Adaptive Clipping Level Control for OFDM Peak Power Reduction Using Clipping and Filtering

Takeo FUJII  Masao NAKAGAWA  

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E85-A   No.7   pp.1647-1655
Publication Date: 2002/07/01
Online ISSN: 
DOI: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Multi-dimensional Mobile Information Networks)
Category: 
Keyword: 
OFDM,  peak power problem,  clipping and filtering,  adaptive clipping level control,  

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Summary: 
In this paper, we focus on an OFDM peak power reduction method that uses clipping and filtering. This method can reduce the peak power of OFDM via clipping, and can also reduce the out-band emission via filtering, even if a nonlinear amplifier is used. However, the filtering causes peak power regeneration. For purposes of reducing the effect of peak power regeneration, we propose an adaptive clipping level control method for OFDM peak power reduction, as part of a technique using clipping and filtering. In this method, the clipping level is optimized by checking the peak power regrowth which is caused by inserting a filter, by using a multi-stage filtering simulator. Thus the peak power is adjusted to the target PAPR. If the target PAPR is decided to be the saturation power of an amplifier, the bit error rate performance is improved without increasing the out-band emission. In order to confirm the effectiveness of the proposed system, we evaluate its performance by using computer simulation.