Downlink association set for uplink ACK/NACK in time division duplex system

摘要

In a Time Division Duplex (TDD) system, downlink and uplink communications share the same bandwidth but occupy different subframes. When the downlink has more subframes than the uplink, special treatment on user equipment (UE) ACK/NACK feedback is needed. One uplink may need to ACK multiple downlink subframes. A downlink association without unnecessary ACK/NACK resources sets accounts for subframes for which ACK feedback is not desired. Examples of such subframes include: a blank subframe; an almost blank subframe where only a cell specific Reference Signal (RS) is transmitted; a Time Division Multiplex (TDM) partition in which an evolved NodeB (eNB) only transmits a Physical Downlink Shared Channel (PDSCH) or a Physical Downlink Control Channel (PDCCH) indicating Semi-persistent scheduling (SPS) at certain downlink subframes; a Downlink Pilot Timeslot (DwPTS) with a certain special subframe configuration where an eNB does not send the PDSCH and the UE is not in SPS active mode in the DwPTS; and a Multi-Media Broadcast over a Single Frequency Network (MBSFN) subframe when the UE is not in SPS active mode in the MBSFN subframe.

主权项

1. A method for defining a downlink and uplink subframe association
in a wireless communication system, the method comprising:
determining a feedback association associating a subframe acknowledgement in an uplink subframe with a plurality of downlink subframes;determining at least one downlink subframe of the plurality of downlink subframes, which does not require subframe acknowledgement, the at least one determined downlink subframe being a downlink subframe not containing a Physical Downlink Control Channel (PDCCH) indicating Semi-Persistent Scheduling (SPS) release; andmodifying the feedback association by discounting the at least one determined downlink subframe of the plurality downlink subframes from processing, to thereby prevent the at least one discounted downlink subframe from affecting the subframe acknowledgement,the acknowledgement being based on at least one undiscounted subframe of the plurality of subframes.