In a mobile radio communication system, performance of inter-cell handoff algorithm is critical to the overall grade-of-service of the system. In this thesis, sequential handoff algorithms based on Wald's procedure are being proposed for improving the handoff performance in terms of handoff delay and number of drop calls. The decision on handoff is based upon sequential observations, instead of one decision per observation. Conventional algorithms with fixed signal averaging interval and/or fixed hysteresis level lack of flexibility under changing mobile environment. Unlike conventional algorithms which make binary decisions on 'handoff' or 'no-handoff', the sequential algorithm introduced an additional decision option : 'no-handoff but accumulate'. With this decision option, the mobile...[ Read more ]

In a mobile radio communication system, performance of inter-cell handoff algorithm is critical to the overall grade-of-service of the system. In this thesis, sequential handoff algorithms based on Wald's procedure are being proposed for improving the handoff performance in terms of handoff delay and number of drop calls. The decision on handoff is based upon sequential observations, instead of one decision per observation. Conventional algorithms with fixed signal averaging interval and/or fixed hysteresis level lack of flexibility under changing mobile environment. Unlike conventional algorithms which make binary decisions on 'handoff' or 'no-handoff', the sequential algorithm introduced an additional decision option : 'no-handoff but accumulate'. With this decision option, the mobile unit will initiate a handoff only if the accumulated sequential samples have sufficient confidence to support such decision. The sequential handoff algorithm is shown to improve the handoff performance by reducing the number of drop calls and handoff delay significantly.