Decoding Schemes for Amplify-and-Forward Cooperative OFDM-Based Wireless LAN Systems

Cooperative communication can be regarded as virtual multiple-input multiple-output (MIMO) systems where distributed multiple terminals behave as a virtual antenna array. This paper presents two space-time coding (STC) methods, i.e., the Golden code and Alamouti code, for cooperative orthogonal frequency division multiplexing (OFDM)-based wireless local area network (LAN) systems. We propose a decoding scheme for both STC methods. The proposed decoding scheme for the Golden code has approximate maximum likelihood (ML) property, and the one for the Alamouti code has exact ML property. we show the performances of the two proposed schemes for various typical relay locations through simulations. Simulation results reveal that energy gain greater than 2.1 dB can be obtained with the proposed schemes over non-cooperative (direct) communication in each relay location at a packet error rate of 0.1.