Patent ID: 7676731
Filing Date: 2010-03-09
Classification: H04L

Abstract:
1. A method for retransmitting coded bits by a transmitter in response to a retransmission request from a receiver in a mobile communication system, the method comprising the steps of: selecting a modulation technique to be used at retransmission as a modulation technique having a lower modulation order than a modulation technique used at initial transmission; selecting a puncturing pattern according to requirements of a HARQ (Hybrid Automatic Repeat Request) type; puncturing the coded bits using the selected puncturing pattern; selecting as many coded bits as the number of coded bits that are to be symbol-mapped by the selected modulation technique, among the punctured coded bits; verifying if a packet is a retransmission packet, and if the packet is a retransmission packet, setting the amount of data to be retransmitted to be less than the amount of data transmitted in an initial transmission; symbol-mapping the selected coded bits by the selected modulation technique; and transmitting the symbol-mapped coded bits to the receiver, wherein the coded bits are output from an encoder at an initial transmission, and wherein a coding rate at retransmission is equal to a coding rate at initial transmission.