Method for Generating Peak Cancellation Signals in Complexity-Reduced PAPR Reduction Method Using Null Space in MIMO Channel for MIMO-OFDM Signals

In this paper, we investigate efficient methods for generating peak cancellation (PC) signals in a complexity-reduced algorithm for a peak-to-average power ration (PAPR) reduction method using the null space in a multiple-input multiple-output (MIMO) channel for MIMO-orthogonal frequency division multiplexing (OFDM) signals. The complexity-reduced algorithm performs vector-level signal processing in the PC signal in addition to the transmission signal at each transmitter antenna so that the PC signal is transmitted only to the null space in the MIMO channel. In this paper, we propose three methods to control the directional vector in the PC signal, which is a dominant factor in the achievable PAPR performance of the algorithm. Computer simulation results show that among the three methods, the method in which the ideal peak reduction vector is projected onto the null space in the MIMO channel to generate a directional vector in the PC signal achieves the best PAPR reduction performance for a given computational complexity.