Energy Efficient Link Adaptation Approach for Mobile Users in TDD Multi-User MIMO Systems

In mobile communication, the battery technology is an important development. In order to improve the energy efficiency of mobile users in a multiuser multiple input multiple output systems (MU-MIMO), a new approach pilot and link adaptation algorithm can be developed Assuming reciprocity between uplink and downlink channels, the transmission of downlink is depends on estimation of uplink channel. Higher pilot power gives higher downlink rate can be achieved, it consumes higher energy consumption of mobile users. This paper explains the tradeoff between pilot power and channel estimation. The energy efficiency of different users can be dissociated because downlink average throughput of each user is independent of pilot powers of the users. and energy-efficient design can be done on a per user basis. Based on the analysis, we propose an uplink pilot and downlink link adaptation algorithm to improve the EE of mobile users. Simulation results are finally provided to demonstrate the significant gain in energy efficiency for mobile users.