An efficient sphere decoding approach for PTS assisted PAPR reduction of OFDM signals

It is well known that one of the main drawbacks of orthogonal frequency division multiplexing (OFDM) is the potentially high peak-to-average power ratio (PAPR) of the (OFDM) signal. Partial transmit sequence (PTS) is a widely accepted method in reducing PAPR of OFDM signal. As traditional optimal PTS (OPTS) technique requires an exhaustive search over all the combinations of the allowed phase factors the search complexity increases exponentially with the number of sub-blocks. In this paper, a new precalculated radius sphere decoding (PRSD) is presented. It can achieve the same PAPR performance but at lower computational complexity compared with OPTS and existing sphere decoding (SD) approach at zero decoding failure rate.