Patent ID: 6157628
Filing Date: 2000-12-05
Classification: H04B,H04L

Abstract:
A retransmission control method for a CDMA mobile communication system in which a user data is unidirectionally transmitted in packets from a sending side to a receiving side between a base station and a plurality of mobile stations, said method comprising the steps of:(a) establishing a plurality of forward and backward channels in pairs each assigned for communication between said base station and one of said plurality of mobile stations and each assigned a different spread code;(b) dividing each of said packets into a plurality of frames at said sending side;(c) transmitting said frames from said sending side to said receiving side through said forward channels;(d) upon each receipt of one frame, transmitting from said receiving side to said sending side through said backward channels, a backward control signal that indicates whether or not said one frame has been received correctly at said receiving side, said backward control signals being transmitted at different transmission timings to avoid overlap of transmissions thereof on said backward channels; and(e) retransmitting, from said sending side to said receiving side through said forward channels, a frame that said backward control signal indicates has not been received correctly at said receiving side.