Method and apparatus for channel access switch in a wireless communication system

Abstract

Methods and apparatuses are provided for channel access switching in a wireless communication system, with or without Listen-Before-Talk (LBT), and/or with different types of efficiently operated LBT. A device, including a User Equipment (UE) or a base station, can determine whether and/or how to perform LBT for a transmission based on a property of the transmission. The property could be a resource allocation for the transmission. The property could be a way to allocate resources for the transmission. The property could be a length or size of resource allocated for the transmission. The property could be an amount of resources allocated for the transmission. The resource allocation could be a time domain resource allocation and/or a frequency domain resource allocation.

What is claimed is: 
     
         1 . A method for a base station operating in a shared spectrum, comprising:
 transmitting a first Channel State Information Reference Signal (CSI-RS) outside discovery burst, on a first resource on a channel after sensing the channel, if the first CSI-RS is outside discovery burst on the first resource that is indicated by Downlink Control Information (DCI), and wherein the CSI-RS and the DCI are on a same cell; and   transmitting a second CSI-RS within discovery burst, on a second resource on the channel without sensing the channel, if the second CSI-RS is within discovery burst on the second resource that is indicated by a Radio Resource Control (RRC) configuration for discovery burst.   
     
     
         2 . The method of  claim 1 , further comprising transmitting the first CSI-RS on the channel after sensing the channel if the first CSI-RS is transmitted outside discovery burst on the first resource. 
     
     
         3 . The method of  claim 1 , further comprising transmitting the second CSI-RS on the channel without sensing the channel if the second CSI-RS is transmitted within discovery burst on the second resource. 
     
     
         4 . The method of  claim 1 , further comprising not performing Listen-Before-Talk (LBT) for the second CSI-RS transmission on the second resource. 
     
     
         5 . The method of  claim 1 , further comprising performing LBT for the first CSI-RS transmission on the first resource. 
     
     
         6 . The method of  claim 1 , wherein the first resource is on a serving cell. 
     
     
         7 . The method of  claim 1 , wherein the second resource is on a serving cell. 
     
     
         8 . A method for a base station operating in a shared spectrum, comprising:
 performing Listen-Before-Talk (LBT) for a first Channel State Information Reference Signal (CSI-RS) transmission, outside discovery burst, on a first resource if the first CSI-RS is outside discovery burst on the first resource that is indicated by Downlink Control Information (DCI), and wherein the CSI-RS and the DCI are on a same cell; and   not performing LBT for a second CSI-RS within discovery burst on a second resource if the second CSI-RS is within discovery burst on the second resource that is indicated by a Radio Resource Control (RRC) configuration for discovery burst.   
     
     
         9 . The method of  claim 8 , further comprising performing LBT for the first CSI-RS if the first CSI-RS is transmitted outside discovery burst on the first resource. 
     
     
         10 . The method of  claim 8 , further comprising not performing LBT for the second CSI-RS if the second CSI-RS is transmitted within discovery burst on the second resource. 
     
     
         11 . The method of  claim 8 , wherein the first resource is on a serving cell. 
     
     
         12 . The method of  claim 8 , wherein the second resource is on a serving cell. 
     
     
         13 . A base station configured to operate in a shared spectrum, comprising:
 a memory; and   a processor operatively coupled with the memory, wherein the processor is configured to execute program code to:
 transmit a first Channel State Information Reference Signal (CSI-RS) outside discovery burst, on a first resource on a channel after sensing the channel, if the first CSI-RS is outside discovery burst on the first resource that is indicated by Downlink Control Information (DCI), and wherein the CSI-RS and the DCI are on a same cell; and 
 transmit a second CSI-RS within discovery burst on a second resource on the channel without sensing the channel if the second CSI-RS is within discovery burst on the second resource that is indicated by a Radio Resource Control (RRC) configuration for discovery burst. 
   
     
     
         14 . The base station of  claim 13 , wherein the processor is further configured to execute program code to transmit the first CSI-RS on the channel after sensing the channel if the first CSI-RS is transmitted within discovery burst on the first resource. 
     
     
         15 . The base station of  claim 13 , wherein the processor is further configured to execute program code to transmit the second CSI-RS on the channel without sensing the channel if the second CSI-RS is transmitted within discovery burst on the second resource. 
     
     
         16 . The base station of  claim 13 , wherein the processor is further configured to execute program code to not perform Listen-Before-Talk (LBT) for the second CSI-RS transmission on the second resource. 
     
     
         17 . The base station of  claim 13 , wherein the processor is further configured to execute program code to perform LBT for the first CSI-RS transmission on the first resource. 
     
     
         18 . The base station of  claim 13 , wherein the first resource is on a serving cell. 
     
     
         19 . The base station of  claim 13 , wherein the second resource is on a serving cell. 
     
     
         20 . The base station of  claim 13 , wherein the channel is a carrier, or a part of a carrier, consisting of a contiguous set of resource blocks (RBs).