Analytical results for capacity improvements in CDMA

Abstract

Abstmct-In this paper, we examine the performance enhancements that can be achieved by employing spatial filtering in code division multiple access (CDMA) cellular radio systems. The goal is to estimate what improvements are possible using narrow-beam adaptive antenna techniques, assuming that adaptive algorithms and the associated hardware to implement these systems can be realized. Simulations and analytical results are presented which demonstrate that steerable directional antennas at the base station can dramatically improve the reverse channel performance of multicell mobile radio systems, and new analytical techniques for characterizing mobile radio systems which employ frequency reuse are described using the wedge-cell geometry of [l]. We also discuss the effects of using directional antennas at the portable unit. Throughout this paper we will use phased arrays and steerable, fixed pattern antennas to approximate the performance of adaptive antennas in multipath-free environments.

Wideband CDMA network sensitivity function

“…Reverse link Erlang capacity under nonuniform cell loading is reported in [28]. The effects of adaptive base station antenna arrays on CDMA capacity have been studied, e.g., in [24], [29], and [30]. The results show that significant capacity gains can be achieved with quite simple techniques.…”

Application of APES to Adaptive Arrays on the CDMA Reverse Channel

“…As noted previously (assuming ergodicity and using the temporal average equation) (23) It can be shown that [see (24) and (25) …”

Dynamic Space-Code Multiple Access (DSCMA) System: A Double Interference Cancellation Multiple Access Scheme in Wireless Communications System

“…The performance of this joint multiple access system is also vulnerable to the non-uniform traffic. Although the performance of this joint multiple access system has been previously studied in several papers (Liberti & Rappaport, 1994), (Naquib et al, 1994), (Buracchini et al, 1996) and (Ng & Sousa, 1998), none of them considers to evaluate the most realistic of system performance in this joint multiple access. In this chapter, a new approach called dynamic space-code multiple access (DSCMA) system arising from the combination of CDMA and SDMA systems is designed, and its system performances are then investigated.…”