高考问答苹果怎么看数据线认证:英文普通翻译。公式不用翻译，翻译快的话送分
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In this section we focus more closely on the PAPR reduction techniques for multicarrier transmission with some examples.
AMPLITUDE CLIPPING AND FILTERING
The simplest technique for PAPR reduction might be amplitude clipping [10]. Amplitude clipping limits the peak envelope of the input signal to a predetermined value or otherwise passes the input signal through unperturbed [42],that is,(7)where f(x) is the phase of x. The distortion caused by amplitude clipping can be viewed as another source of noise. The noise caused by
amplitude clipping falls both in-band and outof-band. In-band distortion cannot be reduced by filtering and results in an error performance degradation, while out-of-band radiation reduces spectral efficiency. Filtering after clipping can reduce out-of-band radiation but may also cause some peak regrowth so that the signal after clipping and filtering will exceed the
clipping level at some points. To reduce overall peak regrowth, a repeated clipping-and-filtering operation can be used [11,12]. Generally,repeated clipping-and-filtering takes many iterations
to reach a desired amplitude level. When repeated clipping-and-filtering is used in conjunction with other PAPR reduction techniques described below, the deleterious effects may be
significantly reduced.There are a few techniques proposed to mitigate the harmful effects of the amplitude clipping.In [43] a method to iteratively reconstructthe signal before clipping is proposed. This method is based on the fact that the effect of
clipping noise is mitigated when decisions are made in the frequency domain. When the decisions are converted back to the time domain, the signal is recovered somewhat from the harmful
effects of clipping, although this may not be perfect.An improvement can be made by repeating the above procedures.Another way to compensate for the performance degradation from clipping is to reconstruct the clipped samples based on the other samples in the oversampled signals.In [44] oversampled signal reconstruction is used to compensate for signal-to-noise ratio (SNR)degradation due to clipping for low values of clipping threshold. In [45] iterative estimation
and cancellation of clipping noise is proposed.This technique exploits the fact that clipping noise is generated by a known process that can be recreated at the receiver and subsequently
removed.
AMPLITUDE CLIPPING AND FILTERING
The simplest technique for PAPR reduction might be amplitude clipping [10]. Amplitude clipping limits the peak envelope of the input signal to a predetermined value or otherwise passes the input signal through unperturbed [42],that is,(7)where f(x) is the phase of x. The distortion caused by amplitude clipping can be viewed as another source of noise. The noise caused by
amplitude clipping falls both in-band and outof-band. In-band distortion cannot be reduced by filtering and results in an error performance degradation, while out-of-band radiation reduces spectral efficiency. Filtering after clipping can reduce out-of-band radiation but may also cause some peak regrowth so that the signal after clipping and filtering will exceed the
clipping level at some points. To reduce overall peak regrowth, a repeated clipping-and-filtering operation can be used [11,12]. Generally,repeated clipping-and-filtering takes many iterations
to reach a desired amplitude level. When repeated clipping-and-filtering is used in conjunction with other PAPR reduction techniques described below, the deleterious effects may be
significantly reduced.There are a few techniques proposed to mitigate the harmful effects of the amplitude clipping.In [43] a method to iteratively reconstructthe signal before clipping is proposed. This method is based on the fact that the effect of
clipping noise is mitigated when decisions are made in the frequency domain. When the decisions are converted back to the time domain, the signal is recovered somewhat from the harmful
effects of clipping, although this may not be perfect.An improvement can be made by repeating the above procedures.Another way to compensate for the performance degradation from clipping is to reconstruct the clipped samples based on the other samples in the oversampled signals.In [44] oversampled signal reconstruction is used to compensate for signal-to-noise ratio (SNR)degradation due to clipping for low values of clipping threshold. In [45] iterative estimation
and cancellation of clipping noise is proposed.This technique exploits the fact that clipping noise is generated by a known process that can be recreated at the receiver and subsequently
removed.
在这一节,我们更加注重技术的PAPR减少传染multicarrier一些例子. 广式过滤 最简单的方法可以减少幅度降低PAPR10. 范围广式信封高峰的信号输入到预定值或通过输入信号通过占用42,(7),F(X)是X阶段 造成扭曲的幅度降低,可以看作是一个噪音源. 因噪音 无论是广式的波段,outof波段. 在波段不能减少扭曲,导致错误的过滤性能恶化,出波段辐射光谱效率降低. 过滤后可以降低存出辐射污染,但也可能带来一些繁忙再生,使信号降低,过滤后,将超出 水平式几点. 降低整体峰值再生、重复式中可以使用过滤操作[女子]. 一般地说,多次降低中有许多重复过滤 工会达成预期的水平.当重覆的剪报和过滤被使用与其它PAPR 减少技术一道下述, 有害作用也许极大是reduced.There 是几个技术提议重申缓和高度clipping.In [ 43 的] 有害的作用方法对reconstructthe 信号在剪报提议之前。这个方法根据事实截去噪声的作用被缓和当决定被做出在频率领域。当决定被转换回到时间界域, 信号从剪报的有害的作用恢复有些, 虽然这不能是perfect.An 改善可能由重覆做上述procedures.Another 方式补尝性能退化从剪报将重建被截去的样品根据其它样品在oversampled signals.In [ 44 ] oversampled 信号重建被使用补尝信号噪音比(SNR)degradation 由于截去为剪报门限的低值。在[ 45 种] 重申剪报噪声的估计和取消是proposed.This 技术盘剥事实截去的噪声由可能被再创造在接收器和随后被去除的一个已知的过程引起。