Investigation of RLS beamforming algorithm interms of energy efficiency

Abstract

This work investigates the energy efficiency of Recursive Least Square (RLS) beamforming algorithm by developing a new energy model, which is a function of beam width, range, instantaneous signal to noise plus interference ratio (SNIR) and inter element spacing. It analyzes the effect of varying inter element spacing on linear array geometry for energy efficient beam formation. We evaluated the amount of energy saved and showed the advantage of selecting a better inter-element spacing for smart antenna installation. We also showed the advantage of checking the SNIR status of the user signal before releasing the beam energy from the base station antenna system. The result show that, installing antenna elements with 0.5λ separation has better energy efficiency than smaller separation distance (0.1λ) or wider separation distance (1λ). Furthermore, it indicates that knowledge of the status of the user signal SNIR, facilitates for the base station to adaptively control the release of energy and to reduce the linear increment of energy per range.