Methods and Arrangements for Supporting Retransmission

• US 20150155978A1
• Filed: 06/08/2012
• Published: 06/04/2015
• Est. Priority Date: 06/08/2012
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Eriksson, Erik, Hessler, Martin
• Granted Patent: US 9,467,258 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0608 Antenna selection according to transmission parameters
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0814 based on current reception conditions, e.g. switching to different antenna when signal level is below threshold
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 1/1825 Adaptation of specific ARQ protocol parameters according to transmission conditions
• CPC Class Codes: H04L 1/1838 for semi-reliable protocols, e.g. for less sensitive applications such as streaming video buffer level management for video bitstream receiver H04N21/44004
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1864 ARQ related signaling H04L1/1607 takes precedence
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals

Abstract

The herein suggested technology gives principles for how HARQ-feedback, or corresponding, can be predicted using distributed data from scheduling decisions and optionally also from radio measurements. This data can be sent between base stations after the finished scheduling, and does not require a backhaul with very low latency. The predicted HARQ feedback can then be used for scheduling a retransmission or new transmission sooner than the actual HARQ feedback is received.

Claims

1. Method performed by a network node A for supporting retransmission in a wireless communication system comprising a user equipment, UE, which is scheduled, by a base station, BS, C, for communication in a radio resource R, said method comprising:

receiving information on scheduling decisions associated with the radio resource R from at least one BS;

estimating the interference to the communication of the UE in radio resource R based on said information;

predicting whether a retransmission of the UE communication is required, based on the estimated interference and a predetermined criterion.

2. Method according to claim 1, further comprising:

receiving information, from one of the at least one BS, on one or more of;

an estimated path gain or channel-measurements associated with a UE served by the BS;

an estimated path gain to neighboring cells for a UE served by the BS;

an estimated path gain to a UEs heard by the BS;

channel-measurements to a UE heard by the BS;

an estimated decoding success of a UE served by the BS; and

a decoding success of transmissions received, by the BS, from a UE; and

wherein the estimating of the interference is based on said information and the information on scheduling decisions associated with the radio resource R.

3. Method according to claim 1, wherein the predicting involves determining a decoding success probability for the UE communication based on the estimated interference, and wherein the predicting of whether a retransmission of the UE communication is required is based on the estimated decoding success probability and the predetermined criterion.

4. Method according to claim 3, wherein the determining of the decoding success probability involves:

estimating a signal to interference and noise ratio, SINR, for the UE communication in radio resource R; and

mapping said SINR to a success probability using tabulated decoder performance.

5. Method according to claim 1 wherein the predetermined criterion involves a SINR threshold value and/or a block error rate, BLER, threshold value, representing a breakpoint between decoding success and decoding failure.

6. Method according to claim 1, wherein the network node A is the BS C serving the UE.

7. Method according to claim 6, further comprising:

when the prediction indicates that a retransmission is required;

scheduling a retransmission of the UE communication.

19. Computer program, comprising computer readable code means, which when run in a node according to any of claims 10-18 causes the node to perform the corresponding method according to claim 1.

20. Computer program product comprising computer program according to claim 19.

10. Network node A operable in a wireless communication system comprising a user equipment, UE, which is scheduled, by a base station, BS, C, for communication in a radio resource R, said network node A comprising:

a receiver, adapted to receive information on scheduling decisions associated with the radio resource R from at least one BS,

an estimating unit, adapted to estimate the interference to the communication of the UE in radio resource R based on said information,

a predicting unit, adapted to predict whether a retransmission of the UE communication is required, based on the estimated interference and a predetermined criterion.

8. Method performed by a Base Station, BS, B for supporting retransmission in a wireless communication system comprising a user equipment, UE being scheduled, by a BS C, for communication in a radio resource R, and further comprising a network node A according to claim 10, said method comprising

providing information on scheduling decisions made by the BS B to the network node A,

thus enabling the network node A to estimate an interference to the communication of the UE in radio resource R based on said information;

and further to predict whether a retransmission of the UE communication is required, based on the estimated interference and a predetermined criterion.

9. Method according to claim 8, further comprising:

providing information on one or more of;

an estimated path gain or channel-measurements associated with a UE served by the BS B;

an estimated path gain to neighboring cells for a UE served by the BS B;

an estimated path gain to a UE heard by the BS B;

channel-measurements to a UE heard by the BS B;

an estimated decoding success of a UE served by the BS B; and

a decoding success of transmissions received, by the BS B, from a UE.

11. Network node according to claim 10, further adapted to receive information, from one of the at least one BS, on one or more of:

an estimated path gain or channel-measurements associated with a UE served by the BS;

an estimated path gain to neighboring cells for a UE served by the BS;

an estimated path gain to a UEs heard by the BS;

channel-measurements to a UE heard by the BS;

an estimated decoding success of a UE served by the BS; and

a decoding success of transmissions received, by the BS, from a UE; and

,

wherein the estimating of the interference is based on said information and the information on scheduling decisions associated with the radio resource R.

12. Network node according to claim 10 or 11, further comprising:

a determining unit, adapted to determine a decoding success probability for the communication of the UE in radio resource R based on the estimated interference, and

wherein the predicting unit is adapted to predict whether a retransmission of the UE communication is required based on the determined decoding success probability and the predetermined criterion.

13. Network node according to claim 12, wherein the determining of the decoding success probability comprises:

estimating a signal to interference and noise ratio, SINR, for the UE communication in radio resource R; and

mapping said SINR to a success probability using tabulated decoder performance.

14. Network node according to claim 10, wherein the predetermined criterion involves a SINR threshold value and/or a block error rate, BLER, threshold value, representing a breakpoint between decoding success and decoding failure.

15. Network node according to any of the claim 10, wherein the network node A is the BS C, operable to serve and schedule the UE.

16. Network node according to claim 15, further comprising:

a scheduler, adapted to schedule a retransmission of the UE communication when the prediction indicates that a retransmission is required.

17. Base Station, BS, B, operable in a wireless communication system comprising a user equipment, UE, being scheduled, by a BS C, for communication in a radio resource R, the communication system further comprising a network node A according to claim 10, said BS comprising:

a providing unit, adapted to provide information on scheduling decisions made by the BS B to the network node A,

thus enabling the network node A to estimate an interference to the communication of the UE in radio resource R based on said information; and

further to predict whether a retransmission of the UE communication is required, based on the estimated interference and a predetermined criterion.

18. Base Station B, according to claim 17, further adapted to provide one or more of:

an estimated path gain or channel-measurements associated with a UE served by the BS B;

an estimated path gain to neighboring cells for a UE served by the BS B;

an estimated path gain to a UE heard by the BS B;

channel-measurements to a UE heard by the BS B;

an estimated decoding success of a UE served by the BS B; and

a decoding success of transmissions received, by the BS B, from a UE.