Permutation Channel Modulation: New Index Modulation Mechanism for MIMO

In this paper, we propose a novel index modulation mechanism called permutation channel modulation (PCM) by exploiting spatial resource of multiple input multiple output (MIMO). A set of permutation matrices is treated as indices to convey information bits by modulating a block of bits to a permutation matrix. Assuming that channel state information at transmitter (CSIT) is known, modulated permutation matrix is multiplied to the singular values of MIMO channel matrix obtained from decomposing the channel matrix using singular values decomposition (SVD). Besides to a permutation matrix, information bits are also modulated to constellation symbols. Therefore, the transmitted signals contain two sources of information: a permutation matrix and constellation symbols. At the receiver, transmitted symbols and a permutation matrix are detected using our proposed detection scheme. We derive the capacity expression and define the optimal capacity by finding the optimal power allocation at each transmission. As performance measure, capacity of PCM is compared with existing techniques. Using 4 × 4, we find that the capacity of PCM is doubled and remains superior with higher antenna settings. Our work creates a new paradigm of index modulation for multiple antenna transmissions by exploiting its spatial resource and significantly improves the capacity and outage probability performances.