A Pilot Symbol Pattern Enabling Data Recovery Without Side Information in PTS-Based OFDM Systems

Partial transmit sequence (PTS) scheme is one of the most popular peak-to-average power ratio (PAPR) reduction schemes for orthogonal frequency division multiplexing (OFDM) systems. In the PTS scheme, one OFDM symbol is partitioned into disjointed sub-blocks, and each sub-block is multiplied by a phase factor to generate signals with low PAPR. For data recovery, receivers must have side information (SI), e.g., phase factors, from transmitters. In this letter, a novel data recovery scheme in PTS-based OFDM systems without SI is proposed. In the proposed scheme, an additional pilot symbol is intentionally inserted at the end of each sub-block, so that efficient data decoding based on channel estimation can be executed with known pilot symbols. Simulation results show that the BER performance of the proposed scheme without SI is approximately the same as those of the PTS scheme with perfect SI and a maximum likelihood decoding scheme. Considering the cost for SI encoding and decoding, the proposed scheme is practically more advantageous over the PTS scheme.

I. Introduction

Orthogonal frequency division multiplexing (OFDM) has been widely adopted in various application systems such as digital audio/video broadcasting systems, wireless LANs, and other emerging wireless broadband systems. However, OFDM systems suffer several drawbacks such as sensitivity of carrier frequency offset and high peak-to-average power ratio (PAPR). Of these drawbacks, high PAPR causes nonlinear distortion at high power amplifier and reduces its power efficiency. Therefore, many PAPR reduction schemes have been reported in the literature [1].