A QPSK modulation scheme based on four dimensional antenna arrays

Abstract

A novel direction-dependent QPSK modulation technique based on four dimensional (4D) antenna arrays is proposed in this paper. The basic principle is that the antenna elements of different positions are used to transmit the in-phase and quadrature baseband signals. In this way, the QPSK modulation is formed in space and dependent on directions. Simulated results show that this technique offers a much narrower BER beam width and is suitable for physical-layer secure wireless communication.