Multiple-Mode Permutation Matrix Modulation

The high spectral efficiency of spatial modulation-based schemes is generally achieved at the expense of requiring a larger number of antennas. Additionally, existing permutation matrix modulation-based schemes transmit $M$-ary phase shift keying ($M$-PSK) symbols using the same modulation order, which limits their flexibility. To address these issues, a novel multiple-mode permutation matrix modulation (MM-PMM) scheme is proposed in this paper. In MM-PMM, the permutation index, along with multiple-mode constellation and its index, are utilized to transmit information bits, thereby enhancing spectral efficiency. Furthermore, joint maximum likelihood detection (J-MLD) and low-complexity detection (LCD) methods are proposed to recover the transmitted bits. The bit error probability of the proposed MM-PMM scheme is also derived. Finally, the bit error rate (BER) performance of the proposed MM-PMM scheme is compared to that of benchmark schemes, and comparison results demonstrate that the proposed MM-PMM scheme achieves at least a 2 dB gain in BER performance over benchmark schemes.