Devices and method using transmit power control and scheduling for LTE unlicensed band operation

• US 9,961,646 B2
• Filed: 08/21/2015
• Issued: 05/01/2018
• Est. Priority Date: 08/21/2014
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel IP Corporation (Intel Corporation)
• Inventors: Jeon, Jeongho, Niu, Huaning, Han, Seunghee, Kwon, Hwan-Joon
• Primary Examiner(s): Ferguson, Keith
• Application Number:
  US15/327,167
• Publication Number:
  US 20170164301A1
• Time in Patent Office: 984 Days
• Field of Search: 455522, 455 69, 455509, 455450, 455501, 455 6711, 4554522, 4551271-1273, 4555501, 455423-425, 455434, 455454, 455515, 455561, 4555611, 4554561-457, 4554221, 455403, 4554261, 4554262, 370328, 370329, 370338, 370252
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 52/143 Downlink power control
• 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 52/262 taking into account adaptive modulation and coding [AMC] scheme AMC per se H04L1/0001
• CPC Class Codes: H04W 52/267 taking into account the information rate
• CPC Class Codes: H04W 52/281 taking into account user or data type priority
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/38 TPC being performed in particular situations
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

An enhanced NodeB (eNB), user equipment (UE) and communication methods therebetween using an unlicensed channel of an unlicensed band are generally described. The eNB measures an interference power level (IPL) of the unlicensed channel at the eNB and determine a transmit power level (TPL) for a downlink transmission based on the IPL, the TPL decreasing with increasing IPL. Feedback including unlicensed channel conditions measured by the UE is used by the eNB to determine the UE-eNB proximity. The eNB determines whether to transmit the downlink transmission to the UE based on the IPL and the proximity; as the IPL increases, the eNB services increasingly proximate UEs until, when the IPL exceeds a predetermined threshold, the eNB does not service any UE using the unlicensed channel. The eNB schedules and transmits the downlink transmission to the UE using the transmit power level.

Claims

1. An apparatus of an enhanced NodeB (eNB) comprising:

a transceiver arranged to communicate with a user equipment (UE) over an unlicensed channel in an unlicensed band; and

processing circuitry arranged to;

measure an interference power level within the unlicensed channel;

determine proximity of the UE to the eNB;

determine a transmit power level for a downlink transmission using the unlicensed channel from the eNB to the UE based on the interference power level;

schedule the downlink transmission to the UE dependent on the proximity; and

configure the transceiver to transmit the downlink transmission to the UE using the transmit power level according to the schedule.

2. The apparatus of claim 1, wherein:

the transmit power level is inversely proportional to the interference power level such that the transmit power level decreases with increasing interference power level and increases with decreasing interference power level.

3. The apparatus of claim 2, wherein at least one of:

the transmit power level is determined by P=max(P_max−

cI,

     0), where P_max is a maximum supported transmit power, I is the interference power level and c is a positive constant, and

the transmit power is determined by P=min(P_max/cI, P_max), where P_max is the maximum supported transmit power, I is the interference power level and c is a positive constant.

4. The apparatus of claim 3, wherein:

different maximum supported transmit powers are allocated to different unlicensed carriers used by the eNB for downlink transmissions.

5. The apparatus of claim 2, wherein:

the transmit power is set to zero when the interference power level exceeds a maximum interference power level threshold.

6. The apparatus of claim 1, wherein:

the processing circuitry is further arranged to measure the interference power level from energy detection of the unlicensed channel.

7. The apparatus of claim 1, wherein:

the processing circuitry is further arranged to measure the interference power level from signal preamble detection of valid Wireless Local Area Network (WLAN) Orthogonal frequency-division multiplexing (OFDM) waveforms of the unlicensed channel.

8. The apparatus of claim 1, wherein:

the processing circuitry is further arranged to distinguish individual signals from a superposition of multiple signals, and the interference power level is the interference power level of a strongest signal of the unlicensed channel.

9. The apparatus of claim 1, wherein:

the interference power level is an aggregate energy of a subset of all signals detected by the eNB.

10. The apparatus of claim 1, wherein:

the transceiver is arranged to receive feedback from the UE on the unlicensed channel, and

the processing circuitry is arranged to determine the proximity between the UE and eNB based on the feedback.

11. The apparatus of claim 10, wherein:

the transceiver is arranged to receive an update if the feedback deviates a predetermined amount from a previously received feedback.

12. The apparatus of claim 1, wherein:

the transceiver is arranged to communicate with a plurality of UEs over at least one unlicensed channel in the unlicensed band,

for each UE, the processing circuitry is arranged to measure an interference power level of an unlicensed channel associated with the UE, determine a transmit power level for downlink transmissions from the eNB to the UE based on the interference power level associated with the UE, determine proximity between the UE and eNB based on feedback from the UE on the unlicensed channel, and schedule a downlink transmission to the UE using the transmit power level and dependent on the proximity.

