Vector OFDM With Index Modulation

Abstract

The concept of index modulation (IM) has gained increased attention in recent years. As a member of the IM family, orthogonal frequency division multiplexing with index modulation (OFDM-IM), which is able to convey additional information bits using the indices of the active subcarriers, has emerged as an attractive physical layer transmission technique. Vector OFDM (V-OFDM) has inherently good peak-to-average-power ratio (PAPR) feature and good bit error rate (BER) performance due to the nearly full diversity gains achieved by most of its sub-blocks. In this paper, in order to improve the BER performance of OFDM-IM and reduce the PAPR of the transmit signal, we propose an enhanced OFDM-IM scheme termed vector OFDM with index modulation (V-OFDM-IM). In addition to the structure of the transceiver, a complexity reduced maximum likelihood detector is presented. To further reduce the detection complexity, a near-optimal detector based on sequential Monte Carlo technique is introduced. The average bit error probability of the proposed scheme is derived in closed form over frequency-selective block Rayleigh-fading channel. Both the theoretical and the simulation-based results show that, under the same spectrum efficiency, V-OFDM-IM outperforms the conventional OFDM-IM and OFDM.