Energy-efficient hybrid precoding for broadband millimeter wave communication systems

Due to the power consumption and hardware implementation cost limitation, hybrid analog and digital precoding is a promising candidate for millimeter wave (mmWave) large-scale multiple-input multiple-output (MIMO) systems. Most of the prior work on hybrid beamforming considers frequency-flat channels. However, in practice, thanks to the large amount of available spectral resource, mmWave communication systems are expected to be broadband with frequency selective channels. In this paper, we focus on the design of the energy efficient transmission for broadband mmWave MIMO orthogonal frequency division multiplexing (OFDM) communication systems. A low complexity optimization algorithm is proposed to calculate the hybrid radio frequency (analog) and baseband (digital) precoding matrices. Extensive numerical results are provided to evaluate the energy efficiency performance of the system and confirm the effectiveness of the proposed algorithm.