空间调制(Spatial Modulation, SM)技术和OFDM多模子载波索引调制(OFDMMulti-Mode Index Modulation, MM-OFDM-IM)技术分别在能量效率(Energy Efficiency,EE)和频谱效率(Spectral Efficiency,SE)上有着很大的优势。多维度索引调制技术...空间调制(Spatial Modulation, SM)技术和OFDM多模子载波索引调制(OFDMMulti-Mode Index Modulation, MM-OFDM-IM)技术分别在能量效率(Energy Efficiency,EE)和频谱效率(Spectral Efficiency,SE)上有着很大的优势。多维度索引调制技术相结合能够应用多种物理资源,应对无线通信系统对数据传输和系统容量的高需求,由此将SM与MMOFDM-IM系统灵活结合,构建基于空频结合的多模复合索引调制(OFDM-Multiple-Mode Space Frequency Composite Index Modulation,MM-OFDM-SFCIM)系统,保留传统子载波索引调制技术中的静默子载波,拓展新的复合系数维度,提高系统的SE和EE。针对系统的复杂特性,提出了基于符号能量及对数似然的联合检测算法(REML based on symbolic Energy and LLR,EL-REML)。仿真结果表明,MM-OFDM-SFCIM系统比传统的空频结合系统在SE上提高了约30%,并且MM-DFDM-SPCIM系统中提出的EL-REML算法比LLR算法在误码率上提高了3~4 dB,相比传统的ML算法,其计算复杂度更低。展开更多
timizing the formula, the energy for every bit of the codeword is optimized to achieve the minimum BER at high SNR region. At last, an adjustable parameter is employed to compensate the degrada- tions of BER at low an...timizing the formula, the energy for every bit of the codeword is optimized to achieve the minimum BER at high SNR region. At last, an adjustable parameter is employed to compensate the degrada- tions of BER at low and moderate SNR regions. Case studies indicate that the improvements of BER for turbo codes with short frame size are significant at a wide range of SNR展开更多
There are considerable literatures on the Bit Error Rate(BER)evaluation of DifferentialDetection of Gaussian Minimum Shift Keying(DDGMSK)system using Decision Feedback(DF),butmost of them give the performance based on...There are considerable literatures on the Bit Error Rate(BER)evaluation of DifferentialDetection of Gaussian Minimum Shift Keying(DDGMSK)system using Decision Feedback(DF),butmost of them give the performance based on the Monte Carlo Error Counting(MCEC)technique.Fromthe probability distribution of the phase angle between two vectors perturbed by Gaussian noises,theformulae of BER are derived for the performance analysis of DDGMSK system with DF in this letter.Considering the m-bit dock-tailed sequence,the new formulae of Gaussian Minimum Shift Keying(GMSK)modulated phase and the Time-Varying Signal to Noise Ratio(TVSNR)of the demodulatedsignal are presented,and it is proved that the relationship between the TVSNR of the demodulatedsignal and the size of eye opening is not inevitable.Simulation results show that the theoretical in-vestigation gives analogous results with the MCEC technique.The formulae presented are useful for theperformance analysis of systems using GMSK as modulating and demodulating method,for instance,the analysis of synchronous performance of frequency-hopping communication system.展开更多
文摘空间调制(Spatial Modulation, SM)技术和OFDM多模子载波索引调制(OFDMMulti-Mode Index Modulation, MM-OFDM-IM)技术分别在能量效率(Energy Efficiency,EE)和频谱效率(Spectral Efficiency,SE)上有着很大的优势。多维度索引调制技术相结合能够应用多种物理资源,应对无线通信系统对数据传输和系统容量的高需求,由此将SM与MMOFDM-IM系统灵活结合,构建基于空频结合的多模复合索引调制(OFDM-Multiple-Mode Space Frequency Composite Index Modulation,MM-OFDM-SFCIM)系统,保留传统子载波索引调制技术中的静默子载波,拓展新的复合系数维度,提高系统的SE和EE。针对系统的复杂特性,提出了基于符号能量及对数似然的联合检测算法(REML based on symbolic Energy and LLR,EL-REML)。仿真结果表明,MM-OFDM-SFCIM系统比传统的空频结合系统在SE上提高了约30%,并且MM-DFDM-SPCIM系统中提出的EL-REML算法比LLR算法在误码率上提高了3~4 dB,相比传统的ML算法,其计算复杂度更低。
基金Supported by the National High Technology Research and Development Programme of China(No.2014AA01A705)the National Natural Science Foundation of China(U1204607)
文摘timizing the formula, the energy for every bit of the codeword is optimized to achieve the minimum BER at high SNR region. At last, an adjustable parameter is employed to compensate the degrada- tions of BER at low and moderate SNR regions. Case studies indicate that the improvements of BER for turbo codes with short frame size are significant at a wide range of SNR
基金the National Natural Science Foundation of China(No.60132030,60572147)the 111 Project(B08033).
文摘There are considerable literatures on the Bit Error Rate(BER)evaluation of DifferentialDetection of Gaussian Minimum Shift Keying(DDGMSK)system using Decision Feedback(DF),butmost of them give the performance based on the Monte Carlo Error Counting(MCEC)technique.Fromthe probability distribution of the phase angle between two vectors perturbed by Gaussian noises,theformulae of BER are derived for the performance analysis of DDGMSK system with DF in this letter.Considering the m-bit dock-tailed sequence,the new formulae of Gaussian Minimum Shift Keying(GMSK)modulated phase and the Time-Varying Signal to Noise Ratio(TVSNR)of the demodulatedsignal are presented,and it is proved that the relationship between the TVSNR of the demodulatedsignal and the size of eye opening is not inevitable.Simulation results show that the theoretical in-vestigation gives analogous results with the MCEC technique.The formulae presented are useful for theperformance analysis of systems using GMSK as modulating and demodulating method,for instance,the analysis of synchronous performance of frequency-hopping communication system.
