A Novel Concurrent Papr Reduction Algorithm for Stbc Mimo-ofdm Systems

Multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) is a promising candidate for 4G broadband wireless communications. However, one main disadvantage of MIMO-OFDM is that the signals transmitted on different antennas might have large peak-to-average power ratio (PAPR). A new concurrent PAPR reduction algorithm based on the property of orthogonal space-time block coded (STBC) is proposed in this paper. We proved that the conjugate symbols transmitted on two antennas have same PAPR property, with which, the computational complexity cost of the proposed algorithm can be reduced significantly compared with the conventional concurrent PAPR reduction algorithms, such as concurrent partial transmit sequences (PTS) and concurrent selective mapping (SLM). Furthermore, a criterion of minimum maximum (minmax) is proposed, which shows better PAPR performance than the criterion of minimum average (minaverage) in conventional concurrent algorithms. Simulation results demonstrate that the performance of the proposed algorithm outperforms the conventional concurrent algorithms. Key Words, MIMO, OFDM, STBC, PAPR, SLM, PTS.