Phase Allocation Aspects of Interleave-Division Multiplexing from PAPR Prospective

Interleave-division multiplexing (IDM) is both a multiplexing and a modulation technique. When seen as a modulation technique the constellation is determined by the number of superimposed layers together with the amplitude and phase coefficients assigned to each layer. The most natural and also predominant selection is equal power allocation and uniform phase distribution. A well known fact is that superposition techniques lead to a high peak-to-average power ratio (PAPR). To investigate the effect of phase allocation on the PAPR, particle swarm optimization (PSO) is used to find good setups. The results show that for equal power allocation uniform phase distribution is optimal, but if unequal power allocation is used, then the phase distribution should be modified to significantly reduce the PAPR and at the same time to increase the theoretical performance limit.