Energy Efficiency of Spectrum-Sharing Communication Systems

Energy efficiency is of paramount importance for studying spectrum-sharing green communications. We provide some understanding on the energy efficiency of spectrum-sharing systems which are subject to an average interference power constraint. The results present some interesting insight for designing spectrum-sharing systems. The secondary user transmission strategies are different from the well studied scenarios to maximize the ergodic capacity. The energy efficiency of the secondary user could be considered as a factor for control interference to the primary systems.