Enhanced Nonlinear Companding Scheme for Reducing PAPR of OFDM Systems
Enhanced Nonlinear Companding Scheme for Reducing PAPR of OFDM Systems
复制标题
用于降低 OFDM 系统 PAPR 的增强型非线性压扩方案
DOI：
10.1109/jsyst.2018.2851847
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发表时间：
2019
影响因子：
4.4
通讯作者：
Adebisi B
中科院分区：
文献类型：
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作者：
Adebisi B
提出了一种降低正交频分复用系统峰均功率比的新压扩方案。它从语音信号处理出发，类似于最早的μ定律压扩(MC)模型。该方案将OFDM信号的幅度压缩(压缩和扩展)到最大1V，除了显著降低PAPR外，还能够起到限幅器的作用，从而降低了系统的复杂性，并将OFDM符号的幅度限制在一个单位的最大电压，这是其他压扩PAPR技术所不存在的。在频域均衡的频率选择性衰落信道中，利用最小均方误差(MMSE)最小化噪声开销，该技术在弱衰落和严重衰落条件下的性能优于其他四种压扩方案。最后，我们证明了在接收端使用压扩降低PAPR可以省去相应的解压缩方案，因为它放大了失真噪声，从而降低了误码率性能，增加了接收机的复杂度。我们研究了所提出的方案的带外干扰，并表明它的性能比其他现有技术高达5分贝。
A new companding scheme for reducing the peak-to-average power ratio (PAPR) of orthogonal frequency-division multiplexing (OFDM) systems is proposed in this study. It proceeds from speech signal processing similar to the earliest μ-law companding (MC) model. The proposed scheme compands (compresses and expands) the amplitudes of OFDM signals to a maximum of 1 V. Besides significantly reducing the PAPR, the proposed technique is also able to function as a limiter, thus reducing the system complexity and limiting the amplitudes of OFDM symbols to a unity maximum voltage, which does not exist in other companding PAPR techniques. Over frequency-selective fading channels with frequency domain equalization and using minimum mean square error (MMSE) to minimize the noise overhead, the proposed technique outperforms four other companding schemes over light and severe fading conditions. Finally, we demonstrate that PAPR reduction using companding can dispense with corresponding decompanding scheme at the receiver as it amplifies the distortion noise, thereby reducing the bit error ratio performance and increasing the receiver complexity. We investigate the out-of-band interference of the proposed scheme and also show that it outperforms the other existing techniques by up to 5 dB.