Design of Low PAPR Fundamental Modulation Waveform for Transform Domain Communication System
Design of Low PAPR Fundamental Modulation Waveform for Transform Domain Communication System
复制标题
变换域通信系统低PAPR基波调制波形设计
DOI：
10.1007/s11277-012-0932-8
复制
发表时间：
2013-08-01
影响因子：
2.2
通讯作者：
Li, Shaoqian
中科院分区：
文献类型：
--
作者：
Hu, Su;Wu, Gang;Li, Shaoqian
为了充分利用无线电环境中的白色空间频谱，提出了一种变换域通信系统（transform domain communication system，TDCS），利用频谱置零和频域扩频技术实现覆盖认知无线电通信系统。与OFDM系统类似，TDCS系统在大功率放大器的存在下，仍然存在峰均功率比（PAPR）高峰问题。本文提出了一种无失真的降低TDCS峰均比的方法，即削波相位替换（CPR）。在此方法之后，限幅噪声脏相位矢量被从相同相位映射空间中选择的适当替换所替换，以避免系统性能下降。针对穷举搜索算法计算复杂度高的问题，提出了一种通过迭代降低峰均比和相位替换的有效实现CPR方法。此外，一些考虑实际应用中，如不完善的频谱感知和相位抽头的数量，被认为是。分析和仿真结果表明，无失真CPR峰均比降低方法是一个较好的候选TDCS在单用户和多用户的情况下。
To utilize white space spectrum in radio environment, transform domain communication system (TDCS) has been proposed to realize an overlay cognitive radio communication system by using spectrum bin nulling and frequency domain spreading. Being similar to OFDM systems, TDCSs still suffer from the problem of high peak to average power ratio (PAPR) in present of high power amplifier. In this paper, a distortionless PAPR reduction method is proposed for TDCS, namely clipping and phase replacement (CPR). Following this method, the clipping noise-dirty phase vector is replaced by an appropriate replacement, which is selected from the identical phase mapping space to avoid systematic performance degradation. Owing to the high computational complexity from exhaust search, an efficient implementation of CPR method is proposed through the iterative PAPR reduction and phase replacement. Moreover, some considerations for practical applications, such as imperfect spectrum sensing and the number of phase taps, are considered. Analytic and simulation results demonstrate that the distortionless CPR PAPR reduction method is a preferable candidate for TDCSs in both the single-user and multi-user scenarios.