Precoding and Transmit Antenna Subarray Selection for Secure Hybrid Spatial Modulation

Spatial modulation (SM) is a particularly important form of multiple-input multiple-output (MIMO), which uses both symbols and antenna indices to carry information. In this paper, avoid the high cost circuit complexity SM, we consider hybrid SM system with precoding transmitter architecture, combining digital precoder an analog precoder. such system, carried out secure transmit subarray selection (TASS) methods. Two methods, called maximizing approximate secrecy rate (SR) via gradient ascent (Max-ASR-GA) SR alternating direction method multipliers (Max-ASR-ADMM), are proposed improve performance. As for TASS, high-performance (Max-ASR) first presented. To reduce its complexity, two low-complexity TASS namely eigenvalue (Max-EV) product signal-to-interference-plus-noise ratio artificial noise-to-signal-plus-noise (Max-P-SINR-ANSNR), proposed. Simulation results demonstrate that Max-ASR-GA Max-ASR-ADMM precoders harvest substantial performance gains over existing method. For three methods Max-ASR, Max-EV, Max-P-SINR-ANSNR perform better than leakage Particularly, Max-EV at expense little loss compared Max-ASR.