Abstract
In this paper, 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, N
subcarriers are partitioned into G subblocks for IM mapping.
By employing RD coding during two adjacent subblocks, noncoherent
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.