Study of PAPR reduction using coded PTS in 8×8 MIMO-OFDM systems

This paper presents a study of peak-to-average power ratio (PAPR) reduction using coded partial transmit sequence (PTS) in 8×8 multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems. MIMO-OFDM achieves large-capacity wireless communication, and has been adopted in such as IEEE802.11n/ac standard wireless LAN systems. PAPR indicates the ratio of peak power to average power. High PAPR causes waveform distortion due to nonlinear amplifier characteristics. PTS is one of PAPR reduction methods to prevent communication quality degradation. PTS performs phase rotation to OFDM modulated signals to reduce the peak power. We have to increase the number of possible phase patterns in order to obtain enough PAPR reduction. Coded PTS is used to reduce computational cost of PTS by using codebook. In the case of MIMO-OFDM systems, we have to use the same phase pattern of PTS for each stream due to difficulty of detection. In this paper, we have evaluated PAPR reduction by the proposed coded PTS in 8×8 MIMO-OFDM systems. The evaluation result shows that low error transmission can be achieved by using coded PTS and RS code, and PAPR reduction is about 1.7 dB. In comparison with PTS, coded PTS can achieve 94% computational cost reduction.