Wireless Downloading Delay under Proportional Fair Scheduling with Coupled Service and Requests: An Approximated Analysis

We propose a method for approximating the downloading delay for the downlink of a cellular system reminiscent of LTE (based on OFDMA), where users are randomly distributed in a cell, and the channel gain is formed by a distance dependent component (path loss), constant in time and frequency, and a time-frequency selective small-scale fading component, i.i.d. across the OFDMA resource allocation blocks. The proposed method yields an approximation of the user downloading delay cdf, through the solution of a system of fixed-point equations. It provides accurate results when the traffic demand is large.