Aggregation of resources in enhanced control channels

• US 9,942,890 B2
• Filed: 09/08/2016
• Issued: 04/10/2018
• Est. Priority Date: 03/19/2012
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Frenne, Mattias, Cheng, Jung-Fu, Furuskog, Johan, Koorapaty, Havish, Larsson, Daniel
• Primary Examiner(s): CRUTCHFIELD, CHRISTOPHER M
• Application Number:
  US15/259,494
• Publication Number:
  US 20160381667A1
• Time in Patent Office: 579 Days
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0686 Hybrid systems, i.e. switching and simultaneous transmission
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04L 1/0068 by puncturing
• CPC Class Codes: H04L 1/0069 Puncturing patterns
• CPC Class Codes: H04L 27/2627 Modulators
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

The set of resource aggregation levels available for forming an enhanced control channel message may vary from one subframe to another, based on the level of puncturing in the transmitted subframes. An example method begins with determining members of a set of aggregation levels usable to aggregate the non-overlapping subsets of resource elements for transmitting downlink control information. This determining is based on a puncturing level to be used for the transmission of the downlink control information. Downlink control information for the given subframe is mapped to one or more non-overlapping subsets of resource elements in the at least one block of time-frequency resources, according to an aggregation level selected from the determined set, and then transmitted, in the one or more non-overlapping subsets. This method may be repeated for each of several subframes, where the puncturing may differ from one subframe to another.

Claims

1. A method for receiving downlink control information in a radio communication system, characterized in that the method comprises, for a first subframe in which a plurality of non-overlapping subsets of resource elements in at least one block of time-frequency resources are to be aggregated for a received transmission of first downlink control information:

determining members of a first set of aggregation levels usable to aggregate the non-overlapping subsets of resource elements for the received transmission of the first downlink control information, wherein said determining comprises determining that one set of aggregation levels is usable when the number of resource elements available for transmission of downlink control information is above or equal to a threshold, and determining that a different set of aggregation levels is usable when the number of resource elements available for transmission of downlink control information is below the threshold, the different set comprising an aggregation level which is higher than all the aggregation levels in the one set; and

receiving the first downlink control information by de-mapping the first downlink control information from one or more first non-overlapping subsets of resource elements in the at least one block of time-frequency resources, according to an aggregation level selected from the determined first set.

2. The method of claim 1, further comprising, for a second subframe:

determining members of a second set of aggregation levels, based on a puncturing level to be used for a received transmission of second downlink control information, wherein the second set differs from the first set; and

receiving the second downlink control information by de-mapping the second downlink control information from one or more second non-overlapping subsets of resource elements in the at least one block of time-frequency resources, according to an aggregation level selected from the determined second set.

3. The method of claim 1, wherein the different set comprises an aggregation level higher than 12.

4. The method of claim 1, wherein the one set usable when the number of resource elements available for transmission of downlink control information is above or equal to a threshold comprises aggregation level 1, and the different set does not comprise aggregation level 1.

5. The method of claim 1, wherein the number of resource elements available for transmission of downlink control information to be used depends on a number of reference signals in the at least one block of time-frequency resources in the first subframe.

6. The method of claim 1, wherein the number of resource elements available for transmission of downlink control information to be used depends on a number of Orthogonal Frequency-Division Multiplexing (OFDM) symbols reserved exclusively for control information in the at least one block of time-frequency resources.

7. The method of claim 1, wherein the at least one block of time-frequency resources is a Physical Resource Block (PRB) pair in a Long-Term Evolution (LTE) network.

8. A user equipment apparatus arranged to receive downlink control information in a radio communication system, the user equipment apparatus comprising transmitter circuits and receiver circuits adapted to receive and transmit radio signals over an air interface and further comprising one or more processing circuits, wherein the processing circuits are configured to, for a first subframe in which a plurality of non-overlapping subsets of resource elements in at least one block of time-frequency resources are to be aggregated for a received transmission of first downlink control information:

determine members of a first set of aggregation levels usable to aggregate the non-overlapping subsets of resource elements for the received transmission of the first downlink control information, wherein said determining comprises determining that one set of aggregation levels is usable when the puncturing level is below a threshold, and determining that a different set of aggregation levels is usable when the puncturing level is above or equal to the threshold, the different set comprising an aggregation level that is higher than all the aggregation levels in the one set; and

receive the first downlink control information by de-mapping the first downlink control information from one or more first non-overlapping subsets of resource elements in the at least one block of time-frequency resources, according to an aggregation level selected from the determined first set.

9. The user equipment of claim 8, wherein the one or more processing circuits are further configured to, for a second subframe:

determine members of a second set of aggregation levels, based on a puncturing level to be used for a received transmission of second downlink control information, wherein the second set differs from the first set; and

receive the second downlink control information by de-mapping the second downlink control information from one or more second non-overlapping subsets of resource elements in the at least one block of time-frequency resources, according to an aggregation level selected from the determined second set.

10. The user equipment of claim 8, wherein the different set comprises an aggregation level higher than 12.

11. The user equipment of claim 8, wherein the one set usable when the number of resource elements available for transmission of downlink control information is above or equal to a threshold comprises aggregation level 1, and the different set does not comprise aggregation level 1.

