Method and apparatus for improving data transmission reliability in a wireless communications system

摘要

Techniques for performing duplicate detection and re-ordering for a HARQ transmission are described. For duplicate detection, a receiver determines whether a decoded packet x for an ARQ channel y is a duplicate packet based on packet x and a prior decoded packet for ARQ channel y. For re-ordering, the receiver determines whether an earlier packet is still pending on any other ARQ channel based on prior decoded packets for the ARQ channels and forwards packet x only if there are no pending earlier packets. There are no pending earlier packets on another ARQ channel z if (1) a decoded packet was received on ARQ channel z at a designated time or later or (2) a decoded packet was not received on ARQ channel z within a time window from current time.

主权项

1. A method of performing duplicate detection for a hybrid automatic repeat request (HARQ) transmission, comprising:
decoding a current subpacket received on an ARQ channel from a transmitter to obtain a decoded packet or an erased packet for the ARQ channel; if the decoded packet is obtained for the ARQ channel, determining whether the decoded packet is a duplicate packet based on a match of an identifier of the current subpacket received from the transmitter and a receiver unexpected next identifier generated by a receiver in response to a last subpacket received from the transmitter for a prior decoded packet obtained for the ARQ channel and previously acknowledged; and if the current subpacket is erased, incrementing the receiver unexpected next identifier if the receiver unexpected next identifier is a non-valid value, and forgoing incrementing when the non-valid value is the maximum number of subpackets for each packet.