ADAPTATION OF CONTROL SIGNALING TRANSMISSIONS TO VARIATIONS IN RESPECTIVE RESOURCES

• US 20130223366A1
• Filed: 02/26/2013
• Published: 08/29/2013
• Est. Priority Date: 02/27/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: PAPASAKELLARIOU, Aris, JI, Hyoungju
• Granted Patent: US 9,635,658 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 5/0076 Allocation utility-based
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• 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

A method and an apparatus for a User Equipment (UE) to receive a first type of a Physical Downlink Control CHannel (PDCCH) or a second type of a PDCCH in a Transmission Time Interval (TTI) are provided whereby the first type of PDCCH and the second type of PDCCH convey respective Downlink Control Information (DCI) formats containing Cyclic Redundancy Check (CRC) bits scrambled with a Radio Network Temporary Identifier (RNTI). The method includes receiving by the UE a first bitmap associated with a number of TTIs equal to the first bitmap size, wherein each element of the first bitmap indicates whether a TTI is of a first type or of a second type, decoding by the UE only PDCCH of the first type if the TTI is of the first type, and decoding by the UE only PDCCH of the second type if the TTI is of the second type.

Claims

3-1. The method of claim 1, wherein the UE receives a first type of control information only by PDCCH of the first type, and receives a second type of control information only by PDCCH of the second type.

6. The method of claim 5, wherein the first type of control information provides scheduling information for a transmission of paging, random access response, or system information, and the second type of control information provides other information for more than one UE.

8. A method for a User Equipment (UE) communicating with a base station to receive a Physical Downlink Control CHannel (PDCCH) transmitted by the base station in Resource Elements (REs) of a set of Physical Resource Blocks (PRBs), a single PRB of the set of PRBs comprising a number of frequency sub-carriers over a Transmission Time Interval (TTI), using an aggregation level of L Control Channel Elements (CCEs) in one of M^(L) candidate PDCCH locations, the method comprising:

determining by the UE whether the number of REs in a PRB available for transmitting PDCCHs is smaller than a predetermined number;

determining by the UE a first number of M^(L) candidate PDCCH locations for decoding respective PDCCHs if the number of REs in a PRB available for transmitting PDCCHs is smaller than the predetermined number; and

determining by the UE a second number of M^(L) candidate PDCCH locations for decoding respective PDCCHs if the number of REs in a PRB available for transmitting PDCCHs is larger than or equal to the predetermined number wherein the first number is different than the second number.

9. The method of claim 8, wherein the predetermined number of REs in a PRB is determined so that the transmission of a Downlink Control Information (DCI) format in a PDCCH transmitted using one CCE is with a predetermined code rate.

10. The method of claim 8, wherein for L=1, the first number of M^(L) candidate PDCCH locations is zero, and the second number of M^(L) candidate PDCCH locations is larger than zero.

11. The method of claim 10, wherein for at least one value L>

1, the first number of M^(L) candidate PDCCH locations is larger than the second number of M^(L) candidate PDCCH locations.

12. The method of claim 8, wherein the UE determines the number of REs in a PRB available for transmitting PDCCHs in the TTI from the total number of REs in a PRB after excluding at least REs used to transmit Common Reference Signals (CRS), Channel State Information Reference Signals (CSI-RS), and other control channels.

13. The method of claim 8, wherein the base station transmits PDCCH in one of two sets of PRBs configured to the UE for PDCCH transmissions through higher layer signaling.

14. The method of claim 13, wherein the number of PRBs in the first set of PRBs is larger than the number of PRBs in the second set of PRBs.

15. The method of claim 14, wherein for at least one value of L, the number of PDCCH decoding operations in the first set of PRBs is different than in the second set of PRBs.

16. The method of claim 8, wherein the number of CCEs in a PRB is two if the number of REs in a PRB available for transmitting PDCCHs is smaller than the predetermined number, and the number of CCEs in a PRB is four otherwise.

17. The method of claim 8, wherein the number of CCEs in a PRB is always four.

18. A User Equipment (UE) apparatus for receiving either a first type of a Physical Downlink Control CHannel (PDCCH) or a second type of a PDCCH transmitted by a base station in a Transmission Time Interval (TTI), the first type of PDCCH and the second type of PDCCH conveying respective Downlink Control Information (DCI) formats containing Cyclic Redundancy Check (CRC) bits scrambled with a same type of a Radio Network Temporary Identifier (RNTI), the apparatus comprising:

a receiver configured to receive a first bitmap associated with a number of TTIs equal to the first bitmap size, wherein each element of the first bitmap indicates whether a TTI is of a first type or of a second type; and

a detector configured to detect only PDCCH of the first type if the TTI is of the first type, and to detect only PDCCH of the second type if the TTI is of the second type.

