Improved phase factor computation for the PAR reduction of an OFDM signal using PTS

The peak-to-average power ratio (PAR) of an orthogonal frequency-division multiplexing (OFDM) signal can be substantially larger than that of a single carrier system. Partial transmit sequence (PTS) combining can improve the PAR statistics of an OFDM signal. As PTS requires an exhaustive search over all combinations of allowed phase factors, the search complexity increases exponentially with the number of subblocks. In this letter, we present a new algorithm for computing the phase factors that achieves better performance than the exhaustive search approach.