A New Analysis of the DS-CDMA Cellular Uplink Under Spatial Constraints

TL;DR

This paper introduces a detailed analysis of DS-CDMA cellular uplinks considering spatial constraints, providing closed-form expressions for outage probability and rate, and exploring network design implications under various power and rate control policies.

Contribution

It offers a more accurate analytical framework for DS-CDMA uplinks with spatial constraints, enabling improved network design and resource allocation strategies.

Findings

Closed-form expressions for outage probability and rate.

Impact of minimum base-station separation on network performance.

Variable-rate policies can enforce outage constraints on every uplink.

Abstract

A new analysis is presented for the direct-sequence code-division multiple access (DS-CDMA) cellular uplink. For a given network topology, closed-form expressions are found for the outage probability and rate of each uplink in the presence of path-dependent Nakagami fading and log-normal shadowing. The topology may be arbitrary or modeled by a random spatial distribution for a fixed number of base stations and mobiles placed over a finite area with the separations among them constrained to exceed a minimum distance. The analysis is more detailed and accurate than existing ones and facilitates the resolution of network design issues, including the influence of the minimum base-station separation, the role of the spreading factor, and the impact of various power-control and rate-control policies. It is shown that once power control is established, the rate can be allocated according to a fixed-rate or variable-rate policy with the objective of either meeting an outage constraint or maximizing throughput. An advantage of the variable-rate policy is that it allows an outage constraint to be enforced on every uplink, whereas the fixed-rate policy can only meet an average outage constraint.