Using an uplink grant as trigger of first or second type of CQI report

Patent metadata

Field	Value
Publication number	US-11516837-B2
Application number	US-202016784725-A
Country	US
Kind code	B2
Filing date	Feb 7, 2020
Priority date	Mar 19, 2007
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

Channel state feedback is provided from a UE to a base station as a first, detailed or a second, less detailed type of channel state feedback information. Initially it is determined whether the UE has received an uplink grant from the base station or not. If the UE has received an uplink grant, a first type of channel state feedback information is transmitted to the base station on the granted resource. If, however, the UE has not received an uplink grant, a second type of channel state feedback information is transmitted to the base station. Different types of channel state feedback information enables a UE and an associated to base station to use available resources more efficiently, when requesting for and delivering channel state feedback information.

First claim

The invention claimed is:

1. A method in a user equipment (UE) providing channel state feedback information from the UE to a base station, comprising the steps of:
determining whether the UE has received an uplink grant from the base station or not;
transmitting a first type of channel state feedback information to the base station on a granted resource associated with the uplink grant when the UE has received an uplink grant;
transmitting a second type of channel state feedback information on a dedicated resource when the UE has not received an uplink grant, wherein said second type of information is less detailed than the first type.

2. The method according to claim 1 , further comprising the step of determining whether channel state feedback trigger criteria specified for said UE is valid and wherein the respective channel state feedback information is transmitted only when said channel state feedback trigger criteria is valid.

3. The method according to claim 1 , wherein when the UE has no uplink grant the second, less detailed type of channel state feedback information is periodically transmitted while the more detailed first type of channel state feedback information is periodically transmitted when the UE does have an uplink grant.

4. The method according to claim 1 , further comprising the step of determining whether the UE has uplink data and when the UE has uplink data and an uplink grant a scheduled uplink transmission will consist of both channel state feedback information and uplink data.

5. The method according to claim 1 , further comprising the step of determining whether the UE has uplink data and when an uplink grant but no uplink data is present a scheduled uplink transmission will consist of only channel state feedback information.

6. The method according to claim 5 , wherein said scheduled uplink transmission is utilized as a signaling of an empty buffer status information to the base station.

7. The method according to claim 5 , wherein said scheduled uplink transmission is utilized as an acknowledgement of the uplink grant that was transmitted in the downlink.

8. The method according to claim 1 , wherein the type of report to be used for transmission of the respective channel state feedback information is dependent on the size of the received uplink grant.

9. The method according to claim 8 , further comprising the step of comparing the size of said uplink grant to a threshold (T 1 ) and wherein the channel state feedback information is transmitted in a report of a first type of a size associated with T 1 when said uplink grant size exceeds T 1 .

10. The method according to claim 9 , wherein when said size does not exceed T 1 , said comparison is gradually repeated for one or more thresholds, T 2 . . . Tn, wherein T 1 >T 2 >Tn and wherein a match results in the transmission of a report of an associated size.

11. The method according to claim 1 , wherein the size of the uplink grant is an indication of the bandwidth, the modulation size, and/or the code rate associated with the uplink grant.

12. The method according to claim 1 , wherein remaining available energy for data transmission is included on the uplink as a condition for transmission of the channel state feedback information.

13. A user equipment (UE) for providing channel state feedback information from the UE to a base station, the UE comprising:
processing circuitry configured to:
determine whether the UE has received an uplink grant from the base station or not;
transmit a first type of channel state feedback information to the base station on a granted resource associated with the uplink grant when the UE has received an uplink grant; and
transmit a second type of channel state feedback information on a dedicated resource when the UE has not received an uplink grant, wherein said second type of information is less detailed than the first type.

14. The UE according to claim 13 , wherein said processing circuitry is further configured to determine whether relevant channel state feedback trigger criteria specified for said UE is valid or not and wherein said processing circuitry is configured to only transmit channel state feedback information when also said channel state feedback trigger criteria is valid.

15. The UE according to claim 13 , wherein said channel state feedback information is transmitted in a generated report.

16. The UE according to claim 15 , wherein said processing circuitry is further configured to periodically generate a second, less detailed report type when the UE has no uplink grant and a second, more detailed report type when the UE does have an uplink grant.

17. The UE according to claim 13 , wherein said processing circuitry is further configured to compare the size of said uplink grant to a threshold (T 1 ) and generate a report associated with T 1 when said size exceeds T 1 .

18. The UE according to claim 17 , wherein when said size does not exceed T 1 , said processing circuitry is further configured to gradually repeat said comparison procedure for one or more thresholds, T 2 . . . Tn, wherein T 1 >T 2 . . . >Tn, and wherein said processing circuitry is further configured to transmit a report of an associated size when a comparison match.

19. The UE according to claim 13 , wherein said processing circuitry is further configured to include remaining available energy for data transmission on the uplink as a condition for generating said report.

20. A method in a base station comprising a scheduler for obtaining channel state feedback from a user equipment (UE), the method comprising:
generating an uplink grant in case channel state feedback of a first type is required; and
providing a generated uplink grant to the UE in order to receive the channel state feedback on a granted resource associated with the uplink grant;
wherein the channel state feedback of said first type is more detailed than a channel state feedback of a second type that is received from the UE on a dedicated resource.

21. The method according to claim 20 , wherein said determining step further comprises determining when downlink data is present in the base station and when downlink data is present, generating and providing an uplink grant to the UE in order to receive downlink channel state feedback on the granted resource.

22. The method according to claim 21 , wherein said determining step further comprises determining whether an uplink load is below a threshold (th), and when the uplink load is below said threshold, generating and providing an uplink grant to the UE.

23. The method according to claim 20 , wherein an uplink grant is provided to the UE for the purpose of receiving an uplink transmission on the granted resource containing at least channel state feedback, and wherein the uplink transmission from the UE is used for estimating the uplink channel quality for link adaptation and/or channel dependent scheduling of uplink data from the UE.

24. The method according to claim 20 , wherein an uplink grant is provided to the UE for the purpose of maintaining uplink synchronization.

25. The method according to claim 20 , wherein the size of the uplink grant is variable.

26. A base station comprising a scheduler for obtaining channel state feedback from a user equipment (UE), the base station comprising:
processing circuitry configured to:
generate an uplink grant in order to receive channel state feedback of a

Assignees

• Ericsson Telefon Ab L M

Inventors

• Englund Eva
• Frenger Pål
• Parkvall Stefan

Classifications

• H04W72/542

  using measured or perceived quality · CPC title

• H04W72/23 Primary

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04L1/0026 Primary

  Transmission of channel quality indication · CPC title

• H04L1/0027

  Scheduling of signalling, e.g. occurrence thereof · CPC title

• H04W88/02

  Terminal devices · CPC title