Reducing the Clipping Noise in OFDM Systems by Using Oversampling Scheme

Linjun WU  Shihua ZHU  

IEICE TRANSACTIONS on Communications   Vol.E88-B   No.7   pp.3082-3086
Publication Date: 2005/07/01
Online ISSN: 
DOI: 10.1093/ietcom/e88-b.7.3082
Print ISSN: 0916-8516
Type of Manuscript: LETTER
Category: Wireless Communication Technologies
orthogonal frequency division multiplexing (OFDM),  peak-to-average power ratio (PAR),  oversampling,  

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In an Orthogonal Frequency Division Multiplexing (OFDM) systems, the Peak to Average power Ratio (PAR) is high. The clipping signal scheme is a useful and simple method to reduce the PAR. However, it introduces additional noise that degrades the systems performance. We propose an oversampling scheme to deal with the received signal in order to reduce the clipping noise by using finite impulse response (FIR) filter. Coefficients of the filter are obtained by correlation function of the received signal and the oversampling information at receiver. The performance of the proposed technique is evaluated for frequency selective channel. Results show that the proposed scheme can mitigate the clipping noise significantly for OFDM systems and in order to maintain the system's capacity, the clipping ratio should be larger than 2.5.