High energy efficient hybrid cooperative transmission strategy in heterogeneous networks

A hybrid cooperative strategy for Heterogeneous Network (HetNet) is proposed to improve its energy efficiency. By studying the two well-known cooperative strategies: Coordinated Multi-Point Joint Processing (CoMP-JP) and Coordinated Beamforming (CoMP-CB), it is found: CoMP-JP can reduce transmit power consumption with large array gain at the cost of high signal processing, backhauling and circuit power consumption; less signal processing and backhauling power is required under CoMP-CB, but with increased transmit power. Inspired by the observation, a hybrid cooperative strategy is presented to effectively reduce circuit power consumption, while fully exploiting advantages of CoMP-JP and CoMP-CB. Simulation results show that the precoder in the proposed strategy outperforms zero-forcing precoders in CoMP-JP and CoMP-CB in terms of energy efficiency. Further, higher spectrum efficiency can be realized with the proposed strategy.