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Erlang capacity analysis of hybrid FDMA/CDMA systems supporting multi‐class services according to channel assignment methods
Author(s) -
Koo Insoo,
Yang Jeongrok,
Ahmad Aftab,
Kim Kiseon
Publication year - 2002
Publication title -
international journal of communication systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.344
H-Index - 49
eISSN - 1099-1131
pISSN - 1074-5351
DOI - 10.1002/dac.569
Subject(s) - erlang (programming language) , computer science , code division multiple access , erlang distribution , channel (broadcasting) , channel capacity , channel allocation schemes , computer network , markov chain , telecommunications , wireless , mathematics , theoretical computer science , exponential distribution , statistics , functional programming , machine learning
In this paper, we focus on the evaluation of the Erlang capacity for hybrid FDMA/CDMA systems supporting multi‐class services with two channel allocation schemes: independent carrier channel assignment (ICCA) and combined carrier channel assignment (CCCA). For the performance analysis, a multi‐dimensional Markov chain model is developed. The effect of the number of carriers of hybrid FDMA/CDMA system on the Erlang capacity is observed, and the optimum values of the system parameters such as the number of channel elements (CEs) and the number of carriers are selected with respect to the Erlang capacity. As a numerical example, we consider an FDMA/CDMA system supporting voice/data services. We find out that, even though the benefit of CCCA scheme over ICCA scheme is negligible for small number of CEs, the scenario changes significantly when the number of CEs increases beyond a certain point. An improvement of as much as 74% can be achieved in the Erlang capacity when 5 carriers are employed. We also find the capacity knees for different number of carriers. The results of this paper could be helpful in the traffic engineering of FDMA/CDMA systems providing multi‐class services. Copyright © 2002 John Wiley & Sons, Ltd.