DIRECTION MODULATION AT THE MODULATOR FOR PHYSICAL LAYER SECURITY

Abstract

Beam forming and directional modulation (DM) are known technologies at the antenna level. DM currently requires radio frequency (RF) phase shifting, etc., at the antenna with either multiple antennas or a phased array. We consider accomplishing DM in the modulator vice the antenna. The goal of DM is to transmit a signal in such a way as to have the signal be received undistorted at the intended receiver and hopelessly distorted at nearly any other location, thereby providing some physical layer security. In this thesis, we explore the notion of accomplishing this at baseband in the modulator instead of in the RF section, thereby achieving a simpler radio design. Currently, the complexity of directional modulation at the RF section brings a cost in either manufacturing or time. Herein, we discuss the theory and implementation of directional modulation and simulate its performance for noisy channels, both line-of-sight and non-line-of-sight.