Title :
Trunk-resource-efficiency-controlling soft handoff based on fuzzy logic and gradient descent method
Author :
Homnan, Bongkarn ; Benjapolakul, Watit
Author_Institution :
Dept. of Electr. Eng., Chulalongkorn Univ., Bangkok, Thailand
Abstract :
This paper proposes a strategy for controlling trunking resource efficiency (TRE) in a soft handoff area (SHA) by adapting the weights of all the assigned human-oriented rules with Sugeno´s fuzzy inference model. The inputs for the fuzzy process are the number of remaining channels of the base station (CHrm) and the number of active sets´ pilots for each mobile station (noBS). The outputs are the new values of soft handoff (SHO) thresholds (T_ADD, T_DROP) of the mobile station. In addition, adaptive SHO thresholds using the classic gradient descent method are also proposed. The results show that for certain values of assigned TRE in SHA with a given erlang traffic load, TRE can be controlled to be close to a certain defined value with errorsin range of 7%. The proposed algorithm is also compared with the case of SHO using the fuzzy inference system (FIS SHO) with no control, IS-95A SHO and IS-95B SHO
Keywords :
cellular radio; code division multiple access; fuzzy logic; fuzzy set theory; gradient methods; telecommunication control; FIS SHO; IS-95A SHO; IS-95B SHO; SHA; SHO thresholds; TRE; active set; base station; erlang traffic; fuzzy inference; fuzzy logic; fuzzy process; gradient descent method; mobile station; trunk-resource-efficiency-controlling soft handoff; Base stations; Communication system traffic control; Control systems; Electronic mail; Error correction; Fuzzy control; Fuzzy logic; Fuzzy sets; Fuzzy systems; Telecommunication traffic;
Conference_Titel :
Vehicular Technology Conference, 2001. VTC 2001 Spring. IEEE VTS 53rd
Conference_Location :
Rhodes
Print_ISBN :
0-7803-6728-6
DOI :
10.1109/VETECS.2001.944544