19. The apparatus of claim 18, wherein the first bitmap has a same size as a second bitmap transmitted by the base station over an X2 interface with other base stations, the second bitmap being associated with a number of TTIs equal to the second bitmap size, and

wherein each element of the second bitmap indicates whether, in the respective TTI, the base station transmits signals with reduced power, nominal power or zero power.

20. The apparatus of claim 18, wherein the transmission of the PDCCH of the first type in a first TTI is over an operating bandwidth and over at most a predetermined number of TTI symbols starting from the beginning of the TTI, and the transmission of the PDCCH of the second type in a second TTI is over a subset of the operating bandwidth and over all symbols of the second TTI starting after at most the predetermined number symbols from the beginning of the TTI.

21. The apparatus of claim 18, wherein the transmission of an acknowledgement signal from the base station to the apparatus in response to a reception by the base station of data information transmitted by the apparatus is in resources in a first set of resources used to transmit PDCCH of the first type if the TTI is of the first type, and in resources in a second set of resources used to transmit PDCCH of the second type if the TTI is of the second type.

22. The apparatus of claim 18, wherein the apparatus receives a first type of control information only by PDCCH of the first type and receives a second type of control information only by PDCCH of the second type.

23. The apparatus of claim 22, wherein the first type of control information provides scheduling information for a transmission of paging, random access response, or system information, and the second type of control information provides other information for more than one UE apparatus.

24. The apparatus of claim 18, wherein the PDCCH of the first type is transmitted with a first aggregation level of Control Channel Elements (CCEs) of the first type, the PDCCH of the second type is transmitted with a second aggregation level of CCEs of the second type, and the apparatus performs a different number of decoding operations for the PDCCH of the first type than for the PDCCH of the second type, and

wherein the first aggregation level is equal to the second aggregation level.

25. A User Equipment (UE) apparatus for receiving a Physical Downlink Control CHannel (PDCCH) transmitted by a base station in Resource Elements (REs) of a set of Physical Resource Blocks (PRBs), a single PRB of the set of PRBs comprising a number of frequency sub-carriers over a Transmission Time Interval (TTI), using an aggregation level of L Control Channel Elements (CCEs) in one of M^(L) candidate PDCCH locations, the apparatus comprising:

a comparator configured to determine whether the number of REs in a PRB available for transmitting PDCCHs is smaller than a predetermined number;

a searcher configured to determine a first number of M^(L) candidate PDCCH locations if the number of REs in a PRB available for transmitting PDCCHs is smaller than the predetermined number or to determine a second number of M^(L) candidate PDCCH locations if the number of REs in a PRB available for transmitting PDCCHs is larger than or equal to the predetermined number wherein the first number is different than the second number; and

a decoder configured to decode PDCCHs in the respective candidate PDCCH locations.

26. The apparatus of claim 25, wherein the predetermined number of REs in a PRB is determined so that the transmission of a Downlink Control Information (DCI) format in a PDCCH transmitted using one CCE is with a predetermined code rate.

27. The apparatus of claim 25, wherein for L=1, the first number of M^(L) candidate PDCCH locations is zero and the second number of M^(L) candidate PDCCH locations is larger than zero.

28. The apparatus of claim 27, wherein for at least one value L>

1, the first number of M^(L) candidate PDCCH locations is larger than the second number of M^(L) candidate PDCCH locations.

29. The apparatus of claim 25, wherein the apparatus determines the number of REs in a PRB available for transmitting PDCCHs in the TTI from the total number of REs in a PRB after excluding at least REs used to transmit Common Reference Signals (CRS), Channel State Information Reference Signals (CSI-RS), and other control channels.

30. The apparatus of claim 25, wherein the base station transmits PDCCH in one of two sets of PRBs configured to the apparatus for PDCCH transmissions through higher layer signaling.

31. The apparatus of claim 30, wherein the number of PRBs in the first set of PRBs is larger than the number of PRBs in the second set of PRBs.

32. The apparatus of claim 31, wherein for at least one value of L, the number of PDCCH decoding operations in the first set of PRBs is different than in the second set of PRBs.

33. The apparatus of claim 25, wherein the number of CCEs in a PRB is two if the number of REs in a PRB available for transmitting PDCCHs is smaller than the predetermined number, and the number of CCEs in a PRB is four otherwise.

34. The apparatus of claim 25, wherein the number of CCEs in a PRB is always four.