US 7,321,780 B2
Enhanced uplink rate selection by a communication device during soft handoff
Robert T. Love, Barrington, Ill. (US); Amativa Ghosh, Buffalo Grove, Ill. (US); Ravi Kuchibhotla, Gurnee, Ill. (US); and Nicholas W. Whinnett, Marlborough (United Kingdom)
Assigned to Motorola, Inc., Schaumburg, Ill. (US)
Filed on Apr. 30, 2003, as Appl. No. 10/427,361.
Prior Publication US 2004/0219920 A1, Nov. 04, 2004
Int. Cl. H04M 1/00 (2006.01); H04Q 7/20 (2006.01)
U.S. Cl. 455—522  [455/442] 2 Claims
OG exemplary drawing
 
1. A method for rate selection by a communication device for uplink during soft handoff in a communication system, the method comprising steps of:
receiving a scheduling assignment message including a power margin limit from a scheduler;
determining a data rate for an uplink transmission during soft handoff using the power margin limit, local channel conditions and a buffer occupancy of the communication device; and
transmitting to a serving base station on an uplink channel at the data rate determined from the determining step;
wherein the determining step includes a data rate constraint of
K2*Pmarginlimit/Pdpcch*TPC_correction
where Pmarginlimit is the power margin limit, Pdpcch is a power of the downlink physical control channel, and K2 is a scale factor, and TPC_correction dependent upon a power control command history and pilot channel signal strength.