Power Control For LTE Deployment In Unlicensed Band

• US 20130343288A1
• Filed: 06/21/2012
• Published: 12/26/2013
• Est. Priority Date: 06/21/2012
• Status: Active Grant

• Current Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Original Assignee: Nokia Corporation, Nokia Solutions and Networks US LLC (Nokia Corporation)
• Inventors: Ratasuk, Rapeepat, Uusitalo, Mikko Aleksi, Sorri, Antti S., Iraji, Sassan, Mangalvedhe, Nitin
• Granted Patent: US 9,031,017 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04L 5/0098 Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 52/228 using past power values or information
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 52/38 TPC being performed in particular situations
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 72/1215 for collaboration of different radio technologies
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

Methods of power control for LTE transmissions in unlicensed bands are described. One method includes determining, at a first device (such as a LTE UE or LTE eNB), a scheduled transmission window for a LTE transmission in an unlicensed band. The transmission window indicates a time for sending the transmission in the unlicensed band. Prior to the scheduled transmission window, the method also includes determining whether a WiFi transmitter is transmitting a signal in the unlicensed band. The method also includes, in response to determining that the transmitter is transmitting in the unlicensed band, determining an adjusted transmission power for the transmission and sending the transmission (such as from an LTE UE to an LTE eNB or from an LTE eNB to an LTE UE) in the transmission window at the adjusted transmission power. Apparatus and computer readable media are also described.

Claims

1. A method comprising:

determining, at a first device, a scheduled transmission window for a transmission of an evolved universal terrestrial radio access network system operating in an unlicensed band, where the transmission window indicates a time for sending the transmission in the unlicensed band;

prior to the scheduled transmission window, determining, by the first device, whether a transmitter is transmitting a signal in the unlicensed band, where the transmitter is separate from the evolved universal terrestrial radio access network system; and

in response to determining that the transmitter is transmitting in the unlicensed band, determining an adjusted transmission power for the transmission and sending, from the first device to a second device, the transmission in the transmission window at the adjusted transmission power.

2. The method of claim 1, where the transmitter is one of:

a WiFi access point and a WiFi mobile device.

3. The method of claim 1, where determining the scheduled transmission window comprising receiving an allocation of the transmission window.

4. The method of claim 3, where receiving the allocation of the transmission window comprises receiving the allocation of the transmission window on a primary component carrier in a licensed band.

5. The method of claim 1, where the transmission is a secondary component carrier transmission.

6. The method of claim 1, where determining the adjusted transmission power is based on at least one of:

historic information of the transmitter;

measured interference level;

path loss information;

location information of the first device; and

location information of the transmitter.

7. The method of claim 1, further comprising determining channel status information of the signal, where determining the adjusted transmission power is based at least in part on the channel status information.

8. The method of claim 7, where determining the channel status information comprises determining at least one of a rate of the signal;

a modulation of the signal;

a coding scheme of the signal; and

a path loss of the signal.

9. The method of claim 8, further comprising sending the channel status information to the second device.

10. The method of claim 1, further comprising:

determining whether an authorization has been received, where the authorization indicates to send the transmission in the transmission window using the adjusted transmission power when the transmitter is determined to be transmitting the signal in the unlicensed band; and

in response to not receiving the authorization and determining that the transmitter is transmitting in the unlicensed band, preventing sending the transmission in the transmission window.

11. The method of claim 1, determining whether an authorization has been received, where the authorization indicates to send the transmission in the transmission window using the adjusted transmission power when the transmitter is determined to be transmitting the signal in the unlicensed band;

and

in response to receiving the authorization and determining that the transmitter is transmitting in the unlicensed band, determining whether to send the transmission in the transmission window,

where determining whether to send the transmission in the transmission window is based at least in part on at least one of;

channel status information of the signal, network provided information, and a random calculation.

12. The method of claim 1, further comprising receiving an uplink grant, where the uplink grant comprises a field and where the field indicates a power control formula to use when determining the adjusted transmission power.

13. An apparatus, comprising at least one processor;

and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following;

to determine a scheduled transmission window for a transmission of an evolved universal terrestrial radio access network system operating in an unlicensed band, where the transmission window indicates a time for sending the transmission in the unlicensed band;

prior to the scheduled transmission window, to determine whether a transmitter is transmitting a signal in the unlicensed band, where the transmitter is separate from the evolved universal terrestrial radio access network system; and

in response to determining that the transmitter is transmitting in the unlicensed band, to determine an adjusted transmission power for the transmission and to send, to a second apparatus, the transmission in the transmission window at the adjusted transmission power.

14. The apparatus of claim 13, where, when determining the scheduled transmission window, the at least one memory and the computer program code are further configured to cause the apparatus to receive an allocation of the transmission window on a primary component carrier in a licensed band and where the transmission is a secondary component carrier transmission.

15. The apparatus of claim 13, where the at least one memory and the computer program code are further configured to cause the apparatus to determine channel status information of the signal, where determining the adjusted transmission power is based at least in part on the channel status information.

16. A computer readable medium tangibly encoded with a computer program executable by a processor to perform actions comprising:

determining, at a first device, a scheduled transmission window for a transmission of an evolved universal terrestrial radio access network system operating in an unlicensed band, where the transmission window indicates a time for sending the transmission in the unlicensed band;

prior to the scheduled transmission window, determining, by the first device, whether a transmitter is transmitting a signal in the unlicensed band, where the transmitter is separate from the evolved universal terrestrial radio access network system; and

in response to determining that the transmitter is transmitting in the unlicensed band, determining an adjusted transmission power for the transmission and sending, from the first device to a second device, the transmission in the transmission window at the adjusted transmission power.

17. The computer readable medium of claim 16, where determining the scheduled transmission window comprises receiving an allocation of the transmission window on a primary component carrier in a licensed band and where the transmission is a secondary component carrier transmission.

18. The computer readable medium of claim 16, where the actions further comprise determining channel status information of the signal, where determining the adjusted transmission power is based at least in part on the channel status information.

19. A method comprising:

allocating a plurality of transmission windows to a plurality of mobile devices of an LTE system operating in an unlicensed band, where the transmission window indicates a time for sending a transmission in the unlicensed band;

determining whether to authorize individual mobile devices of the plurality of mobile devices are to send the associated transmission in the transmission window using an adjusted transmission power when a transmitter is determined to be transmitting a signal in the unlicensed band; and

sending, to each mobile device, an indication of a transmission window allocating to the mobile device and whether the mobile device is authorized to send the associated transmission in the transmission window using an adjusted transmission power when a transmitter is determined to be transmitting a signal in the unlicensed band.

20. The method of claim 19, where determining whether to authorize individual mobile devices comprises, for each individual mobile device, determining an expected level of interference to be experienced by a receiver receiving the signal, where the interference is caused by the individual mobile device sending the associated transmission in the transmission window and the plurality of mobile devices is prioritized based on the expected level of interference.