Transmission with restrictions in unlicensed spectrum

Abstract

Systems, devices, and methods for operating in an unlicensed band are disclosed herein. In one example, a device may receive configuration information that includes a maximum channel occupancy time (MCOT) and a plurality of parameters including a plurality of transmission opportunity windows (TOWs). Based on the configuration information, the device may split a transmission into a plurality of bursts that may be grouped into sets of bursts based on how many bursts fit within a TOW. The number of bursts in a set of bursts may be less than or equal to the MCOT. The device may perform a clear channel assessment (CCA) to determine if the channel is busy and to determine a start time within the TOW for the bursts. The device may then transmit the set of bursts for that TOW, where each burst may have a burst indicator (BI).

1 . A method for operating in an unlicensed band, comprising:
 receiving configuration information that includes a maximum channel occupancy time (MCOT) and a plurality of parameters, wherein the plurality of parameters includes a plurality of transmission opportunity windows (TOWs);   splitting a transmission into a plurality of bursts based on the configuration information;   performing a clear channel assessment (CCA);   determining a start time in a first TOW of the plurality of TOWs for a first set of bursts based on the CCA and the configuration information, wherein each set of bursts comprises one or more bursts of the plurality of bursts;   determining a number of bursts for the first set of bursts based on the configuration information and the start time, wherein the number of bursts of the first set of bursts is less than or equal to the MCOT and fits into the first TOW; and   transmitting the first set of bursts at the start time for the first set of bursts with a burst indicator (BI) for each burst of the number of bursts.   
     
     
         2 . The method of  claim 1 , further comprising performing CCA prior to sending the first set of bursts. 
     
     
         3 . The method of  claim 1 , further comprising scrambling a reference signal (RS) with each of the BIs, wherein a density of the RS is a function of a coverage enhancement level. 
     
     
         4 . The method of  claim 1 , wherein the TOW is a grant of consecutive subframes. 
     
     
         5 . The method of  claim 1 , wherein the transmission is an uplink transmission. 
     
     
         6 . The method of  claim 1 , wherein the configuration information is received on a control channel. 
     
     
         7 . The method of  claim 1 , wherein the one or more BIs is specific to a channel, C-RNTI, a hybrid-ARQ process ID, or a cell. 
     
     
         8 . An apparatus for operating in an unlicensed band, the apparatus comprising:
 a transceiver;   a processor operatively connected to the transceiver, the processor and transceiver configured to receive configuration information that includes a maximum channel occupancy time (MCOT) and a plurality of parameters, wherein the plurality of parameters includes a plurality of transmission opportunity windows (TOWs);   the processor and transceiver further configure to split a transmission into a plurality of bursts based on the configuration information, perform a clear channel assessment (CCA), and determining a start time in a first TOW of the plurality of TOWs for a first set of bursts based on the CCA and the configuration information, wherein each set of bursts comprises one or more bursts of the plurality of bursts; and   the processor and transceiver further configured to determine a number of bursts for the first set of bursts based on the configuration information and the start time, wherein the number of bursts of the first set of bursts is less than or equal to the MCOT and fits into the first TOW, and transmit the first set of bursts at the start time for the first set of bursts with a burst indicator (BI) for each burst of the number of bursts.   
     
     
         9 . The apparatus of  claim 8 , further comprising performing CCA prior to sending the first set of bursts. 
     
     
         10 . The apparatus of  claim 8 , further comprising scrambling a reference signal (RS) with each of the BIs, wherein a density of the RS is a function of a coverage enhancement level. 
     
     
         11 . The apparatus of  claim 8 , wherein the TOW is a grant of consecutive subframes. 
     
     
         12 . The apparatus of  claim 8 , wherein the transmission is an uplink transmission. 
     
     
         13 . The apparatus of  claim 8 , wherein the configuration information is received on a control channel. 
     
     
         14 . The apparatus of  claim 8 , wherein each BI is specific to a channel, C-RNTI, a hybrid-ARQ process ID, or a cell.