Hybrid beamforming architectures provide promising solutions to harness the benefits of massive multi-input multi-output (MIMO) systems by incorporating phase shifters, switches or their combinations. This letter addresses the design of such architectures from an energy efficiency (EE) perspective. We provide closed-form expressions to compare several promising hybrid beamforming architectures, and also derive optimal numbers of antennas required for maximizing the EE. Our results indicate that the asymptotic closed-forms provide a good approximation even for relatively small number of antennas. Moreover, the combination of phase shifters and switches offers significantly higher EE against conventional PS-only architectures, while nearly preserving spectral efficiency.
|Journal||IEEE Wireless Communications Letters|
|Early online date||12 Jun 2018|
|Publication status||E-pub ahead of print - 12 Jun 2018|
- Array signal processing
- Fading channels
- hybrid beamforming
- Massive MIMO
- MIMO communication
- phase shifter selection.
- Phase shifters
- Power demand
- Radio frequency
ASJC Scopus subject areas
- Control and Systems Engineering
- Electrical and Electronic Engineering