Wake up signal configurations for wireless communications

Patent metadata

Field	Value
Publication number	US-10959175-B2
Application number	US-201816224679-A
Country	US
Kind code	B2
Filing date	Dec 18, 2018
Priority date	Dec 21, 2017
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

Methods, systems, and devices for wireless communications are described. A wireless device, such as a user equipment (UE), may receive a wakeup signal (WUS) from a network node, such as a base station, before listening for a paging message. The UE may assume a maximum duration (Wmax) for the WUS based on a dependency on variables associated with the base station and WUS. In some cases, the UE may determine not to monitor a WUS for the Wmax and may engage in an early termination based on the determination. That is, the UE may monitor the WUS for a time shorter than Wmax. The UE may assume the shorter time has a dependency on variables associated with the base station and WUS. The base station may indicate this dependency to the UE either implicitly or explicitly.

First claim

What is claimed is:

1. A method for wireless communications, comprising:
receiving, from a base station, an indication of a scaling factor associated with a wakeup signal (WUS), wherein the scaling factor is based at least on a WUS transmission characteristic;
receiving, from the base station and for a WUS time duration, the WUS in accordance with the WUS transmission characteristic, wherein the WUS time duration is based at least on the scaling factor and an associated control channel repetition parameter; and
monitoring a downlink channel from the base station for scheduling information based at least on the received WUS, wherein the scheduling information comprises information for a paging message from the base station.

2. The method of claim 1 , further comprising:
receiving, from the base station, an indication of the WUS time duration.

3. The method of claim 1 , further comprising:
determining a WUS reception duration based at least on a signal quality of a reference signal and a probability of detection threshold, wherein the WUS reception duration is less than the WUS time duration.

4. The method of claim 3 , wherein the WUS reception duration is determined based at least on the WUS transmission characteristic.

5. The method of claim 3 , further comprising:
receiving the reference signal from the base station; and
measuring the signal quality of the reference signal.

6. The method of claim 1 , wherein receiving the indication of the scaling factor comprises:
receiving a system information block (SIB) that comprises the indication of the scaling factor, a value of the scaling factor, or a combination thereof.

7. The method of claim 6 , further comprising:
receiving a power offset parameter for the WUS in the SIB.

8. The method of claim 7 , further comprising:
determining that no higher layer signaling has been received to configure a power ratio;
wherein the power offset parameter comprises a fixed power ratio between a narrowband reference signal and the WUS.

9. The method of claim 7 , further comprising:
determining that no higher layer signaling has been received to configure a power ratio;
wherein the power offset parameter comprises a fixed power ratio between a cell-specific reference signal and the WUS, and wherein the WUS is associated with machine type communication (MTC).

10. The method of claim 1 , further comprising:
determining a maximum WUS time duration based at least on a ratio of a maximum repetition of an associated control channel and the scaling factor, wherein the WUS time duration is based at least on the maximum WUS time duration, and wherein the associated control channel repetition parameter corresponds to a maximum number of repetitions of an associated narrowband control channel for paging.

11. The method of claim 1 , further comprising:
receiving, from the base station, an indication of a transmit diversity dimension for transmission of the WUS.

12. The method of claim 11 , wherein the transmit diversity dimension is determined by a number of antennas switching on one antenna port every two subframes or by a number of antenna ports switching on all antenna ports every two subframes.

13. The method of claim 1 , wherein the WUS time duration is determined based at least on a predetermined maximum WUS time duration.

14. The method of claim 1 , wherein the WUS transmission characteristic comprises a WUS transmit power, a WUS transmit diversity scheme, an indication of a legacy synchronization signal detection before WUS reception, a power ratio between the WUS and a narrowband reference signal, a maximum coupling loss (MCL) associated with the UE, or a combination thereof.

15. The method of claim 1 , wherein a signal to noise ratio (SNR) is determined based at least on a power ratio between the WUS and a narrowband reference signal, and wherein a single port SNR is estimated for the WUS based at least on the SNR.

16. The method of claim 1 , wherein the scaling factor is based at least in part on a transmit diversity scheme that includes a pattern index of fixed patterns, with each pattern defining a number of fixed basic units and a transmit diversity dimension, or includes the number of fixed basic units and the transmit diversity dimension.

17. The method of claim 16 , wherein the fixed basic units comprise subframes, 1 millisecond transmission time intervals (TTIs), slots, or mini-slots.

18. The method of claim 1 , further comprising:
receiving a maximum number of repetitions of narrowband control channel transmissions in a system information block (SIB), wherein the WUS time duration is determined based at least on the maximum number of repetitions of the narrowband control channel transmissions.

19. The method of claim 1 , wherein further comprising:
determining an early termination duration based at least on a target signal to noise ratio (SNR) or a maximum coupling loss (MCL) associated with the UE, wherein the WUS time duration is based at least on the early termination duration.

20. A method for wireless communications, comprising:
transmitting an indication of a scaling factor associated with a wakeup signal (WUS) to a user equipment (UE), wherein the scaling factor is determined based at least on a WUS transmission characteristic; and
transmitting, to the UE and for a WUS time duration, the WUS in accordance with the WUS transmission characteristic, wherein the WUS time duration is determined based at least on the scaling factor and an associated control channel repetition parameter.

21. The method of claim 20 , further comprising:
transmitting, to the UE, an indication of the WUS time duration, wherein the WUS time duration is based at least on a target signal to noise ratio (SNR) or a maximum coupling loss (MCL) associated with the UE.

22. The method of claim 20 , further comprising:
transmitting, to the UE, a reference signal, wherein the WUS time duration is based at least on a signal quality of the reference signal and a probability of detection threshold.

23. The method of claim 22 , wherein the reference signal comprises a narrowband reference signal or a cell-specific reference signal.

24. The method of claim 20 , wherein transmitting the indication of the scaling factor comprises:
transmitting a system information block (SIB) that comprises the indication of the scaling factor, a value of the scaling factor, or a combination thereof.

25. The method of claim 24 , wherein the SIB further comprises a power offset parameter that indicates a power ratio between a narrowband reference signal and the WUS.

26. The method of claim 20 , further comprising:
transmitting, to the UE, an indication of a transmit diversity dimension for transmission of the WUS.

27. The method of claim 26 , further comprising:
determining the transmit diversity dimension based at least in part on a number of antennas switching on one antenna port every two subframes or a number of antenna ports switching on all antenna ports every two subframes.

28. The method of claim 20 , wherein the WUS time duration is determined based at least on a predetermined maximum WUS time duration.

29. The method of claim 20 , wherein the WUS transmission characteristic comprises a WUS transmit power, a WUS transmit diversity scheme, an indication of a legacy synchronization signal detection of the

Assignees

• Qualcomm Inc

Inventors

• Liu Le
• Rico Alvarino Alberto

Classifications

• Y02D30/70

  in wireless communication networks · CPC title

• H04W52/246

  where the output power of a terminal is based on a path parameter calculated in said terminal · CPC title

• H04W52/248

  where transmission power control commands are generated based on a path parameter · CPC title

• H04W52/325

  Power control of control or pilot channels · CPC title

• H04W52/146

  Uplink power control · CPC title