Method for determining hand-off candidates in a neighbor set in a CDMA communication system

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) A communication system provides wireless communication in a coverage area and includes a plurality of base stations and at least a mobile station.
The plurality of base stations transmit at least a corresponding plurality of pilot signals.
The mobile station receive at least one of the plurality of pilot signals and transmits a message which includes a list of a plurality of candidate pilot signals for a hand-off routine.
The list of candidate pilot signals is determined, according to one aspect of the present invention, by a method including a step of finding a location of the mobile station in the coverage area, and a step of determining the list of the plurality of candidate pilot signals according to the location of the mobile station.
More particularly, in a code division multiple access communication system, the Pilot Strength Measurement Message which is transmitted by a mobile station contains four sets of candidate lists.
The sets are ordered in a predetermined priority.
The first priority set is called the Active Set.
The base station candidates listed in the Active Set have already a forward traffic channel assigned to the mobile station.
The second highest priority set is the Candidate Set.
The candidate list in the Candidate Set are those cells and sectors which their pilot signals have been received by the mobile station with sufficient strength to indicate that an associated forward link will successfully be demodulated.
The third highest priority set is the Neighbor Set.
The candidate list in the Neighbor Set are those cells and sectors that the strength of their pilot signals indicated that the associated traffic channel is likely to be demodulated.
The list in the Neighbor Set excludes the candidates lists in the Active and Candidate Sets.
The forth or the last priority set is the Remaining Set.
The Remaining Set contains a list of all possible pilots in the communication system excluding the lists contained in the Active, Candidate and Neighbor Sets