PAPR reduction techniques in wireless LAN transceivers.

摘要

Orthogonal frequency division multiplexing (OFDM) overcomes the problem of multi-path fading in wireless communications. However, the potentially high peak-to-average-power ratio (PAPR) of OFDM is a drawback of this modulation. The use of Golay sequences can limit the PAPR in OFDM signals. In the first part of the thesis, we consider efficient maximum-likelihood decoding (MLD) of the Golay sequences by using the principle of sphere decoding. Our algorithms result in maximum likelihood BER performance and require substantially fewer computational operations than other known MLD algorithms. We also study the design of an efficient optimizer for the partial-transmit-sequence and we introduce a low-complexity optimization algorithm that offers optimum PAPR reduction performance. Lastly, we investigate the effect of channel coding on a class of transceivers which employ standard array of linear block codes (STA), to reduce the sensitivity of the transceivers to channel distortion.