Correlator-based carrier sense multiple access

Abstract

The disclosed subject matter is directed towards a clear channel assessment procedure based on a common preamble, such as for use with 3GPP and IEEE 802.11 technologies, or any other radio technology, including for use in the 6 GHz band. Detection of the common preamble is based on detecting known sequences in signal part, which can be detected without decoding the preamble's payload (channel) part to determine an ongoing transmission's duration. If an ongoing transmission is detected, subsequent energy detection monitoring is performed to determine when transmission ends, which can use a different energy detection threshold from what is used in the initial clear channel assessment's energy detection. The technology facilitates the usage of different sampling rates by different radio technologies that work concurrently in the same unlicensed band, by correlating a received preamble with a stored preamble that accounts for deterministic distortions arising from the different sampling rates.

What is claimed is: 
     
         1 . A method, comprising:
 performing, by a network device comprising a processor, a clear channel assessment of a wireless channel to determine whether the wireless channel is clear for use, the clear channel assessment comprising an energy detection followed by a preamble detection, wherein the preamble detection comprises physical carrier sensing for a received waveform and the preamble detection is not based on a data payload carried by the received waveform; and   in response to the clear channel assessment determining that the wireless channel is clear, facilitating, by the network device, transmitting information via the wireless channel.   
     
     
         2 . The method of  claim 1 , wherein the energy detection is a first energy detection, and further comprising, in response to the clear channel assessment determining that the wireless channel is not clear for use, performing, by the network device, a second energy detection, to monitor the wireless channel, that is subsequent to the first energy detection. 
     
     
         3 . The method of  claim 2 , wherein the first energy detection employs a first energy detection threshold as part of determining whether the wireless channel is clear for use, and the second energy detection employs a second energy detection threshold as part of monitoring whether the wireless channel is clear for use that is different from the first energy detection threshold. 
     
     
         4 . The method of  claim 3 , further comprising determining, by the network device, the second energy detection threshold based on a received energy detection level of the received waveform and a received preamble detection level of the received waveform during the clear channel assessment. 
     
     
         5 . The method of  claim 1 , wherein the physical carrier sensing comprises a correlator-based automatic correlation process. 
     
     
         6 . The method of  claim 1 , wherein the physical carrier sensing comprises a correlator-based cross-correlation process. 
     
     
         7 . The method of  claim 1 , wherein the physical carrier sensing employs a preamble detection threshold. 
     
     
         8 . A user equipment, comprising:
 a processor; and   a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, comprising:
 performing a clear channel assessment of a radio channel to determine whether the radio channel is clear for use, the clear channel assessment comprising an energy detection and a preamble detection, wherein the preamble detection comprises physical carrier sensing for a received waveform and does not employ a data payload carried by the received waveform; and 
 in response to the clear channel assessment determining that the radio channel is clear, transmitting signals via the radio channel. 
   
     
     
         9 . The user equipment of  claim 8 , wherein the energy detection is a first energy detection, and wherein the operations further comprise, in response to the clear channel assessment determining that the radio channel is not clear for use, performing a second energy detection to monitor the radio channel, wherein the second energy detection is subsequent to the first energy detection. 
     
     
         10 . The user equipment of  claim 9 , wherein the first energy detection employs a first energy detection threshold, and the second energy detection employs a second energy detection threshold that is different from the first energy detection threshold. 
     
     
         11 . The user equipment of  claim 10 , wherein the operations further comprise determining, by the user equipment, the second energy detection threshold based on a received energy detection level and a received preamble detection level during the clear channel assessment. 
     
     
         12 . The user equipment of  claim 11 , wherein the operations further comprise determining, by the user equipment, the second energy detection threshold as the first energy detection threshold minus a difference of the received energy detection level minus the received preamble detection level. 
     
     
         13 . The user equipment of  claim 8 , wherein the physical carrier sensing comprises a correlator-based automatic correlation process. 
     
     
         14 . The user equipment of  claim 8 , wherein the physical carrier sensing comprises a correlator-based cross-correlation process. 
     
     
         15 . A non-transitory machine-readable medium, comprising executable instructions that, when executed by a processor of a base station, facilitate performance of operations, comprising:
 determining, via a clear channel assessment, whether a wireless channel is clear for use, the clear channel assessment comprising an energy detection and a preamble detection, wherein the preamble detection comprises physical carrier sensing for a received waveform that is independent of a data payload carried by the received waveform; and   in response to the clear channel assessment determining that the wireless channel is clear, transmitting signals via the wireless channel.   
     
     
         16 . The non-transitory machine-readable medium of  claim 15 , wherein the energy detection is a first energy detection, and wherein the operations further comprise, in response to the clear channel assessment determining that the wireless channel is not clear for use, performing a second energy detection to monitor the wireless channel that is subsequent to the first energy detection. 
     
     
         17 . The non-transitory machine-readable medium of  claim 16 , wherein the first energy detection applies a first function with respect to a first energy detection threshold to determine whether the wireless channel is clear for use, and the second energy detection applies a second function with respect to a second energy detection threshold to monitor whether the wireless channel is clear for use, and wherein the second energy detection threshold is different from the first energy detection threshold. 
     
     
         18 . The non-transitory machine-readable medium of  claim 17 , wherein the operations further comprise determining the second energy detection threshold based on a received energy detection level and a received preamble detection level during the clear channel assessment. 
     
     
         19 . The non-transitory machine-readable medium of  claim 18 , wherein the operations further comprise determining the second energy detection threshold as the first energy detection threshold minus a difference of the received energy detection level minus the received preamble detection level. 
     
     
         20 . The non-transitory machine-readable medium of  claim 15 , wherein the physical carrier sensing comprises at least one of a correlator-based automatic correlation process or a correlator-based cross-correlation process.