Low-complexity energy efficiency maximization protocol for MIMO-OFDM systems

We present a low-complexity link adaptation protocol for maximizing energy efficiency (EE) of MIMO-OFDM systems. We prove that the energy efficiency is a single-peaked quasiconcave function of transmit power and develop an iterative algorithm to find near-optimal transmit power. We further prune the search space by analyzing the singular values of the channel. The resulting link adaptation protocol achieves orders of magnitude reduction in complexity compared to the brute force search method without noticeably sacrificing the performance.