Effect of non-uniform traffic distributions on performance of a cellular CDMA system

Abstract

This paper presents a study of the effect of nonuniform user traffic distributions on the performance of a CDMA cellular system. While, there have been many studies showing the capacity gains of CDMA over narrowband TDMA systems, most of these studies assume a uniform distribution of the user population across the coverage area. When compared to the more general case of non-uniform user distributions, the uniform user distribution leads to lower multi-user interference and consequently higher system capacity. Hence, use of these models can lead to overestimation of system capacity. In this paper, three non-uniform user density models are developed and used to analyze system performance in typical CDMA implementation scenarios. The results indicate that intra-cell multi-user interference dominates the total interference levels in most cases. As expected cell splitting is shown to improve the system performance. The most significant improvements in performance with cell-splitting are seen for a Gaussian user density model (when compared to linear or exponential user density models). The results in this paper provide additional insight into the performance of CDMA systems, and are useful for purposes of network planning and resource allocation.

Modeling Non-Uniform UE Distributions in Downlink Cellular Networks

“…Naturally, such flexibility is desirable, especially to study the current capacity-centric deployments where BSs are specifically deployed to be proximate to areas of high UE density. The most popular and perhaps the only available option to handle such scenarios is through detailed system level simulations, which are both time consuming and have to be focused on a limited range of system parameters [4], [5].…”

Closed-Form Path-Loss Predictor for Gaussianly Distributed Nodes

“…Sometimes, Probability Density Functions (PDFs) for users' position traffic are conjectured based on assumptions [6] [7]. Though, the most common hypothesis of nodes distribution used among researchers is founded on the uniform density [8]- [16].…”

“…Now, we substitute (10) into (9); then the result is used in the expression of (7). Further, to simplify the integrand, we .…”

Cellular-based Statistical Model for Mobile Dispersion

“…Further, in addition to looking at different cell contours, multiple researchers were also interested by the effect that clustering and user distributions may have on a network [4][5][6][7][8][9]. In short, they explored various nodes dropping near the BS, the edges and in an annulus within a cell.…”