Uplink Performance Analysis for a Relay Based Cellular System

Abstract

Mobile cellular communication systems beyond third generation (3G) are expected to allow subscribers to access an unlimited amount of multimedia and/or voice data with a guaranteed quality of service (QoS) irrespective of their locations. There is therefore a general and continuing requirement to seek improvements to present cellular communication systems for the provisioning of greater throughput per subscriber. In this scope, a further portfolio of standards coined as fourth generation (4G) is currently under study which is intended to extend the capacity of 3G by at least one order of magnitude and offer an entirely packet switched network with data rates expected to range from 100 Mbps for vehicular mobility to lGbps for nomadic access. In order to meet the target of 4G systems, it is clear that the current 3G architecture which is based on a hierarchical cellular structure has to be upgraded. In [1], we introduced a novel relay based architecture termed as Basestation Relay Integration Deployment for "Gth" Enhancement (BRIDGE) as a promising candidate to improve coverage and enhance the capacity of 3G networks at the cell edge. This paper provides an overview of the mathematical analysis of the uplink performance for the integration of this relay based system in the conventional mobile cellular architecture. A comparative study of BRIDGE against the conventional sectorised cell structure for a single cell scenario is provided for performance analysis with respect to coverage, user capacity and transmits power for DS-CDMA system.

On the uplink performance and optimization of a relay-assisted cellular network

“…For direct path, by substituting P M into (5), the throughput can be obtained by (8). For a 2-hop path, again, t M →Rj ( m) = t R j →B ( m) gives the highest spectral efficiency.…”

“…There have been few studies on the uplink performance of the relay-assisted cellular systems [8]- [10]. In [8], the issues of capacity, cell coverage, and MS transmit power were considered in a relay-assisted CDMA network with six RSs under different frequency allocation methods.…”

“…In [8], the issues of capacity, cell coverage, and MS transmit power were considered in a relay-assisted CDMA network with six RSs under different frequency allocation methods. In [9], the uplink capacity of an 802.16j system was discussed, where a simplified one-dimensional model is analyzed for the maximal capacity gains, and fixed number of RSs with uniform placement is also simulated.…”

Area spectral efficiency of infrastructure-relay enhanced single-cell wireless systems

“…Both steps will require appropriate time/spectral resource allocation, which leads to a certain penalty to the overall link spectral efficiency. Previous works have shown that relay transmission can achieve higher spectral efficiency than direct transmission only if the direct source to destination link experiences much poorer fading condition than the relay links [6]. These results have, as such, generated considerable interest in opportunistic relaying systems [7].…”

“…We assume the mode selection is based on user location. Specifically, the service area is divided into two different coverage zones: the inner zone and the outer zone [6]. The inner zone is approximated by a circle with radius R bs while the outer zone by a ring with radius D − R bs , where D is the radius of the relay-enhanced cell.…”