# A Low Complexity Subcarrier Activation Scheme for OFDM with Index Modulation

## DOI:

https://doi.org/10.3103/S0735272724020018## Keywords:

Orthogonal frequency division multiplexing, subcarrier index modulation, subcarrier activation pattern, direct subcarrier activation## Abstract

In orthogonal frequency division multiplexing with index modulation (OFDM-IM) data is mapped to subcarrier activation

patterns (SAPs) by using look-up tables or combinatorial schemes. The complexity of these mapping schemes increases

with the number of subcarriers. Therefore, they are applied to subgroups of subcarriers, but unfortunately at the expense of

a reduction in the amount of data loaded to an OFDM block. In this paper, a low-complexity direct data to SAP mapping is

proposed, the necessary analysis to determine the analytical bit error rate (BER) is presented, then computer simulations are

performed to find and compare theoretical and simulated BER results under frequency selective Rayleigh fading channel. The

proposed scheme can load more data bits to an OFDM block, as compared with conventional schemes. The results from Computer

simulations demonstrate the superiority of OFDM-IM system using the proposed scheme over conventional OFDM-IM in terms

of BER performance.

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