Method and apparatus for adaptive indirect carrier modulation

1. A method for operation by a wireless transmit/receive unit, WTRU, the method comprising:

selecting a constellation from a set of constellations corresponding to a symbol configuration for indirect carrier modulation, ICM, based on at least one constellation performance efficacy indicator, each constellation performance efficacy indicator respectively corresponding to a constellation of the set of constellations; and

using the selected constellation, simultaneously harvesting energy and transmitting data.

2. The method of claim 1 , further comprising evaluating at least one of the constellation performance efficacy indicators based on downlink energy harvesting, DL EH, efficiency and uplink, UL, data transfer reliability for the corresponding constellation.

3. The method of claim 2 , further comprising measuring a received signal strength and the downlink energy harvesting efficiency.

4. The method of claim 2 , wherein a constellation performance efficacy indicator comprises at least one quantity of ηRISS, PICM and ETX and wherein the constellation is selected in a manner that the at least one quantity comprised in the constellation performance efficacy indicator satisfies a respective condition ηRISS>εPICM <θ, and ETX>Δ where η is the energy harvesting efficiency, RISS is the measured received signal strength, PICM is a power consumption of the ICM, ETX is an uplink transmitted energy per symbol and θ, ε, and Δ are goal values.

5. The method of claim 4 , wherein the constellation is selected in a manner that (ηRISS−PICM)(N/R) >δ and a second efficacy indicator ETX>Δ, where N is an uplink data packet size, R is an uplink data rate and δ is a goal value.

6. The method of claim 1 , further comprising selecting the symbol configuration.

7. The method of claim 1 , further comprising transmitting an indication of the selected constellation and symbol configuration.

8. The method of claim 1 , wherein the constellation defines an arrangement of constellation points.

9. The method of claim 1 , wherein the symbol configuration defines a number of bits per symbol.

10. The method of claim 1 , wherein the constellation is determined by indirect carrier modulator impedance states.

11. A wireless transmit/receive unit, WTRU, comprising:

an antenna;

an energy harvester; and

at least one hardware processor configured to select a constellation from a set of constellations corresponding to a symbol configuration for indirect carrier modulation, ICM, based on at least one constellation performance efficacy indicator, each constellation performance efficacy indicator respectively corresponding to a constellation of the set of constellations;

wherein the selected constellation is used to simultaneously harvest energy using the energy harvester and transmit data using the antenna.

12. The WTRU of claim 11 , wherein the at least one hardware processor is further configured to evaluate at least one of the constellation performance efficacy indicators based on downlink energy harvesting, DL EH, efficiency and uplink, UL, data transfer reliability for the corresponding constellation.

13. The WTRU of claim 12 , wherein the at least one hardware processor is further configured to measure a received signal strength and the downlink energy harvesting efficiency.

14. The WTRU of claim 12 , wherein a constellation performance efficacy indicator comprises at least one quantity of ηRISS, PICM and ETX and wherein the at least one hardware processor is configured to select the constellation in a manner that the at least one quantity comprised in the constellation performance efficacy indicator satisfies a respective condition ηRISS >ε, PICM<θ, and ETX>Δ, where η is the energy harvesting efficiency, RISS is the measured received signal strength, PICM is a power consumption of the ICM, ETX is an uplink transmitted energy per symbol and θ, ε, and Δ are goal values.

15. The WTRU of claim 14 , wherein the at least one hardware processor is configured to select the constellation in a manner that (ηRISS−PICM)(N/R)>δ and a second efficacy indicator ETX>Δ, where N is an uplink data packet size, R is an uplink data rate and δ is a goal value.

16. The WTRU of claim 11 , wherein the at least one hardware processor is further configured to select the symbol configuration.

17. The WTRU of claim 11 , wherein the at least one hardware processor is further configured to transmit, through the antenna, an indication of the selected constellation and symbol configuration.

18. The WTRU of claim 11 , wherein the constellation defines an arrangement of constellation points.

19. The WTRU of claim 11 , wherein the symbol configuration defines a number of bits per symbol.

20. The WTRU of claim 11 , wherein the constellation is determined by indirect carrier modulator impedance states.