Cross-Layer Admission Control Policy for CDMA Beamforming Systems

Wei Sheng,Steven D Blostein

doi:10.1155/2007/14562

Abstract

A novel admission control (AC) policy is proposed for the uplink of a cellular CDMA beamforming system. An approximated power control feasibility condition (PCFC), required by a cross-layer AC policy, is derived. This approximation, however, increases outage probability in the physical layer. A truncated automatic retransmission request (ARQ) scheme is then employed to mitigate the outage problem. In this paper, we investigate the joint design of an AC policy and an ARQ-based outage mitigation algorithm in a cross-layer context. This paper provides a framework for joint AC design among physical, data-link, and network layers. This enables multiple quality-of-service (QoS) requirements to be more flexibly used to optimize system performance. Numerical examples show that by appropriately choosing ARQ parameters, the proposed AC policy can achieve a significant performance gain in terms of reduced outage probability and increased system throughput, while simultaneously guaranteeing all the QoS requirements.

Highlights

In a code division multiple access (CDMA) system, qualityof-service (QoS) requirements rely on interference mitigation schemes and resource management, such as power control, multiuser detection, and admission control (AC) [1,2,3]
This paper provides a novel framework which exchanges information among physical, data-link, and network layers, and as a result provides a flexible way to handle the QoS requirements as well as the overall system throughput
We propose a cross-layer AC policy combined with an automatic retransmission request (ARQ)-based ROP algorithm for a CDMA beamforming system

Summary

Introduction

In a code division multiple access (CDMA) system, qualityof-service (QoS) requirements rely on interference mitigation schemes and resource management, such as power control, multiuser detection, and admission control (AC) [1,2,3]. [4,5,6] rely on an asymptotic signal-to-interference ratio (SIR) expression proposed in [18] which requires a large number of users and a large processing gain. This specific signal model limits the application of the proposed AC policies. Motivated by these facts, in this paper, we investigate cross-layer AC design for an arbitrary-size CDMA system with multiple antennas at the base station (BS)

Objectives

Results

Conclusion