Amplitude Clipping and Iterative Reconstruction of STBC/SFBC-OFDM Signals

As with orthogonal frequency-division multiplexing (OFDM), one main disadvantage of multi-input multi-output (MIMO) OFDM is the prohibitively large peak-to-average power ratio (PAPR) of transmitted signals on different antennas, which can be reduced by a deliberate amplitude clipping. However, clipping causes distortion that degrades the system performance. In this letter, we propose clipping noise mitigation techniques for space-time and space-frequency block coded (STBC/SFBC)-OFDMs. A new SFBC transmitter for clipped OFDM is proposed, and the optimum equalizer is derived for reconstruction of the clipped signals. Simulation results show that the proposed receivers effectively recover contaminated STBC/SFBC-OFDM signals with a moderate computational complexity.