Delay-coded Communication for PHY Layer Security

The paper presents a novel technique based on timed-array for achieving a secure line-of-sight (LOS) wireless communication link. The timed-array spreads spatially the transmitted signal everywhere, undistorted in a specific region and distorted elsewhere. To achieve such an objective, optimal time-delays are computed by means of a Particle Swarm Optimizer. At the receiver side, the information can be decoded only using a rake receiver that knows the time-delay sequence used for transmitting the signal and it is in the proper location. Selected results illustrate the capability of the proposed approach in creating a secure wireless connection.