Improvement of Security in Communication System Using Time Reversal Division Multiple Access

In broad-band communications, wide range of frequencies are available allowing more information to be transmitted in a given amount of time. The multi-path effect makes high speed broad-band communication a very challenging task due to the severe inter-symbol interference (ISI). To resolve this problem, multicarrier modulations are needed at the receiver to alleviate the ISI. A novel concept of time-reversal division multiple access (TRDMA) has been introduced as a wireless channel access method based on its high-resolution spatial focusing effect. Time reversal signal processing is a technique for focusing waves. This paper aims to develop a multi-user downlink system with both the single-input single-output (SISO) antenna scheme and its enhanced version with multiple-input single-output (MISO) antenna scheme and the system (MISO) performance are investigated in terms of its effective signal-to-interference-plus-noise ratio (SINR), the achievable sum rate and the achievable rates with outage.. In this work, simulation of TRDMA multiuser downlink system with both single and multiple transmit antennas (SISO and MISO case) were performed. The effective SINR (by varying number of multiple antennas), achievable sum rate and achievable rate with outage for MISO case were also simulated. The simulation results confirmed that satisfying performances are achieved which makes TRDMA a promising candidate for future low complexity broad band wireless communications.