摘要
正交频分复用(OFDM)技术是一种多载波调制技术,其频谱效率高,并且在对抗多径衰落特别是频率选择性信道方面有着巨大优势。然而,由于OFDM信号具有高峰均功率比,因此在通过高功率放大器(HPA)的时候,会产生非线性失真,从而严重影响系统误码率性能。提出一种新的结合压扩和预失真的信号处理算法,通过压扩降低峰值功率,降低OFDM信号超过HPA饱和点部分造成的失真,并通过预失真技术,降低HPA饱和点以内失真,从而大大降低了HPA对OFDM信号误码率造成的影响,提升了系统的误码率性能。仿真结果分析表明,同传统的压扩算法和预失真算法相比较,所提的算法具有更好的误码率性能。
Orthogonal Frequency Division Multiplexing （OFDM） is a multi-carrier modulation （MCM） technique, which offers a considerable high spectral efficiency, multipath delay spread tolerance, and immunity to the frequency selective fading channels. However, the memory-less nonlinear distortion due to high PAPR of the OFDM signals will be introduced into the communication systems, when the OFDM signals is inputted to the high power amplifier （HPA）, and the bit error rate performance will be decreased. A novel compandingjoint predistortion scheme was proposed. The companding technique was employed to reduce the peak power of the signals to reduce the distortion above the the saturation region, and the predistortion technique was employed to reduce the distortion within the the saturation region. Therefore, the nonlinear distortion caused by the HPA was reduced, and the BER performance was greatly improved. Compared with the traditional companding scheme and the predistortion scheme, the proposed method can provide better BER performance.
出处
《系统仿真学报》
CAS
CSCD
北大核心
2014年第2期289-293,共5页
Journal of System Simulation
基金
湖北理工学院自然科学基金(11yjz20Q)
