Spatial Modulation With Joint Permutation, Group and Antenna Indexes

Abstract

In this letter, a new schematic of spatial modulation with jointing permutation, group and antenna indexes (JPGA-ISM) is proposed to achieve more extra information bits by exploiting the permutation index (PI) domain. In the JPGA-ISM system, in order to increase the squared minimum Euclidean distance (MED) between the transmit vectors, two algorithm devices are designed. Based on the design of two algorithms, by exploiting the index domain, one PI matrix with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$D\times 2^{D}$ </tex-math></inline-formula> dimensions, in which each column of elements is treated as a spatial vector (SV), is developed to convey the PI bits. Then, each of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${D}$ </tex-math></inline-formula> elements of the specific SV with the PI bits is used to control two Switches, which feed the symbol index bits into the specific modulator and the corresponding element of the SV into the specific algorithm device, respectively. Furthermore, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${D}$ </tex-math></inline-formula> outputs from the specific algorithm devices are multiplied by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${D}$ </tex-math></inline-formula> components of the selected group index symbol and then modulated on <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${D}$ </tex-math></inline-formula> active transmit antennas to form a transmit vector, respectively. In addition, the modified pulse amplitude modulation (PAM) and secondary PAM constellations are designed. The spectral efficiency, the MED comparisons and the average bit error probability (BEP) are analyzed. Simulation results show that the JPGA-ISM outperforms other systems in terms of the BEP performance.