中文摘要：

针对正交频分复用（OFDM）系统中存在的高峰均比问题,提出了一种简单而有效的降低峰均比（PA-PR）的联合方法,即将低密度奇偶校验码（LDPC）与传统的限幅（clipping）技术相结合的方法。该方法通过clip-ping技术降低OFDM信号的PAPR,同时结合LDPC码改善clipping技术带来的系统误比特率（BER）恶化与频域滤波降低带外功率辐射。MATLAB仿真结果表明,该方案能够简单而有效地降低PAPR并提高系统的BER性能,以及抑制带外功率辐射,证明了该联合方法的有效性。

英文摘要：

Concerning the problem of high peak-to-average power ratio （PAPR） of orthogonal frequency division multiplexing （OFDM） signal,this paper proposed a simple and effective method that combined traditional clipping technique with low density parity check code （LDPC）.Not only the traditional clipping technique could lower PAPR,but also it could improve the BER performance of the system and reduce the frequency dispersion by LDPC code combining with frequency-domain filtering.MATLAB numerical results show that the proposed solution can reduce the PAPR effectively,improve the BER performance of the system and suppress the out-of-band radiation,which prove the effectiveness of this method.