OFDM COMUNICATION SYSTEM FOR REDUCING PAPR AND METHOD THEROF

摘要

The present invention relates to an OFDM communications system for reducing the peak to average power ratio (PAPR) and a method thereof. The OFDM communications system given in the present invention performs inverse fast Fourier transform for data signals to be transmitted to a receiver device and performs clipping for the inverse-fast-Fourier-transformed signals with a set threshold amplitude value. Then, the sizes of two or more subcarriers are determined by using a value calculated by comparing the clipped signals and the signals before the clipping, and the data signals are transmitted to the receiver device by using the subcarriers of which the sizes are determined. According to the present invention described above, a threshold value corresponding to each subcarrier is calculated using clipping noise and the sizes of the subcarriers are limited based on the calculated threshold value. By doing so, the interference due to the clipping noise which used to affect a main user in existing clipping techniques can be minimized and the increase of PAPR can be effectively reduced.