Spectral efficiency of cooperative relaying with imperfect channel estimation

It is well known that cooperative relaying has the potential to improve the performance of end-to-end wireless communications. However, compared to point-to-point communications, implementing cooperative relaying requires much more overhead. For example, more complicated coordination and transmission schemes are required. In this paper, the spectral efficiency of cooperative relaying is investigated, taking into account the overhead to acquire essential channel state information, as well as that required to select the relay(s). A comparison of three cooperative relaying schemes (Timer-based Best-Select relaying, Dis-STBC All-Select relaying, and M-group All-Select relaying) is presented. Numerical results are further provided to illustrate the impact of the overhead on the spectral efficiency.