双模离散傅里叶变换–扩展正交频分复用(discrete fourier transform–spreading-orthogonal frequency division multiplexing-discrete multi,DFT-S-OFDM-DM)系统虽然拥有优秀的峰均功率比(peak to average power ratio,PAPR)、信道...双模离散傅里叶变换–扩展正交频分复用(discrete fourier transform–spreading-orthogonal frequency division multiplexing-discrete multi,DFT-S-OFDM-DM)系统虽然拥有优秀的峰均功率比(peak to average power ratio,PAPR)、信道适应能力以及低复杂度,但此系统在频谱效率(spectral efficiency,SE)表现上并不理想,系统中的离散傅里叶变换(discrete fourier transform,DFT)扩展和双模调制都有一定的改进空间。针对此系统,提出新的多维索引离散傅里叶变换-扩展正交频分复用(discrete fourier transform-spreading-orthogonal frequency division multiplexing-multi dimension index,DFT-S-OFDM-MDI)系统,新系统将DFT扩展改为DFT索引扩展,增加新的子载波索引位,增加双模调制搭配种类,提升双模索引位宽,进而提升系统SE。本文还为新系统配置6种双模星座图,并与预编码增益矩阵搭配,提升系统误码率(bit error ratio,BER)性能。仿真结果表明,系统具有优秀的SE和BER性能,优于多种传统方案。展开更多
为了提升DFT-S-OFDM系统在瑞利信道下的传输性能,采用位交织编码调制迭代译码方案(BICM-ID)、旋转映射(R-QAM)和Turbo码等技术,设计了基于Turbo-BICM-ID的DFT-S-OFDM系统。给出了系统原理框图,对编码调制系统的解调译码迭代算法进行了推...为了提升DFT-S-OFDM系统在瑞利信道下的传输性能,采用位交织编码调制迭代译码方案(BICM-ID)、旋转映射(R-QAM)和Turbo码等技术,设计了基于Turbo-BICM-ID的DFT-S-OFDM系统。给出了系统原理框图,对编码调制系统的解调译码迭代算法进行了推导,对系统进行了Matlab仿真验证。仿真结果表明,与传统的卷积码设计方案相比,该设计方案在误码率为10-5时,可以获得5.7 d B的增益改善,同时可以获得更低的错误平层,有效地改善了DFT-S-OFDM系统在瑞利信道下的性能。展开更多
Discrete Fourier transform spread orthogonal frequency division multiplexing （DFT-S-OFDM） based single carrier-frequency division multiple access （SC-FDMA） is accepted as the uplink transmission scheme by the 3GPP...Discrete Fourier transform spread orthogonal frequency division multiplexing （DFT-S-OFDM） based single carrier-frequency division multiple access （SC-FDMA） is accepted as the uplink transmission scheme by the 3GPP-Iong term evolution standardization organization. In this paper, the effects of carrier frequency offset （CFO） on DFT-S-OFDM system are analyzed for both single user and multiple user accessing scenarios. According to the analysis, the CFO results in the attenuation, linear phase rotation, inter-symbol interference （ISI） and inter-sub-carrier interference （ICI） on the demodulated symbols of each desired user, and the multi-user interference （MUI） among upiink users. The theoretical values of ISI, ICl, and signal to interference ratio （SIR） are presented for the DFT-S-OFDM system with full and partial bandwidth detection respectively. A phase compensation method is proposed to reduce the effect of linear phase rotation on the demodulated symbols. Finally, the analytical values are verified by the simulation results.展开更多
文摘双模离散傅里叶变换–扩展正交频分复用(discrete fourier transform–spreading-orthogonal frequency division multiplexing-discrete multi,DFT-S-OFDM-DM)系统虽然拥有优秀的峰均功率比(peak to average power ratio,PAPR)、信道适应能力以及低复杂度,但此系统在频谱效率(spectral efficiency,SE)表现上并不理想,系统中的离散傅里叶变换(discrete fourier transform,DFT)扩展和双模调制都有一定的改进空间。针对此系统,提出新的多维索引离散傅里叶变换-扩展正交频分复用(discrete fourier transform-spreading-orthogonal frequency division multiplexing-multi dimension index,DFT-S-OFDM-MDI)系统,新系统将DFT扩展改为DFT索引扩展,增加新的子载波索引位,增加双模调制搭配种类,提升双模索引位宽,进而提升系统SE。本文还为新系统配置6种双模星座图,并与预编码增益矩阵搭配,提升系统误码率(bit error ratio,BER)性能。仿真结果表明,系统具有优秀的SE和BER性能,优于多种传统方案。
文摘为了提升DFT-S-OFDM系统在瑞利信道下的传输性能,采用位交织编码调制迭代译码方案(BICM-ID)、旋转映射(R-QAM)和Turbo码等技术,设计了基于Turbo-BICM-ID的DFT-S-OFDM系统。给出了系统原理框图,对编码调制系统的解调译码迭代算法进行了推导,对系统进行了Matlab仿真验证。仿真结果表明,与传统的卷积码设计方案相比,该设计方案在误码率为10-5时,可以获得5.7 d B的增益改善,同时可以获得更低的错误平层,有效地改善了DFT-S-OFDM系统在瑞利信道下的性能。
基金Supported by the National High-Tech Research & Development Program of China (Grant No. 2006AA01Z280)the National Key Projectof China during the 11th Five-Year Plan Period (Grant No. 2009ZX03003-006-03)
文摘Discrete Fourier transform spread orthogonal frequency division multiplexing （DFT-S-OFDM） based single carrier-frequency division multiple access （SC-FDMA） is accepted as the uplink transmission scheme by the 3GPP-Iong term evolution standardization organization. In this paper, the effects of carrier frequency offset （CFO） on DFT-S-OFDM system are analyzed for both single user and multiple user accessing scenarios. According to the analysis, the CFO results in the attenuation, linear phase rotation, inter-symbol interference （ISI） and inter-sub-carrier interference （ICI） on the demodulated symbols of each desired user, and the multi-user interference （MUI） among upiink users. The theoretical values of ISI, ICl, and signal to interference ratio （SIR） are presented for the DFT-S-OFDM system with full and partial bandwidth detection respectively. A phase compensation method is proposed to reduce the effect of linear phase rotation on the demodulated symbols. Finally, the analytical values are verified by the simulation results.
