Directed selected mapping for peak-to-average power ratio reduction in MIMO OFDM

Peak-to-average power ratio (PAR) reduction in OFDM using antenna arrays (MIMO OFDM) is considered. In particular, a generalisation of selected mapping (SLM), called directed SLM (dSLM), is introduced. It is shown that, in contrast to schemes proposed in the literature, dSLM utilises the potential offered by MIMO transmission. As a result, the complementary distribution function of the PAR exhibits a steeper decay, increased by a factor equal to the number of transmit antennas. This effect is similar to the diversity gain in error performance when using MIMO transmission