Abstrakt

Design a Transmission Policies for Decode and Forward Relaying in a OFDM System

R.Krishnamoorthy, N.S. Pradeep , D.Kalaiselvan

Orthogonal Frequency Division Multiplexing (OFDM) is a leading physical layer transmission technique for high spectral efficiency and date rate in broadband wireless communication systems. Combining relaying architecture with OFDM transmission is a powerful technique for broadband wireless communication, and thus adopted in many current and next generation standards. Design of new transmission policies to improve Quality of Service (QoS) of OFDM bidirectional Decode and forward relaying has been proposed in this work. Where a pair of user exchange the information via assistance of Decode and Forward(DF) relay. Each user can communicate with other via three transmission mode: Direct transmission, one way relaying and two way relaying. We jointly optimize the transmission policies, including power allocation, transmission mode selection and sub carrier allocation has been considered. This is formulated mixed integer problem. Solve the problem in an asymptotically optimal manner by using dual method. The simulation result show that the proposed scheme can substantially improve system performance.