13. The apparatus of claim 12, wherein:

the scheduling and transmission of downlink transmissions to the plurality of UEs employs a proportional relationship between interference power level and proximity to the eNB such that with increasing interference power level the downlink transmissions are limited to UEs with increasing proximity to the eNB.

14. The apparatus of claim 12, wherein:

the scheduling and transmission of downlink transmissions to the plurality of UEs is limited to UEs having a channel quality that supports a minimum Modulation and Coding Scheme (MCS) level at the transmit power level.

15. The apparatus of claim 12, wherein the processing circuitry is arranged to:

estimate an instantaneous achievable rate at each of the UEs based on the feedback from the UE on channel quality between the eNB and the UE and the interference power level at the UE, and

schedule downlink transmissions to the plurality of UEs dependent on the instantaneous achievable rate of the plurality of UEs.

16. The apparatus of claim 1, further comprising:

an antenna configured to transmit communications between the transceiver and the UE.

17. An apparatus of a user equipment (UE) comprising:

a transceiver configured to communicate with an enhanced NodeB (eNB) using an unlicensed channel of an unlicensed band; and

processing circuitry configured to;

configure the transceiver to receive a request for feedback from the eNB;

in response to the request, measure channel quality of the unlicensed channel and configure the transceiver to transmit the feedback indicating the channel quality to the UE, the feedback further comprising information to permit the eNB to determine a proximity of the UE to the eNB; and

configure the transceiver to receive, dependent on the feedback, a downlink transmission from the eNB, the downlink transmission having a transmit power level dependent on an interference power level within the unlicensed channel at the eNB, reception of the downlink transmission by the UE dependent on the interference power level and proximity to the eNB as indicated by the feedback.

18. The apparatus of claim 17, wherein:

the transmit power level is inversely proportional to the interference power level such that the transmit power level decreases with increasing interference power level and increases with decreasing interference power level.

19. The apparatus of claim 17, wherein:

the transceiver is arranged to transmit a feedback update if the measured channel quality deviates a predetermined amount from an immediately preceding measured channel quality.

20. The apparatus of claim 17, wherein:

the transceiver is arranged to continue to automatically transmit feedback updates unless a feedback termination request is received from the eNB.

21. The apparatus of claim 17, wherein:

the channel quality comprises at least one of a reference signal received power (RSRP) or a reference signal received quality (RSRQ).

22. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of an enhanced NodeB (eNB) to configure the eNB to communicate via a transceiver with a user equipment (UE) using an unlicensed channel of an unlicensed band, the one or more processors to configure the eNB to:

determine a transmit power level for a downlink transmission from the eNB to the UE based on an interference power level at the eNB within the unlicensed channel;

determine proximity of the UE from the eNB using channel quality feedback received from the UE;

determine whether or not to transmit the downlink transmission to the UE based on the interference power level and the proximity; and

in response to determining to transmit the downlink transmission, transmit the downlink transmission to the UE using the transmit power level.

23. The non-transitory computer-readable storage medium of claim 22, wherein the one or more processors configure the eNB to:

receive at least one feedback update automatically from the UE, the at least one feedback update comprising a channel quality that deviates a predetermined amount from a channel quality of immediately preceding feedback received from the UE,

determine whether or not continued feedback updates are desired from the UE, and

in response to determining that continued feedback updates are no longer desired, transmit a feedback termination request to the UE.

24. The non-transitory computer-readable storage medium of claim 22, wherein:

the transmit power level is inversely proportional to the interference power level such that the transmit power level decreases with increasing interference power level and increases with decreasing interference power level.

25. An apparatus of a user equipment (UE) comprising:

a transceiver configured to communicate with an enhanced NodeB (eNB) using an unlicensed channel of an unlicensed band; and

processing circuitry configured to;

receive a request for feedback from the eNB;

in response to the request, measure channel quality of the unlicensed channel and configure the transceiver to transmit the feedback indicating the channel quality to the UE; and

configure the transceiver to receive, dependent on the feedback, a downlink transmission from the eNB, the downlink transmission having a transmit power level dependent on an interference power level within the unlicensed channel at the eNB,

wherein the transmit power level is inversely proportional to the interference power level such that the transmit power level decreases with increasing interference power level and increases with decreasing interference power level.

26. The apparatus of claim 25, wherein:

the transceiver is arranged to transmit a feedback update if the measured channel quality deviates a predetermined amount from an immediately preceding measured channel quality.