Transmit power reduction for a high speed CDMA link in soft handoff
First Claim
1. A method of controlling handoff in a communication system in which data is transmitted to a subscriber unit by providing a first subset of said data on at least one fundamental channel and a second subset of said data on at least one supplemental channel, the method comprising:
- receiving pilot strength measurement messages from said subscriber unit;
selecting a plurality of base stations for providing transmissions to said subscriber unit on said at least one fundamental channel based on said pilot strength measurement messages;
selecting at least one of said plurality of base stations for providing transmissions to said subscriber unit on said at least one supplemental channel; and
transmitting to said subscriber unit an extended handoff direction message indicating the identities of said plurality of base stations for communication of said first subset of data and indicating the identity of said at least one of said plurality of base stations for communication of said second subset of data;
wherein signaling data is carried only on said at least one fundamental channel.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and apparatus for controlling the transmit power of a high rate code division multiple access (CDMA) link is described. The channel condition to a subscriber unit is evaluated and the configuration of a high rate link in soft handoff is based on the channel condition. If a fading channel is detected the supplemental channels of the high rate link are transmitted from multiple base stations. If a non-fading channel is detected the supplemental channels of the high rate link are transmitted from a single base station. Parameters monitored to determine the channel condition include the pilot strength, pilot code offset and error rate.
154 Citations
14 Claims
-
1. A method of controlling handoff in a communication system in which data is transmitted to a subscriber unit by providing a first subset of said data on at least one fundamental channel and a second subset of said data on at least one supplemental channel, the method comprising:
-
receiving pilot strength measurement messages from said subscriber unit; selecting a plurality of base stations for providing transmissions to said subscriber unit on said at least one fundamental channel based on said pilot strength measurement messages; selecting at least one of said plurality of base stations for providing transmissions to said subscriber unit on said at least one supplemental channel; and transmitting to said subscriber unit an extended handoff direction message indicating the identities of said plurality of base stations for communication of said first subset of data and indicating the identity of said at least one of said plurality of base stations for communication of said second subset of data; wherein signaling data is carried only on said at least one fundamental channel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A method of controlling handoff in a communication system in which data is transmitted to a subscriber unit by providing a first subset of said data on a fundamental channel and a second subset of said data on at least one supplemental channel, the method comprising:
-
receiving pilot strength measurement messages from said subscriber unit; selecting a plurality of base stations for providing transmissions to said subscriber unit on said fundamental channel based on said pilot strength measurement messages; and selecting at least one of said plurality of base stations for providing transmissions to said subscriber unit on said at least one supplemental channel; wherein said step of independently selecting at least one of said plurality of base stations comprises; determining whether said subscriber unit is stationary; and selecting a base station corresponding to the strongest pilot signal in said pilot strength measurement messages as said at least one of said plurality of base stations when said subscriber unit is determined to be stationary. - View Dependent Claims (14)
-
Specification