  Coordinated multipoint (CoMP) joint transmission (JT) can save a great deal
of energy especially for cell-edge users due to strengthened received signal,
but at the cost of deploying and coordinating cooperative nodes, which degrades
energy efficiency (EE), particularly when considerable amount of energy is
consumed by nonideal hardware circuit. In this paper, we study energyefficient
cooperation establishment, including cooperative nodes selection (CNS) and
power allocation, to satisfy a required data rate in coherent JT-CoMP networks
with non-ideal power amplifiers (PAs) and circuit power. The selection priority
lemma is proved first, and then the formulated discrete combinatorial EE
optimization is resolved by proposing node selection criterion and deriving
closedform expressions of optimal transmission power. Therefore, an efficient
algorithm is provided and its superiority is validated by Monte Carlo
simulations, which also show the effects of non-ideal PA and the data rate
demand on EE and optimal number of active nodes.
