Optimal Clipping Value for PAR Reduction of OFDM

Clipping and filtering (CF) is a simple but effective technique for peak-to-average ratio (PAR) reduction of orthogonal frequency division multiplexing (OFDM) signals. This paper determines the optimal clipping value for the CF method in order to maximize the power efficiency of the high power amplifier (HPA). A transmission spectral mask is placed on the output of the HPA as a design constraint in determining the optimal clipping value. The optimal clipping value is obtained for each specified bit error rate (BER) level. Results show that the optimal clipping value maximizes the efficiency of the HPA modelled as a travelling wave tube amplifier (TWTA), without causing a deterioration in BER performance.