Comparative forward link traffic channel performance evaluation of HDR and 1XTREME systems

Abstract

This paper presents a comparison of the forward link performance of the HDR and 1XTREME systems. Both systems have been proposed as possible evolutionary paths for the 1.25 MHz cdma2000 system, and have been designed to enable high data rate packet transmission. Link-level performance is evaluated by chip-level time-domain simulation of the forward data traffic channel in the presence of additive white Gaussian noise, and is then used in a system-level simulator modeling a network of 19 three-sector cells. The system-level simulator accounts for slow and fast fading and two types of multipath channel profiles, as described by the pedestrian A and vehicular B ITU-R channel models. The packet scheduling is performed using a proportionally fair (PF) scheduler. The systems use bit rate adaptation and hybrid ARQ to achieve 1% packet error rate (PER). All users in the system are assumed to always have data packets available for transmission. System performance is evaluated for an embedded sector in terms of average sector throughput as a function of the number of users, distributions of data rates, and individual throughputs over a set of users. Results show the benefits of multiuser diversity exploited by the PF scheduler, and present throughput and fairness comparisons for the two systems.