Performance of a fixed‐beam system in the is‐95 CDMA forward link

Abstract

Abstract. We study the performance of a fixed-beam system in the forward link of IS-95 CDMA systems by means of Monte Carlo simulations. The simulations are performed using a comprehensive model of the forward link which includes correlated shadowing, soft and softer handoff. and transmit power allocation. The effects of user distribution, softlsofter handoff threshold, and multipath diversity are examined. We find that the availability of signal diversity plays an important role in the system performance. When the soft handoff threshold is decreased from -12 dB to -18 dB. capacity increases by 15%. but handoff overhead more than doubles. When fifty percent of users have 2-ray multipath. capacity increases by 18%. Thus, the availability of multipath in the system has a dramatic influence on forward link capacity. A non-uniform distribution using a "highways" model reduces capacity by more than a half. This shows that for successful implementation of a fixed-beam system, it is important to plan cell sites in a way that keeps loading uniformly distributed in azimuth.

Effects of user distribution on the delay performance of downlink packet access in 3GPP WCDMA networks

“…The network system model used in this paper is similar to that in [7,8], which consists of 12 hexagonal cells each with a base station at its center as shown in Figure 1. We assume 120…”

“…In order to model correlated shadowing, we create jointly Gaussian random variables for two different base stations from a mobile user with the appropriate crosscorrelations. Following [7,8], we assume the shadowing correlation coefficient to be 0.74 for the following pairs of base stations.…”

On the Analysis of Switched-Beam Antennas for the W-CDMA Downlink

“…Mootri, Stützle, and Paulraj reported a capacity gain of four to five times that of a standard sectorized IS-95 forward link in [24] when a 12-beam system is employed. The field trials reported in [19] showed a 3-dB improvement in the downlink carrier-to-interference ratio for a similar system.…”