Orthogonal frequency division multiplexing(OFDM) is an attractive technology to provide immense improvement in wireless transmission capacity but high peak-to-average power ratio(PAPR) is a major drawback of OFDM syst...Orthogonal frequency division multiplexing(OFDM) is an attractive technology to provide immense improvement in wireless transmission capacity but high peak-to-average power ratio(PAPR) is a major drawback of OFDM system.Selected mapping(SLM) scheme has good performance for PAPR reduction.It requires the transmitting data to be multiplied by random phase sequences.However,the sequences are pseudo-random which will decrease the method effectiveness.Exhaustive entropy is introduced in this paper which can identify the strength of random phase sequences property.Then an exhaustive entropy based on SLM method is proposed.The scheme improves the effectiveness of random phase sequences by selecting the larger exhaustive entropy of them.The simulation results show that the PAPR reduction performance is better than that of conventional SLM through this method.展开更多
正交频分复用技术(OFDM,Orthogonal Frequency Division Multiplexing)是一种有效的并行多载波传输方案,然而,OFDM技术存在一个主要缺点,即发送信号存在较高的峰值平均功率比(PAPR,Peak-to-Average Power Ratio)。研究表明高带宽效率的...正交频分复用技术(OFDM,Orthogonal Frequency Division Multiplexing)是一种有效的并行多载波传输方案,然而,OFDM技术存在一个主要缺点,即发送信号存在较高的峰值平均功率比(PAPR,Peak-to-Average Power Ratio)。研究表明高带宽效率的限幅类技术着眼于直接降低OFDM信号的峰均比,而幅度和相位预失真方法则是从放大器的角度出发,对放大器进行预失真处理,增大功率放大器的线性范围。这里提出将限幅类技术和预失真处理进行联合实现,从而在系统PAPR减小、失真补偿和误码率之间取得较好的折中。展开更多
在正交频分复用(orthogonal frequency division multiplexing,OFDM)系统中,若各支路在同一相位上叠加会带来幅值的叠加从而产生大的峰均比(peak to average power ratio,PAPR)。选择性映射方法是一种有效降低正交频分复用系统峰均比的...在正交频分复用(orthogonal frequency division multiplexing,OFDM)系统中,若各支路在同一相位上叠加会带来幅值的叠加从而产生大的峰均比(peak to average power ratio,PAPR)。选择性映射方法是一种有效降低正交频分复用系统峰均比的方法,对传统的选择性映射方法做了改进,提出了一种新的循环反馈选择性映射算法。在该算法中,采用了若干ZC(Zandoff-Chu)序列作为初始的相位旋转矢量,对于传统选择性映射方法中的每个子块不再固定其相位矢量,而是根据峰均比比较结果的反馈做出相应的相位矢量调整。通过在AWGN(additive white Gaussian noise)信道环境进行仿真,进一步分析加入循环反馈选择性映射算法的OFDM系统和传统OFDM系统。仿真结果表明,提出的加入循环反馈选择性映射算法可有效地降低峰均比并改善接收端的比特误码率(bit error rate,BER)性能。展开更多
基金Sponsored by the National Natural Science Foundation of China (Grant No. 61101126)the Postdoctoral Science Foundation of China (Grant No.2011M500664)
文摘Orthogonal frequency division multiplexing(OFDM) is an attractive technology to provide immense improvement in wireless transmission capacity but high peak-to-average power ratio(PAPR) is a major drawback of OFDM system.Selected mapping(SLM) scheme has good performance for PAPR reduction.It requires the transmitting data to be multiplied by random phase sequences.However,the sequences are pseudo-random which will decrease the method effectiveness.Exhaustive entropy is introduced in this paper which can identify the strength of random phase sequences property.Then an exhaustive entropy based on SLM method is proposed.The scheme improves the effectiveness of random phase sequences by selecting the larger exhaustive entropy of them.The simulation results show that the PAPR reduction performance is better than that of conventional SLM through this method.
文摘正交频分复用技术(OFDM,Orthogonal Frequency Division Multiplexing)是一种有效的并行多载波传输方案,然而,OFDM技术存在一个主要缺点,即发送信号存在较高的峰值平均功率比(PAPR,Peak-to-Average Power Ratio)。研究表明高带宽效率的限幅类技术着眼于直接降低OFDM信号的峰均比,而幅度和相位预失真方法则是从放大器的角度出发,对放大器进行预失真处理,增大功率放大器的线性范围。这里提出将限幅类技术和预失真处理进行联合实现,从而在系统PAPR减小、失真补偿和误码率之间取得较好的折中。
文摘在正交频分复用(orthogonal frequency division multiplexing,OFDM)系统中,若各支路在同一相位上叠加会带来幅值的叠加从而产生大的峰均比(peak to average power ratio,PAPR)。选择性映射方法是一种有效降低正交频分复用系统峰均比的方法,对传统的选择性映射方法做了改进,提出了一种新的循环反馈选择性映射算法。在该算法中,采用了若干ZC(Zandoff-Chu)序列作为初始的相位旋转矢量,对于传统选择性映射方法中的每个子块不再固定其相位矢量,而是根据峰均比比较结果的反馈做出相应的相位矢量调整。通过在AWGN(additive white Gaussian noise)信道环境进行仿真,进一步分析加入循环反馈选择性映射算法的OFDM系统和传统OFDM系统。仿真结果表明,提出的加入循环反馈选择性映射算法可有效地降低峰均比并改善接收端的比特误码率(bit error rate,BER)性能。
