On the diversity order of non-orthogonal amplify-and-forward over block-fading channels
Co-operative communication with relay assistance helps in enhancing the capacity of point to point links. Next-generation wireless communication systems require higher spectral efficiency and macroscopic coverage to support the quality of service needed for a wide variety of multimedia applications. Much research has been devoted to enhancing the spectral efficiency of wireless communication systems. Among these, relay based communication systems have attracted a great deal of attention thanks to their potential to deliver extended cell coverage and reduced power consumption. We discuss resource efficiency in relay systems, particularly in two-way and full-duplex relay systems that utilize multiple antennas and improved duplexing to enhance system efficiency. Besides, a theoretically optimal hybrid relaying, which allows a dynamic selection between AF relaying and DF relaying protocols with fullduplex relays or half-duplex relays, is also considered in the problem formulation and serves as a performance benchmark. . Simulation results demonstrate that the proposed source and relay design algorithms perform much better than the existing techniques in terms of probability of error Vs transmit power.