Effects of imperfect power control and user mobility on a CDMA cellular network

Abstract

Code-division multiple-access (CDMA) is one of the major candidate access techniques for third generation systems, In recent years, a great deal of effort has been devoted to the study of the capacity it can support, This paper presents analytical derivations which allow the determination of the link availability in the presence of user mobility and power control imperfections in a CDMA network; moreover, it provides the guidelines which permit the implementation of a simple and flexible simulation tool which is independent of the specific CDMA implementations. As a matter of fact, the reported concepts can be applied to any asynchronous CDMA system, i.e., they hold both for the American Standard IS-95 and for the European Community Standard developed in the framework of the RACE CODIT Project

Call admission control in multiservice high altitude platform (HAP) W-CDMA cellular systems

“…Power control imperfections have been reckoned to be log-normally distributed [17], [18], [19], [29], [30], therefore, the power received by a base station can be expressed as P ci e αθ k , where P ci denotes the nominal received power for a class-i user with ideal power control, α is equal to ln(10)/10 and θ k is a zero-mean gaussian random variable with standard deviation σ p , which accounts for variations of the received power in dB owing to power control imperfections. Furthermore, R b is the information bitrate, W is the transmission bandwidth and is equal to 5 MHz in our study, I intra is the intracell interference, that is, the interfering power stemming from users located in the same cell, I inter is the intercell interference, namely the interfering power stemming from users located in neighboring cells, β denotes the efficiency of the base station Multiuser Detection (MUD) technique and n th is the thermal noise power.…”

Performance Analysis of an Integrated CS/PS Services CDMA System

“…is computed by (13) with a given intercell interference value, ρ represents the total intracell interference, and I intra is given by (3).…”

“…In [2], Jansen et al investigate the throughput of a packet CDMA cellular system, and further in [7], Manji et al study a multimedia indoor packet CDMA system. However, in both researches, the same method was applied that was used for circuit switch- ing (CS) systems in [1]- [3]. Because most packet services use the defer-first-transmission (DFT) transmission mode associated with auto-repeat-request (ARQ) schemes, in congestion control state, congestion control function usually delays the PS data service to guarantee CS service quality.…”

Adaptive S-ALOHA CDMA as an alternative way of integrating services in mobile environments

“…If comparisons try to include the physical layer as well as link layer elements, the model becomes easily untreatable and many mix-up and compensation effects may not allow reaching all conclusions in a very clear way. Therefore, many of the studies concerning the MAC layer simplify the physical layer model or even it is not included at all [8], [28], [29], while those research works covering, for example, power control, sectorization, voice activity monitoring, effects of shadowing and multipath propagation, etc., usually do not introduce any specific MAC protocol, traffic statistics, etc., [30], [31]. The reason is the untreatable models that could come up.…”