Soft handoff algorithm and wireless communication system for third generation cdma systems

Abstract

A method and apparatus for providing an improved soft handoff algorithm in a wireless communication system for third generation code division multiple access (“CDMA”) systems. The method comprises establishing communication between the wireless communication device and the at least one serving base station, the at least one serving base station having a list of at least one neighboring base station which neighbors the respective serving base station, monitoring the reverse channel signal strength at the wireless communication device from at least one neighboring base station, transmitting to a base station controller the wireless communication device signal strength detected at each neighboring base station, compiling at the base station controller a list of effective neighboring base stations from the at least one neighboring base station based on the monitored wireless communication device signal strength, transmitting the list of effective neighboring base stations to each at least one serving base station, periodically transmitting a neighboring base station list update message to the wireless communication device, the neighboring base station list update message including the effective neighboring base station list, storing the effective neighboring base station list as a neighbor set in the wireless communication device, performing forward channel signal strength searching of the neighbor set in the wireless communication device after storing the effective neighbor list as the neighbor set, and monitoring the signals from the effective neighboring base stations to accomplish a handoff between the at least one service base station and the receiving neighboring base station.