Capacity optimization of multi-input/multi-output relay channel by SADDE algorithm

In this paper, we use self-adaptive dynamic differential evolution (SADDE) to search for multi-input/multi-output (MIMO) relay locations and transmitter locations to reduce the outage probability in the indoor ultra-wideband (UWB) environment. Amplify-and-forward (AF) MIMO relay is chosen to improve the performance of the environment. We use the shooting and bouncing ray/image (SBR/image) method to compute the frequency response, which is used to compute capacity. The channel capacities for the linear antenna with 1 × 1 antenna, 3  3 spaced linear antennas, and 3 × 3 tri-polarized antennas are compared. First, we deploy the relay and transmitter at the equipartition area. It is found that there are some outage receiving points. Thus, the SADDE is employed to optimize the position of the relay and transmitter in order to reduce the outage probability. Numerical results show that the outage probability for the relay and transmitter location is reduced by SADDE. Moreover, it is found that the channel capacity for the tri-polarized antennas has increased when comparing to 3 × 3 spaced linear antennas. For the zero outage probability requirement, the signal to noise for the tri-polarized antennas is lower 6 dB than that for 3 × 3 spaced linear antennas.