Complete analytical framework for throughput calculation in WCDMA downlink TDD mode

Throughput and spectral efficiency are two important metrics that are used in performance evaluation of next generation cellular systems known as 3G. Wideband code division multiple access (WCDMA) has been adopted as an air interface technology for such systems. Tedious and time consuming Monte Carlo simulation schemes are usually needed to assess the performance of WCDMA in terms of throughput and spectral efficiency. In this paper, we present a simple analytical framework that can be used to evaluate the performance of downlink WCDMA operating in the time division duplex (TDD) mode without using computer simulations. An approximate closed form expression for the cumulative distribution function (CDF) of the user carrier-to-interference-plus-noise ratio (CINR) is first obtained, based on the 3GPP pathloss model, assuming lognormal shadowing and uniform cell loading. The throughput is then expressed in terms of this distribution and other system parameters. Numerical results are presented and show good agreement between both the proposed analytical framework and Monte Carlo simulations.