Passive IoT illumination power setting

Abstract

An apparatus 70 comprising: means for receiving a proximity pathloss threshold from a network, wherein a pathloss between a passive device 102 and a user equipment 10, UE, is less than the proximity p

Claims

1. An apparatus comprising:means for receiving a proximity pathloss threshold from a network, wherein a pathloss between a passive device and a user equipment connected to the apparatus is less than the proximity pathloss threshold;means for receiving, from the user equipment, at least one reference signal received power measurement associated with the user equipment;means for receiving, from the user equipment, a report that indicates a beam of the user equipment having a higher reference signal received power than at least one other beam of the user equipment;means for determining a backscatter link beam direction for a transmit or receive beam for a backscatter link with the passive device, based on a direction of the beam of the user equipment having a higher reference signal received power than at least one other beam of the user equipment; andmeans for determining an illumination power of an illumination transmission to the passive device, based at least on the proximity pathloss threshold and the at least one reference signal received power measurement.

2. The apparatus of claim 1, further comprising:means for determining the backscatter link beam direction, based on a reference signal received power of a first beam of the user equipment and a reference signal received power of a neighbor beam of the user equipment;wherein the reference signal received power of the first beam is higher than a reference signal received power of at least one neighbor beam of the user equipment including the neighbor beam.

3. The apparatus of claim 2, further comprising:means for determining whether a distance between the user equipment and an edge of the first beam is less than or equal to a distance threshold; andmeans for determining the backscatter link beam direction, based on the reference signal received power of the first beam of the user equipment and thereference signal received power of the neighbor beam of the user equipment, when the distance between the user equipment and the edge of the first beam is less than or equal to the distance threshold.

4. The apparatus of any of claims 2 to 3, further comprising:means for determining a first angle based on the first beam;means for determining a difference between the reference signal received power of the first beam and the reference signal received power of the neighbor beam;means for determining a correction angle to apply to the first angle, based on the difference; andmeans for determining the backscatter link beam direction, based on the correction angle applied to the first angle;wherein the first angle and the correction angle are in an azimuth domain or an elevation domain.

5. The apparatus of any of claims 2 to 4, further comprising:means for determining a first angle based on the first beam;means for determining location information associated with the user equipment;means for determining a correction angle to apply to the first angle, based on the location information associated with the user equipment; andmeans for determining the backscatter link beam direction, based on the correction angle applied to the first angle;wherein the first angle and the correction angle are in an azimuth domain or an elevation domain.

6. The apparatus of any of claims 1 to 5, further comprising:means for determining a pathloss between the apparatus and the user equipment, based on a reference signal received power of the user equipment;means for determining a pathloss between the apparatus and the passive device, based at least on the pathloss between the apparatus and the user equipment; andmeans for determining the illumination power based at least partially on the pathloss between the apparatus and the passive device.

7. The apparatus of any of claims 1 to 6, further comprising:means for determining a coefficient based on at least one known backscatter link characteristic and a reference signal power density; andmeans for determining the illumination power, based on the coefficient.

8. The apparatus of claim 7, wherein the at least one known backscatter link characteristic comprises at least one of:a sensitivity of a reader of a backscatter signal, oran antenna gain of the passive device, ora backscatter modulation factor.

9. The apparatus of claim 8, further comprising:means for determining the coefficient at least based on the sensitivity of the reader of the backscatter signal, the antenna gain of the passive device, and the backscatter modulation factor.

10. The apparatus of any of claims 7 to 9, further comprising:means for determining a reference signal received power of the user equipment; andmeans for determining the illumination power at least partially based on the reference signal received power.

11. The apparatus of any of claims 1 to 10, further comprising:means for determining, when the passive device has no energy storage, a received power threshold of the passive device, such that a carrier wave arrives at the passive device with a power greater than the received power threshold.

12. The apparatus of claim 11, further comprising:means for determining a first coefficient based on at least one known backscatter link characteristic and a reference signal power density;means for determining a reference signal received power of the user equipment;means for determining a second coefficient based at least on the received power threshold of the passive device and one known backscatter link characteristic; andmeans for determining the illumination power based on the first coefficient, the reference signal received power, and the second coefficient.

13. The apparatus of claim 12, further comprising:means for determining a difference between the first coefficient and the reference signal received power;means for determining the illumination power based on the proximity pathloss threshold added to a larger of the difference and the second coefficient, when the user equipment performs the illumination transmission to the passive device.

14. The apparatus of claim 13, further comprising:means for determining the second coefficient based on an antenna gain of the user equipment and an antenna gain of the passive device, wherein the one known backscatter link characteristic comprises the antenna gain of the passive device.

15. The apparatus of any of claims 12 to 14, further comprising:means for determining a sum comprising the first coefficient added to the proximity pathloss threshold;means for determining the illumination power based on the reference signal received power subtracted from a larger of the sum and the second coefficient, when the apparatus performs the illumination transmission to the passive device.

16. The apparatus of claim 15, further comprising:means for determining the second coefficient based on the reference signal power density, an antenna gain of the user equipment, and an antenna gain of the passive device, wherein the one known backscatter link characteristic comprises the antenna gain of the passive device.

17. The apparatus of any of claims 1 to 16, further comprising:means for storing a used illumination power, a reference signal received powerof a user equipment, and a beam selection of a user equipment in a database; and means for retrieving from the database at least one of: the used illumination power, or the reference signal received power of the user equipment, or the beam selection of the user equipment;wherein the illumination power of the illumination transmission to the passive device is determined based on at least one of the used illumination power, or the reference signal received power of the user equipment, or the beam selection of the user equipment retrieved from the database.

18. The apparatus of claim 17, further comprising:means for determining whether a backscatter signal was received;wherein the used illumination power, or the reference signal received power of the user equipment, or the beam selection of a user equipment is stored in the database when the backscatter signal was received.

19. The apparatus of any of claims 17 to 18, further comprising: means for determining whether the passive device is stationary; wherein the used illumination power, or the reference signal received power of the user equipment, or the beam selection of a user equipment is stored in the database when the passive device is stationary.

Images