Practical Hardware Considerations for the Design of Hybrid Precoding Systems

In this paper we describe practical implications of employing communication schemes with analog beamforming networks (ABFN). Specifically, we formulate realistic constraints for standard ABFN based on the S-parameters of the hardware components involved in their implementation. We concentrate on flexible fully-connected ABFN and Butler networks for im- plementing the discrete Fourier transform (DFT) in the analog domain. The results presented in this paper show that both the performance and the energy efficiency (EE) of conventional hy- brid precoding designs are severely affected when the additional power losses introduced by practical ABFN are accounted for.