针对传统峰均功率比(PAPR)降低方法存在带内、带外畸变干扰问题,提出了一种变因子迭代峰值功率降低方法.首先,采用并行噪声成型滤波器降低消波引起的带外干扰,建立了基于峰值瞬时包络和迭代次数的时变尺寸因子,自适应抑制剩余带外噪声;然后,采用噪声对消的方法抑制峰值过载引起的带内再生干扰,并通过多步迭代的方式进行平滑处理.仿真结果表明:所提方法两步迭代后即可达到5.5dB的PAPR降低,有效改善了信号包络时变对功率放大器非线性的影响,保持了较好的星座特征,临道干扰平均降低了10dB.
A variable factor iterative peak power reduction method was proposed for the problem that the traditional peak to average power ratio (PAPR)reduction method exists in-band and out-of-band distortion interference phenomenon.Firstly,the parallel noise shaping filter was used to reduce out-of-band interference which caused by clipping.The time-varying scaling factor was established to sup-press the residual out-of-band noise adaptively,which based on the instantaneous envelope peak and the number of iterations.Then,the clipping noise cancellation method was used to suppress in-band peak re-growth interference caused by peak overload.The multi-step iterative method was used to smooth the suppressed signal.Simulation results show that the proposed method can achieve 5 .5 dB PAPR reduction after two-step iterative,and improve the effect of the signal envelope time-varying to power amplifier.And the method maintains a good constellation characteristics and improves the adj a-cent channel interference to 1 0 dB.