Energy-efficiency spectral-efficiency trade-off in interference limited wireless networks.

Presenter: Ahmad Mahbubul Alam

Abstract: Characterizing the energy efficiency-spectral efficiency (EE-SE) region considering the static circuit power consumption is becoming increasingly important. One of the used strategies to increase the SE of cellular network is to reuse the frequency bandwidth over relatively small areas. The major issue in this case is higher interference caused by the transmission on the same frequencies. We obtain a parametric expression of the interference to signal ratio with a curve fitting approach to study the EE-SE tradeoff when several frequency reuse factors are considered, and propose a new characterization, called the epsilon-EE-SE tradeoff, when shadowing is considered.

On the other hand, densification of the networks (e.g. small cells or multi-user multiple input single output, MU-MISO) potentially increases the area spectral efficiency (ASE). The total energy consumption of the wireless networks increases due to the large amount of circuit power consumed by the dense network structures, leading to the decrease of EE. In downlink, precoders are used in space division multiple access (SDMA) MU-MISO cellular networks to improve the SINR. We derive a closed-form expression for ASE and EE with SLNR precoder in the asymptotic regime, i.e. when the number of antennas and users grows to infinity, using stochastic geometry. Unlike conventional SLNR precoders, the average signal-to-interference-plus-noise ratio and the leakage to other cells are considered in a geometry dependent network.