Subcarrier Interleaved Index Modulation Assisted OFDM Backscatter Communication

In this letter, we propose a subcarrier interleaved index modulation assisted orthogonal frequency division multiplexing (SIIM-OFDM) scheme for backscatter system. Specifically, the tag data vector, modulated with subcarrier index modulation (IM), is reconstructed leveraging the combined permutation and Hadamard matrix to mitigate the sensitivity of the inter-carrier interference. Then we derive the average bit error probability (ABEP) for the SIIM-OFDM backscattered signal and analyze the asymptotic detection performance bound of the proposed system. Furthermore, a hardware verification prototype is built to validate the proposed scheme. Experimental results and simulations validate that the proposed SIIM-OFDM backscatter achieves significant performance gains compared to the existing schemes.