Successive PAR Reduction in (MIMO) OFDM

A successive scheme for PAR reduction in (MIMO/ SISO) OFDM is presented, where K (parallel/consecutive) OFDM frames are treated jointly. Employing Reed-Solomon codes further candidate OFDM frames are generated and assessed successively; the currently best K are selected for possible transmission. The procedure stops if (i) all K best frames stay below a given tolerable PAR limit, or (ii) the maximally allowed number of candidates is exhausted. Thereby complexity compared to other PAR reduction schemes can be reduced significantly. Analytical derivations show that for PAR limits in the region of the "critical PAR" value xicrit = log(D), with D being the number of carriers, the average number candidates is close to Euler\´s number e = 2.71828..., which is particularly low.