Alternate Transmission Relaying Schemes for MIMO Wireless Networks

Enormous gains of using multiple antennas at both the transmitter and the receiver known as multiple-input multiple-output (MIMO) in wireless communication system have been predicted. Especially, significant improvements in spectral efficiency are given through spatial multiplexing which transmits independent data streams over multiple transmit antennas simultaneously. Recently, many researches demonstrate that similar performance gains are obtained in wireless relay networks with multiple antennas at each terminal. In this paper, we propose a relaying protocol named as alternate transmission relaying protocol which enhances the capacity of the given environment and describe the capacity of MIMO wireless relay networks for the proposed relaying protocol. We consider a system model which has K relay terminals between a designated source terminal and a designated destination terminal. The proposed protocol assumes that no interference exists among the relay terminals. The K relay terminals receive or transmit a signal alternately without an interference. Several singular value decomposition (SVD) based relaying schemes are proposed for the proposed relaying protocol to perform a coherent combining at the destination terminal. In addition, a weight matrix for each relay terminal is designed to increase the capacity of the relaying schemes. We show the theoretical derivations and the simulation results of the proposed schemes in the following sections. Those demonstrate an effectiveness of the proposed schemes.