CF-Based Adaptive PAPR Reduction Method for Block Diagonalization-Based Multiuser MIMO-OFDM Signals

This paper investigates the application of a previously proposed adaptive peak-to-average power ratio (PAPR) reduction method based on clipping and filtering (CF) to block diagonalization-based multiuser multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) transmission. Assuming that the total number of receiver antennas is less than that for the transmitter antennas, we introduce virtual streams used only for PAPR reduction and the precoding matrix for these virtual streams, where the virtual streams do not impart interference to the actual data streams. Since the interference caused by the clipping operation is concentrated in the virtual streams and consequently restricts the interference to the actual data stream, the proposed method can significantly improve the sum capacity compared to the conventional CF method for a given PAPR. Simulation results show the capacity gain using the proposed method compared to the conventional method.