12. The user equipment apparatus of claim 8, wherein the number of resource elements available for transmission of downlink control information to be used depends on a number of reference signals in the at least one block of time-frequency resources in the first subframe.

13. The user equipment apparatus of claim 8, wherein the number of resource elements available for transmission of downlink control information to be used depends on a number of Orthogonal Frequency-Division Multiplexing (OFDM) symbols reserved exclusively for control information in the at least one block of time-frequency resources.

14. The user equipment apparatus of claim 8, wherein the at least one block of time-frequency resources is a Physical Resource Block (PRB) pair in a Long-Term Evolution (LTE) network.

15. A method for receiving downlink control information in a radio communication system, the method comprising, for a first subframe in which a plurality of non-overlapping subsets of resource elements in at least one block of time-frequency resources are to be aggregated for a received transmission of first downlink control information:

determining members of a first set of aggregation levels usable to aggregate the non-overlapping subsets of resource elements for the received transmission of the first downlink control information, wherein said determining comprises determining that one set of aggregation levels is usable when the puncturing level is below a threshold, and determining that a different set of aggregation levels is usable when the puncturing level is above or equal to the threshold, the different set comprising an aggregation level that is higher than all the aggregation levels in the one set; and

receiving the first downlink control information by de-mapping the first downlink control information from one or more first non-overlapping subsets of resource elements in the at least one block of time-frequency resources, according to an aggregation level selected from the determined first set.

16. The method of claim 15, wherein the one or more processing circuits are further configured to, for a second subframe:

determine members of a second set of aggregation levels, based on a puncturing level to be used for a received transmission of second downlink control information, wherein the second set differs from the first set; and

receive the second downlink control information by de-mapping the second downlink control information from one or more second non-overlapping subsets of resource elements in the at least one block of time-frequency resources, according to an aggregation level selected from the determined second set.

17. The method of claim 15, wherein the different set comprises an aggregation level higher than 12.

18. The method of claim 15, wherein the one set usable when the number of resource elements available for transmission of downlink control information is above or equal to a threshold comprises aggregation level 1, and the different set does not comprise aggregation level 1.

19. The method of claim 15, wherein the number of resource elements available for transmission of downlink control information to be used depends on a number of reference signals in the at least one block of time-frequency resources in the first subframe.

20. The method of claim 15, wherein the number of resource elements available for transmission of downlink control information to be used depends on a number of Orthogonal Frequency-Division Multiplexing (OFDM) symbols reserved exclusively for control information in the at least one block of time-frequency resources.

21. The method of claim 15, wherein the at least one block of time-frequency resources is a Physical Resource Block (PRB) pair in a Long-Term Evolution (LTE) network.

22. A user equipment apparatus arranged to receive downlink control information in a radio communication system, the user equipment apparatus comprising transmitter circuits and receiver circuits adapted to receive and transmit radio signals over an air interface and further comprising one or more processing circuits, wherein the processing circuits are configured to, for a first subframe in which a plurality of non-overlapping subsets of resource elements in at least one block of time-frequency resources are to be aggregated for a received transmission of first downlink control information:

determine members of a first set of aggregation levels usable to aggregate the non-overlapping subsets of resource elements for the received transmission of the first downlink control information, wherein said determining comprises determining that one set of aggregation levels is usable when the number of resource elements available for transmission of downlink control information is above or equal to a threshold, and determining that a different set of aggregation levels is usable when the number of resource elements available for transmission of downlink control information is below the threshold, the different set comprising an aggregation level which is higher than all the aggregation levels in the one set, and

receive the first downlink control information by de-mapping the first downlink control information from one or more first non-overlapping subsets of resource elements in the at least one block of time-frequency resources, according to an aggregation level selected from the determined first set.

23. The user equipment apparatus of claim 22, further comprising, for a second subframe:

determining members of a second set of aggregation levels, based on a puncturing level to be used for a received transmission of second downlink control information, wherein the second set differs from the first set; and

receiving the second downlink control information by de-mapping the second downlink control information from one or more second non-overlapping subsets of resource elements in the at least one block of time-frequency resources, according to an aggregation level selected from the determined second set.

24. The user equipment apparatus of claim 22, wherein the different set comprises an aggregation level higher than 12.

25. The user equipment apparatus of claim 22, wherein the one set usable when the number of resource elements available for transmission of downlink control information is above or equal to a threshold comprises aggregation level 1, and the different set does not comprise aggregation level 1.

26. The user equipment apparatus of claim 22, wherein the number of resource elements available for transmission of downlink control information to be used depends on a number of reference signals in the at least one block of time-frequency resources in the first subframe.

27. The user equipment apparatus of claim 22, wherein the number of resource elements available for transmission of downlink control information to be used depends on a number of Orthogonal Frequency-Division Multiplexing (OFDM) symbols reserved exclusively for control information in the at least one block of time-frequency resources.

28. The user equipment apparatus of claim 22, wherein the at least one block of time-frequency resources is a Physical Resource Block (PRB) pair in a Long-Term Evolution (LTE) network.