正交频分复用(Orthogonal freqency division multiplexing,OFDM)技术通过采用多个子载波在不同的子带上传输信息来有效对抗频率选择性衰落。但不同子载波信道质量不同,其中信道质量较差的子载波会产生较大的误码率,从而导致整个系统性...正交频分复用(Orthogonal freqency division multiplexing,OFDM)技术通过采用多个子载波在不同的子带上传输信息来有效对抗频率选择性衰落。但不同子载波信道质量不同,其中信道质量较差的子载波会产生较大的误码率,从而导致整个系统性能下降。将信道质量较差的子载波抑制不用即可解决该问题。本文提出了一种适用于OFDM数据广播系统的联合子载波抑制-机会网络编码方法(Joint subcarriers suppression and opportunistic network coding,JSSONC),即将子载波抑制技术与网络编码(Network coding,NC)技术联合使用。基站抑制信道质量较差的子载波,仅采用信道质量较好的子载波进行数据包的广播与重传。在此基础上,结合机会网络编码,进一步减少重传数据包数量。仿真结果表明,与传统OFDM广播系统相比,本文提出的JSSONC方法降低了每一个数据包平均传输次数(Average transmission times of every data package,ATT-E),从而大大提高了系统传输效率。展开更多
To exploit the effect of modulation schemes on the best relay selection,a novel Jointing Modulation schemes max-min criterion(JM-max-min) is proposed firstly for Two-Way De-Noise-and-Forward(DNF) Opportunistic Relayin...To exploit the effect of modulation schemes on the best relay selection,a novel Jointing Modulation schemes max-min criterion(JM-max-min) is proposed firstly for Two-Way De-Noise-and-Forward(DNF) Opportunistic Relaying systems(TW-DNF-OR) by aiming at minimizing the Pairwise Error Probability(PEP) of Multi-Access(MA) phase which dominates the error per-formance of TW-DNF-OR due to the presence of MA interference.The proposed JM-max-min criterion integrates perfectly the minimum distances of constellations and the relay links gains.Then,with the proposed JM-max-min criterion,we analyze the Symbol Error Probabilities(SEPs) of MA phase and BroadCast(BC) phase by using the approximated mathematics analysis,and present the corresponding closed-form expressions to SEPs.The numerical analysis shows,for a given modulations combination at both sources,the TW-DNF-OR systems with the proposed JM-max-min criterion outperform the one with the conventional max-min criterion.展开更多
文摘正交频分复用(Orthogonal freqency division multiplexing,OFDM)技术通过采用多个子载波在不同的子带上传输信息来有效对抗频率选择性衰落。但不同子载波信道质量不同,其中信道质量较差的子载波会产生较大的误码率,从而导致整个系统性能下降。将信道质量较差的子载波抑制不用即可解决该问题。本文提出了一种适用于OFDM数据广播系统的联合子载波抑制-机会网络编码方法(Joint subcarriers suppression and opportunistic network coding,JSSONC),即将子载波抑制技术与网络编码(Network coding,NC)技术联合使用。基站抑制信道质量较差的子载波,仅采用信道质量较好的子载波进行数据包的广播与重传。在此基础上,结合机会网络编码,进一步减少重传数据包数量。仿真结果表明,与传统OFDM广播系统相比,本文提出的JSSONC方法降低了每一个数据包平均传输次数(Average transmission times of every data package,ATT-E),从而大大提高了系统传输效率。
基金Supported by the National Natural Science Foundations of China (No. 61071090,No. 61171093)the Postgraduate Innovation Programs of Scientific Research of Jiangsu Province (CX10B-184Z,CXZZ11_0388)the Project 11KJA510001 and PAPD
文摘To exploit the effect of modulation schemes on the best relay selection,a novel Jointing Modulation schemes max-min criterion(JM-max-min) is proposed firstly for Two-Way De-Noise-and-Forward(DNF) Opportunistic Relaying systems(TW-DNF-OR) by aiming at minimizing the Pairwise Error Probability(PEP) of Multi-Access(MA) phase which dominates the error per-formance of TW-DNF-OR due to the presence of MA interference.The proposed JM-max-min criterion integrates perfectly the minimum distances of constellations and the relay links gains.Then,with the proposed JM-max-min criterion,we analyze the Symbol Error Probabilities(SEPs) of MA phase and BroadCast(BC) phase by using the approximated mathematics analysis,and present the corresponding closed-form expressions to SEPs.The numerical analysis shows,for a given modulations combination at both sources,the TW-DNF-OR systems with the proposed JM-max-min criterion outperform the one with the conventional max-min criterion.
