Aggregation of resources in enhanced control channels

• US 9,467,995 B2
• Filed: 09/03/2015
• Issued: 10/11/2016
• 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:
  US14/844,378
• Publication Number:
  US 20150382329A1
• Time in Patent Office: 404 Days
• Field of Search: None
• US Class Current: 1/1
• 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 transmitting downlink control information in a Long-Term Evolution (LTE) 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 transmitting the downlink control information:

determining members of a first set of aggregation levels usable to aggregate the non-overlapping subsets of resource elements for transmitting first downlink control information, wherein said determining is based on a number of reference signal symbols to be transmitted in the at least one block of time-frequency resources in the first subframe;

mapping the first downlink control information to 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; and

transmitting the first downlink control information in the one or more first non-overlapping subsets.

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

determining members of a second set of aggregation levels, based on a number of reference signal symbols to be transmitted in the at least one block of time-frequency resources in the second subframe, wherein the second set differs from the first set;

mapping the second downlink control information to 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; and

transmitting the second downlink control information in the one or more second non-overlapping subsets.

3. The method of claim 1, wherein determining the members of the first set of aggregation levels depends further 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.

4. The method of claim 1, wherein the at least one block of time-frequency resources is a Physical Resource Block (PRB) pair.

5. The method of claim 1, wherein a non-overlapping subset of resources defines an enhanced CCE (eCCE).

6. A method for receiving downlink control information in a Long-Term Evolution (LTE) 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 is based on a number of reference signal symbols to be transmitted in the at least one block of time-frequency resources in the first subframe; 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.

7. The method of claim 6, further comprising, for a second subframe:

determining members of a second set of aggregation levels, based on a number of reference signal symbols to be transmitted in the at least one block of time-frequency resources in the second subframe; 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.

8. The method of claim 6, wherein determining the members of the first set of aggregation levels depends further 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.

9. The method of claim 6, wherein the at least one block of time-frequency resources is a Physical Resource Block (PRB) pair.

10. A base station apparatus arranged to transmit downlink control information in a radio communication system, the base station apparatus comprising:

transmitter circuits and receiver circuits configured to receive and transmit radio signals over an air interface; and

one or more processing circuits 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 transmitting the downlink control information;

determine members of a first set of aggregation levels usable to aggregate the non-overlapping subsets of resource elements for transmitting first downlink control information, wherein said determining is based on a number of reference signal symbols to be transmitted in the at least one block of time-frequency resources in the first subframe;

map the first downlink control information to 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; and

transmit the first downlink control information in the one or more first non-overlapping subsets.

11. The base station apparatus of claim 10, 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 number of reference signal symbols to be transmitted in the at least one block of time-frequency resources in the second subframe, wherein the second set differs from the first set;

map the second downlink control information to 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; and

transmit the second downlink control information in the one or more second non-overlapping subsets.

12. The base station apparatus of claim 10, wherein the one or more processing circuits are configured to determine the members of the first set of aggregation levels based further 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.

13. The base station apparatus of claim 10, wherein the at least one block of time-frequency resources is a Physical Resource Block (PRB) pair.

14. The base station apparatus of claim 10, wherein a non-overlapping subset of resources defines an enhanced CCE (eCCE).

15. A user equipment apparatus configured to receive downlink control information in a Long-Term Evolution (LTE) radio communication system, the user apparatus comprising

transmitter circuits and receiver circuits configured to receive and transmit radio signals over an air interface, and

one or more processing circuits 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 is based on a number of reference signal symbols to be transmitted in the at least one block of time-frequency resources in the first subframe; 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.

16. The user equipment apparatus 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 number of reference signal symbols to be transmitted in the at least one block of time-frequency resources in the second subframe; 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 user equipment apparatus of claim 15, wherein the one or more processing circuits are configured to determine the members of the first set of aggregation levels based further 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.

18. The user equipment apparatus of claim 15, wherein the at least one block of time-frequency resources is a Physical Resource Block (PRB) pair.