为了降低正交频分复用(orthogonal frequency division multiplexing,OFDM)系统中传统选择性映射(conventional selected mapping,CSLM)算法的计算复杂度,提高系统的频谱利用效率,提出了一种基于盲检测的低复杂度分块选择性映射(block s...为了降低正交频分复用(orthogonal frequency division multiplexing,OFDM)系统中传统选择性映射(conventional selected mapping,CSLM)算法的计算复杂度,提高系统的频谱利用效率,提出了一种基于盲检测的低复杂度分块选择性映射(block selected mapping,BSLM)算法,发送端利用逆快速傅里叶反变换(inverse fast fourier transform,IFFT)性质仅需少量低维IFFT运算即可获得较多的备选序列,接收端采用低复杂度的盲检测方式。仿真分析了所提算法的峰均功率比(peak to average power ratio,PAPR)、立方度量(cubic metric,CM)和误比特率(bit error rate,BER)性能。结果表明,所提算法不仅明显降低了计算复杂度,而且有效抑制了OFDM信号的PAPR和CM,获得与已知边带信息的CSLM算法相近的BER性能。展开更多
To meet long term evolution-advanced （LTE-A） requirements of wider bandwidth and maintain backwards compatibility with LTE release 8 （Rel-8） simultaneously, carrier aggregation has been agreed by the third generat...To meet long term evolution-advanced （LTE-A） requirements of wider bandwidth and maintain backwards compatibility with LTE release 8 （Rel-8） simultaneously, carrier aggregation has been agreed by the third generation partnership project （3GPP）. High cubic metric （CM） values and peak-to-average power ratio （PAPR） of aggregated component carriers （CCs） exists as an unpleasant issue for both uplink and downlink （DL） transmission. For DL transmission, to use distinct cell ID per DL CC to generate DL reference signal （RS） sequence can mitigate this problem but will cause some other issues on the corresponding uplink carrier. This article proposes two approaches to solve the problem of high CM/PAPR by introducing new variables to change the cell-specific DL RS sequence. In both methods, same cell identifier （cell ID） is allocated to all DL CCs. Simulation results show the performance improvements and prove the effectivity of our proposed approaches.展开更多
文摘使用数值仿真和电路实验的方法,对QPSK(quadrature phase shift keying)和OQPSK(off-set quadrature phase shift keying)调制信号通过功率放大器后的频谱扩散问题进行了探讨,对比了2种调制信号的raw-cm(raw cubic metric)参数和PAPR(peak to average power ratio)参数的变化.针对三阶非线性放大器模型的计算机仿真结果表明:当OQPSK调制信号的PAPR参数比QPSK调制信号的PAPR参数改善0.58dB时,其临道功率谱扩散指标却恶化了0.08dB;实验结果也证明,在信号的PAPR参数指标获得改善的同时,并不意味着信号通过功率放大器之后的频谱扩散性能一定会获得改善,在所举案例的情况下甚至是恶化的.另一方面,仿真和实验均证实,在信号的raw-cm参数获得改善时,信号通过放大器后的频谱扩散性能也获得了相应的改善.
文摘为了降低正交频分复用(orthogonal frequency division multiplexing,OFDM)系统中传统选择性映射(conventional selected mapping,CSLM)算法的计算复杂度,提高系统的频谱利用效率,提出了一种基于盲检测的低复杂度分块选择性映射(block selected mapping,BSLM)算法,发送端利用逆快速傅里叶反变换(inverse fast fourier transform,IFFT)性质仅需少量低维IFFT运算即可获得较多的备选序列,接收端采用低复杂度的盲检测方式。仿真分析了所提算法的峰均功率比(peak to average power ratio,PAPR)、立方度量(cubic metric,CM)和误比特率(bit error rate,BER)性能。结果表明,所提算法不仅明显降低了计算复杂度,而且有效抑制了OFDM信号的PAPR和CM,获得与已知边带信息的CSLM算法相近的BER性能。
基金supported by the National Basic Research Program of China (2007CB310607)the National Natural Science Foundation of China (60772062)+1 种基金the National Projects (2009ZX03007-004, 2009ZX03003-002)the Hi-Tech Research and Development Program of China (2009AA011302)
文摘To meet long term evolution-advanced （LTE-A） requirements of wider bandwidth and maintain backwards compatibility with LTE release 8 （Rel-8） simultaneously, carrier aggregation has been agreed by the third generation partnership project （3GPP）. High cubic metric （CM） values and peak-to-average power ratio （PAPR） of aggregated component carriers （CCs） exists as an unpleasant issue for both uplink and downlink （DL） transmission. For DL transmission, to use distinct cell ID per DL CC to generate DL reference signal （RS） sequence can mitigate this problem but will cause some other issues on the corresponding uplink carrier. This article proposes two approaches to solve the problem of high CM/PAPR by introducing new variables to change the cell-specific DL RS sequence. In both methods, same cell identifier （cell ID） is allocated to all DL CCs. Simulation results show the performance improvements and prove the effectivity of our proposed approaches.
