Trellis Shaping Using Clipping-based Metric with Improved PAPR Reduction for OFDM Signals

Abstract

The well known drawback of orthogonal frequency-division multiplexing (OFDM) signals is its high peak-to-average power ratio (PAPR). Trellis shaping (TS) is known as one of the effective PAPR reduction techniques for OFDM without any distortion. TS controls transmit QAM symbols by selection of a suitable codeword that leads to reduction of PAPR of transmit OFDM signals, and the codeword is searched by Viterbi algorithm (VA). The major complexity of TS is its metric computation used by VA at the transmitter. Therefore, recently, a low-complexity metric calculation approach based on clipping has been proposed, but it becomes less effective as the constellation size of QAM increases. In this work, we propose a novel modification to the TS system with clipping-based metric that can preserve effective PAPR reduction performance even if the constellation size increases.