Channel estimation for OFDM-IM systems

Abstract

Orthogonal frequency division multiplexing with index modulation (OFDM-IM) has been recently proposedto increase the spectral efficiency and improve the error performance of multicarrier communication systems. However,all the OFDM-IM systems assume that the perfect channel state information is available at the receiver. Nevertheless,channel estimation is a challenging problem in practical wireless communication systems for coherent detection at thereceiver. In this paper, a novel method based on the pilot symbol-aided channel estimation technique is proposed andevaluated for OFDM-IM systems. Pilot symbols, which are placed equidistantly, allow the regeneration of the response ofthe channel so that pilot symbol spacing can fulfill the sampling theorem criterion. Our results shows that the low-passinterpolation and SPLINE techniques perform the best among all the channel estimation algorithms in terms of bit errorrate and mean square error performance.