance and complexity,
基金This work was supported in part by the National Basic Research Program of China(Grant No.2007CB310603)the Research Fund of National Mobile Communications Research Laboratory,Southeast University(No.2008A05)+1 种基金the National High Technology Research and Development Program of China(Grant No.2007AA01Z2B1)the National Natural Science Foundation of China(Grant No.60802005).
文摘A family of space-time block codes(STBCs)for systems with even transmit antennas and any number of receive antennas is proposed.The new codeword matrix is constructed by concatenating Alamouti space-time codes to form a block diagonal matrix,and its dimension is equal to the number of transmit antennas.All Alamouti codes in the same codeword matrix have the same information;thus,full transmit diversity can be achieved over fading channels.To improve the spectral efficiency,multi-level modulations such as multi-quadrature amplitude modulation(M-QAM)are employed.The symbol mapping diversity is then exploited between transmissions of the same information from different antennas to improve the bit error rate(BER)performance.The proposed codes outperform the diagonal algebraic space-time(DAST)codes presented by Damen[Damen et al.IEEE Transactions on Information Theory,2002,48(3):628–636]when they have the same spectral efficiency.Also,they outperform the 1/2-rate codes from complex orthogonal design.Moreover,compared to DAST codes,the proposed codes have a low decoding complexity because we only need to perform linear processing to achieve single-symbol maximum-likelihood(ML)decoding.
