Analytical Model of Proportional Fair Scheduling in Interference-limited OFDMA/LTE Networks

TL;DR

An analytical model for the SINR distribution of the scheduled subcarriers of an OFDMA system with proportional fair scheduling is presented and it is shown that the models are approximate estimators for the performance of rate-based proportionalFair scheduling, while they outperform some simpler prediction models from related work significantly.

Abstract

Various system tasks like interference coordination, handover decisions, admission control etc. in upcoming cellular networks require precise mid-term (spanning over a few seconds) performance models. Due to channel-dependent scheduling at the base station, these performance models are not simple to obtain. Furthermore, upcoming cellular systems will be interference-limited, hence, the way interference is modeled is crucial for the accuracy. In this paper we present an analytical model for the SINR distribution of the \textit{scheduled} subcarriers of an OFDMA system with proportional fair scheduling. The model takes the precise SINR distribution into account. We furthermore refine our model with respect to uniform modulation and coding, as applied in LTE networks. The derived models are validated by means of simulations. In additon, we show that our models are approximate estimators for the performance of rate-based proportional fair scheduling, while they outperform some simpler prediction models from related work significantly.

Figures (6)

• Figure 1: MS location for model validation
• Figure 2: Comparison of the estimated SINR PDF model vs. simulations
• Figure 3: Comparison of the estimated rates vs obtained rates from simulations
• Figure 4: Rate estimation comparison (model) for independent vs uniform MCS (model) vs obtained rates from simulations
• Figure 5: Rate estimation comparison (models) for independent vs uniform MCS vs rate scheduler