Methods and apparatus for directional channel sensing for beamformed transmissions

1 . A method for directional channel sensing, the method comprising:

determining, by a wireless communication device, a first sensing beam requirement for a first subset of transmission beams;

determining, by the wireless communication device, a first sensing beam and a first scale factor so that the first sensing beam covering the first subset of transmission beams satisfies the first sensing beam requirement scaled by the first scale factor, the first sensing beam being selected from a set of candidate sensing beams;

performing, by the wireless communication device, a first Clear Channel Assessment (CCA) using the first sensing beam and a first energy detection threshold (EDT), the first EDT determined in accordance with the first scale factor;

determining a second sensing beam requirement for a second subset of transmission beams;

determining a second sensing beam and a second scale factor so that the second sensing beam covering the second subset of transmission beams satisfies the second sensing beam requirement scaled by the second scale factor, the second sensing beam being selected from the set of candidate sensing beams; and

performing a second CCA using the second sensing beam and a second EDT, the second EDT determined in accordance with the second scale factor.

2 . The method of claim 1 , wherein the first sensing beam requirement is that an X dB beamwidth of the first sensing beam includes each direction belonging to a Y dB beamwidth of the first subset of transmission beams, X and Y being configurable parameters.

3 . The method of claim 1 , wherein the first sensing beam requirement is that a gain of the first sensing beam measured in a direction is larger than a threshold, the direction determined in accordance with the first subset of transmission beams, the threshold determined in accordance with the first sensing beam and the first subset of transmission beams.

4 . The method of claim 3 , further comprising:

determining a Max-hold Effective Isotropic Radiated Power (EIRP), the Max-hold EIRP being a pointwise maximum of EIRPs of the first subset of transmission beams.

5 . The method of claim 4 , wherein the direction is a peak direction of the Max-hold EIRP, and wherein the threshold is X dB of a peak of the Max-hold EIRP, X being a configurable parameter.

6 . The method of claim 4 , wherein the direction is determined such that the Max-hold EIRP measured in the direction is larger than X dB of a peak of the Max-hold EIRP, and wherein the threshold is Y dB of the Max-hold EIRP measured in the direction, X and Y being configurable parameters.

7 . The method of claim 4 , wherein the direction is determined such that the Max-hold EIRP measured in the direction is larger than X dB of a peak of the Max-hold EIRP, and wherein the threshold is Y dB of a peak gain of the first sensing beam, X and Y being configurable parameters.

8 . The method of claim 3 , further comprising determining a composite transmit angular power profile (APP), the composite transmit APP being an envelope of APPs of the first subset of transmission beams,

wherein the direction is determined such that the composite transmit APP measured in the direction is larger than X dB of a peak of the composite transmit APP,

and wherein the threshold is Y dB of the composite transmit APP measured in the direction divided by the peak of the composite transmit APP, X and Y being configurable parameters.

9 . The method of claim 1 , wherein in response to no sensing beam in the set of candidate sensing beams satisfying the first sensing beam requirement without scaling by the first scale factor, the first sensing beam requirement scaled by the first scale factor is that a gain of the first sensing beam measured in a direction is larger than a threshold multiplied by the first scale factor.

10 . The method of claim 9 , wherein the first scale factor is a largest positive value such that at least one sensing beam in the set of candidate sensing beams satisfies the first sensing beam requirement scaled by the first scale factor, and wherein the first sensing beam is selected from the at least one sensing beam.

11 . The method of claim 1 , wherein in response to at least one sensing beam in the set of candidate sensing beams satisfying the first sensing beam requirement, the first sensing beam requirement scaled by the first scale factor is the same as the first sensing beam requirement, the first scale factor being 1 and the first sensing beam being selected from the at least one sensing beam.

12 . A wireless communication device comprising:

a non-transitory memory storage comprising instructions; and

one or more processors in communication with the non-transitory memory storage, wherein the one or more processors execute the instructions to perform:

determining a first sensing beam requirement for a first subset of transmission beams;

determining a first sensing beam and a first scale factor so that the first sensing beam covering the first subset of transmission beams satisfies the first sensing beam requirement scaled by the first scale factor, the first sensing beam being selected from a set of candidate sensing beams;

performing a first Clear Channel Assessment (CCA) using the first sensing beam and a first energy detection threshold (EDT), the first EDT determined in accordance with the first scale factor;

determining a second sensing beam requirement for a second subset of transmission beams;

determining a second sensing beam and a second scale factor so that the second sensing beam covering the second subset of transmission beams satisfies the second sensing beam requirement scaled by the second scale factor, the second sensing beam being selected from the set of candidate sensing beams; and

performing a second CCA using the second sensing beam and a second EDT, the second EDT determined in accordance with the second scale factor.

