Techniques for Supporting Relay Operation in Wireless Communication Systems

Abstract

Techniques for supporting operation of relay stations in wireless communication systems are described. In an aspect, a bitmap may be sent by a base station and/or a relay station to identify subframes of at least two types in multiple radio frames. For example, the bitmap may indicate whether each subframe covered by the bitmap is of a first type or a second type. UEs may use the bitmap to control their operation. For example, a UE may perform channel estimation or measurement for the subframes of the first type and may skip channel estimation and measurement for the subframes of the second type. In another aspect, a base station may transmit data and/or control information on resources not used by a relay station to transmit a reference signal. This may avoid interference to the reference signal from the relay station, which may improve performance for UEs communicating with the relay station.

What is claimed is: 
     
         1 . A method for wireless communication, comprising:
 performing channel estimation or measurement for subframes of a first type; and   skipping channel estimation and measurement for subframes of a second type different from the first type.   
     
     
         2 . The method of  claim 1 , further comprising:
 receiving a bitmap identifying the subframes of the first type and the subframes of the second type.   
     
     
         3 . The method of  claim 1 , further comprising:
 receiving the subframes of the first type time division multiplexed with the subframes of the second type.   
     
     
         4 . The method of  claim 1 , wherein the subframes of the first type include a reference signal, and wherein the channel estimation or measurement is performed based on the reference signal. 
     
     
         5 . The method of  claim 1 , wherein the subframes of the first type and the subframes of the second type are designated by a base station. 
     
     
         6 . The method of  claim 1 , wherein the subframes of the first type comprise regular subframes and the subframes of the second type comprise multicast/broadcast single frequency network (MBSFN) subframes. 
     
     
         7 . An apparatus for wireless communication, comprising:
 means for performing channel estimation or measurement for subframes of a first type; and   means for skipping channel estimation and measurement for subframes of a second type different from the first type.   
     
     
         8 . The apparatus of  claim 7 , further comprising:
 means for receiving a bitmap identifying the subframes of the first type and the subframes of the second type.   
     
     
         9 . The apparatus of  claim 7 , wherein the subframes of the first type include a reference signal, and wherein the channel estimation or measurement is performed based on the reference signal. 
     
     
         10 . A method for wireless communication, comprising:
 identifying resources not used by a relay station to transmit a reference signal; and   sending control information, or data, or both by a base station on the identified resources.   
     
     
         11 . The method of  claim 10 , wherein the identified resources comprise at least one orthogonal frequency division multiplexing (OFDM) symbol in a data portion of a multicast/broadcast single frequency network (MBSFN) subframe. 
     
     
         12 . The method of  claim 10 , wherein the identified resources comprise at least one resource block in a data portion of a multicast/broadcast single frequency network (MBSFN) subframe. 
     
     
         12 . An apparatus for wireless communication, comprising:
 means for identifying resources not used by a relay station to transmit a reference signal; and   means for sending control information, or data, or both by a base station on the identified resources.   
     
     
         13 . The apparatus of  claim 12 , wherein the identified resources comprise at least one orthogonal frequency division multiplexing (OFDM) symbol in a data portion of a multicast/broadcast single frequency network (MBSFN) subframe. 
     
     
         14 . The apparatus of  claim 12 , wherein the identified resources comprise at least one resource block in a data portion of a multicast/broadcast single frequency network (MBSFN) subframe. 
     
     
         15 . A method for wireless communication, comprising:
 determining a subframe reserved for a first station; and   sending no transmissions in the reserved subframe by a second station to allow the first station to communicate with one or more other stations in the reserved subframe.   
     
     
         16 . The method of claim  156 , wherein the first station is a relay station, the second station is a base station, and the one or more other stations are one or more user equipments (UEs). 
     
     
         17 . The method of claim  156 , wherein the first station is a base station, the second station is a relay station, and the one or more other stations are one or more user equipments (UEs). 
     
     
         18 . An apparatus for wireless communication, comprising:
 means for determining a subframe reserved for a first station; and   means for sending no transmissions in the reserved subframe by a second station to allow the first station to communicate with one or more other stations in the reserved subframe.   
     
     
         19 . The apparatus of  claim 18 , wherein the first station is a relay station, the second station is a base station, and the one or more other stations are one or more user equipments (UEs). 
     
     
         20 . The apparatus of  claim 18 , wherein the first station is a base station, the second station is a relay station, and the one or more other stations are one or more user equipments (UEs).