Error Probability Analysis for Rectangular Differential OFDM With Index Modulation Over Dispersive Channels

Abstract

In this letter, a novel forgetting factor aided rectangular differential (RD) orthogonal frequency division multiplexing (OFDM) with index modulation (IM) is proposed for dispersive channels, which amalgamates the concept of RD coding for exploiting the benefits of OFDM-IM with the absence of channel state information (CSI). To be more specific, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${N}$ </tex-math></inline-formula> subcarriers are partitioned into <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${G}$ </tex-math></inline-formula> subblocks for IM mapping. By employing RD coding during two adjacent subblocks, non-coherent detection without CSI can be carried out at the receiver. To further improve the performance, a novel forgetting factor is exploited at the receiver, which can be optimized via a closed form without extra complexity. Based on the derived forgetting factor, the upper bound of the average bit error probability (ABEP) of the proposed RD-OFDM-IM scheme is derived and is validated by the simulation results. Both the theoretical and simulation results indicate that the proposed RD-OFDM-IM scheme is capable of providing a considerable performance gain over its conventional differential OFDM (D-OFDM) counterpart.