13 . The wireless communication device of claim 12 , wherein the first sensing beam requirement is that an X dB beamwidth of the first sensing beam includes each direction belonging to a Y dB beamwidth of the first subset of transmission beams, X and Y being configurable parameters.

14 . The wireless communication device of claim 12 , wherein the first sensing beam requirement is that a gain of the first sensing beam measured in a direction is larger than a threshold, the direction determined in accordance with the first subset of transmission beams, the threshold determined in accordance with the first sensing beam and the first subset of transmission beams.

15 . The wireless communication device of claim 14 , wherein the one or more processors further execute the instructions to perform:

determining a Max-hold Effective Isotropic Radiated Power (EIRP), the Max-hold EIRP being a pointwise maximum of EIRPs of the first subset of transmission beams.

16 . The wireless communication device of claim 15 , wherein the direction is a peak direction of the Max-hold EIRP, and wherein the threshold is X dB of a peak of the Max-hold EIRP, X being a configurable parameter.

17 . The wireless communication device of claim 15 , wherein the direction is determined such that the Max-hold EIRP measured in the direction is larger than X dB of a peak of the Max-hold EIRP, and wherein the threshold is Y dB of the Max-hold EIRP measured in the direction, X and Y being configurable parameters.

18 . The wireless communication device of claim 15 , wherein the direction is determined such that the Max-hold EIRP measured in the direction is larger than X dB of a peak of the Max-hold EIRP, and wherein the threshold is Y dB of a peak gain of the first sensing beam, X and Y being configurable parameters.

19 . The wireless communication device of claim 14 , wherein the one or more processors further execute the instructions to determine a composite transmit angular power profile (APP), the composite transmit APP being an envelope of APPs of the first subset of transmission beams,

wherein the direction is determined such that the composite transmit APP measured in the direction is larger than X dB of a peak of the composite transmit APP,

and wherein the threshold is Y dB of the composite transmit APP measured in the direction divided by the peak of the composite transmit APP, X and Y being configurable parameters.

20 . The wireless communication device of claim 12 , wherein in response to no sensing beam in the set of candidate sensing beams satisfying the first sensing beam requirement without scaling by the first scale factor, the first sensing beam requirement scaled by the first scale factor is that a gain of the first sensing beam measured in a direction is larger than a threshold multiplied by the first scale factor.

21 . The wireless communication device of claim 20 , wherein the first scale factor is a largest positive value such that at least one sensing beam in the set of candidate sensing beams satisfies the first sensing beam requirement scaled by the first scale factor, and wherein the first sensing beam is selected from the at least one sensing beam.

22 . The wireless communication device of claim 12 , wherein in response to at least one sensing beam in the set of candidate sensing beams satisfying the first sensing beam requirement, the first sensing beam requirement scaled by the first scale factor is the same as the first sensing beam requirement, the first scale factor being 1 and the first sensing beam being selected from the at least one sensing beam.

23 . A non-transitory computer-readable medium having instructions stored thereon that, when executed by an apparatus, cause the apparatus to perform operations for directional channel sensing, the operations comprising:

determining a first sensing beam requirement for a first subset of transmission beams;

determining a first sensing beam and a first scale factor so that the first sensing beam covering the first subset of transmission beams satisfies the first sensing beam requirement scaled by the first scale factor, the first sensing beam being selected from a set of candidate sensing beams;

performing a first Clear Channel Assessment (CCA) using the first sensing beam and a first energy detection threshold (EDT), the first EDT determined in accordance with the first scale factor;

determining a second sensing beam requirement for a second subset of transmission beams;

determining a second sensing beam and a second scale factor so that the second sensing beam covering the second subset of transmission beams satisfies the second sensing beam requirement scaled by the second scale factor, the second sensing beam being selected from the set of candidate sensing beams; and

performing a second CCA using the second sensing beam and a second EDT, the second EDT determined in accordance with the second scale factor.