With the growth of wireless networks, the challenges of sustaining higher data rates and coverage, coupled with the requirement for high quality of services, need to be addressed. The use of spatial diversity proves to be an attractive option due to its ability to significantly enhance network performance without additional bandwidth or transmission power.
The talk will focus on the mathematical optimization techniques for relay networks. Relay transmission is an important technique for increasing the capacity of the network and reducing the required transmit power. The design of relays for multi-user wireless network is an important research topic. The wireless relay network, however, has a problem i.e. multiple access interference occurs since there are multiple transmission links in a network. With that motivation, a strategy should be applied that minimizes interference and at the same time improves the power efficiency of the relay system. An iterative beamforming technique is proposed that aims to maximize the minimum received signal-to-interference and noise ratio over all receivers in a relay network, under a total power constraint in order to ensure user fairness. It is demonstrated that by applying an iterative algorithm together with convex optimization techniques, we are able to provide a balanced SINR over all transceivers by controlling the power of each user. The performance of this SINR balancing technique has been verified using MATLAB simulation results.
Talk slides in pdf [~1,2MB]http://www.iit.demokritos.gr/docs/seminars/bournaka-slides.pdf