Channel access indication for spectral reuse, power savings and coexistence

Abstract

A Channel Access Indicator (CAI) may be employed in New Radio Unlicensed (NR-U) to indicate channel occupation by a node to nodes outside its cell, indicate channel occupation by a node to nodes within its cell to aid spectral reuse, and to trigger a handshake between nodes within a cell to ensure that receiver has clear channel to transmit and receive.

We claim: 
     
         1 . An apparatus, comprising a processor, a memory, and communication circuitry, the apparatus being connected to a network via its communication circuitry, the apparatus further comprising computer-executable instructions stored in the memory of the apparatus which, when executed by the processor of the apparatus, cause the apparatus to perform operations comprising:
 receiving a channel access indicator (CAI) from a radio network access point (gNB), the CAI indicating the remaining channel occupancy time (COT) of a transmitter; and   monitoring, upon reception of the CAI and for at least the duration of the remaining COT, a set of control signals, the control signals being for downlink and uplink grants.   
     
     
         2 . The apparatus of  claim 1 , wherein, the CAI further comprises:
 a duration of the remaining COT; and optionally   a bandwidth of channel occupancy; and/or   a spatial direction of channel occupation.   
     
     
         3 . The apparatus of  claim 1 , wherein the CAI is received in:
 a preamble;   a reference signal (RS);   a downlink control information (DCI);   the preamble and the DCI; or   the RS and the DCI.   
     
     
         4 . The apparatus of  claim 1 , wherein the CAI is received in a multicast DCI. 
     
     
         5 . That apparatus of  claim 4 , wherein the CAI is received in a group-common DCI. 
     
     
         6 . The apparatus of the  claim 1 , wherein the CAI is received from in a DCI that is broadcast by the transmitter. 
     
     
         7 . The apparatus of the  claim 1 , wherein the CAI is received in a UE-specific DCI. 
     
     
         8 . The apparatus of the  claim 1 , wherein the operations further comprise receiving multiple CAIs from the transmitter within the COT. 
     
     
         9 . An apparatus, comprising a processor, a memory, and communication circuitry, the apparatus being connected to a network via its communication circuitry, the apparatus further comprising computer-executable instructions stored in the memory of the apparatus which, when executed by the processor of the apparatus, cause the apparatus to perform operations comprising:
 sending one or more channel access indicators (CAIs) within a channel access opportunity, the CAIs indicating the remaining channel occupancy time (COT) for that channel access.   
     
     
         10 . The apparatus of  claim 9 , wherein, the first CAI further comprises:
 a bandwidth of channel occupancy; or   a spatial direction of channel occupation.   
     
     
         11 . The apparatus of  claim 9 , wherein the one or more CAIs are transmitted in:
 a preamble;   a reference signal (RS);   a downlink control information (DCI);   the RS and the DCI; or   the preamble and the DCI.   
     
     
         12 . The apparatus of  claim 9 , wherein the one or more CAIs are multicast by the apparatus. 
     
     
         13 . The apparatus of  claim 12 , wherein the one or more CAIs are multicast by the apparatus as group-common DCIs. 
     
     
         14 . The apparatus of  claim 9 , wherein the one or more CAIs are broadcast by the apparatus. 
     
     
         15 . An apparatus, comprising a processor, a memory, and communication circuitry, the apparatus being connected to a network via its communication circuitry, the apparatus further comprising computer-executable instructions stored in the memory of the apparatus which, when executed by the processor of the apparatus, cause the apparatus to perform operations comprising:
 transmitting, upon a successful channel access and from a first available symbol within a channel occupancy time (COT), a physical uplink shared channel (PUSCH); and   providing, to a receiver and following the successful channel access, a channel access indicator (CAI), the CAI indicating a starting symbol of the PUSCH.   
     
     
         16 . The apparatus of  claim 15 , wherein, the first available symbol is selected from a set of pre-configured symbols, the set of pre-configured symbols being provided through RRC signaling to the first equipment. 
     
     
         17 . The apparatus of  claim 15 , wherein, a set of scheduled PUSCH resources for which channel access is not available, is punctured. 
     
     
         18 . The apparatus of  claim 15 , wherein, the CAI is provided via a demodulation reference signal (DMRS) of the PUSCH. 
     
     
         19 . The apparatus of  claim 18 , wherein, the operations further comprise power boosting the DMRS for a first PUSCH transmission following channel occupancy. 
     
     
         20 . The apparatus of  claim 18 , wherein, the operations further comprise modifying a location of the DMRS within a grant according to a starting location of the PUSCH.