Joint switch controlling and subvectors permutation for quadrature index modulation with hybrid constellations

Abstract

AbstractIn this paper, the switch and permutation index domains are developed for improving the spectral efficiency (SE) and the reliability of wireless communication. Firstly, a new schematic of quadrature index modulation with hybrid constellation (QIM‐HC) is proposed to exploit the switch index domain. In the QIM‐HC system, all transmit antennas (TAs) are divided into multiple groups. In each group, with the control of one Switch, the symbol index bits are fed into the specific modulator and mapped into a data symbol. Then, the real and imaginary parts of the data symbol are respectively modulated by two selected antenna index (AI) vectors with two blocks of AI bits, resulting in the transmit vector. Furthermore, another new design, jointing permutation index and hybrid constellation for the QIM system (JPQIM‐HC), whose each group transmits different number of data symbols with the control of different number of switches, is proposed to develop the permutation index domain for further improving the SE. Finally, the analysis of the SE and the bit error probability are analyzed. Simulation results show a close match with theoretical results at the high signal noise ratio (SNR) region, and show the improvement of the bit error rate (BER) performance for the the proposed systems as compared with the other schemes such as signed quadrature spatial modulation.