SYSTEMS AND/OR METHODS FOR PROVIDING EPDCCH IN A MULTIPLE CARRIER BASED AND/OR QUASI-COLLATED NETWORK

• US 20130194931A1
• Filed: 01/27/2013
• Published: 08/01/2013
• Est. Priority Date: 01/27/2012
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Inventors: Lee, Moon-il, Koo, Changsoo, Shin, Sung-Hyuk, Stern-Berkowitz, Janet A., Rudolf, Marian, Xi, Fengjun, Marinier, Paul, Kini, Ananth, Hosseinian, Seyed Mohsen
• Granted Patent: US 9,794,913 B2
• Time in Patent Office: Days
• US Class Current: 370/241
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 72/04 Wireless resource allocation

Abstract

ePDCCH may be provided. For example, a WTRU may receive a configuration for monitoring an ePDCCH resource. Based on the configuration, the WTRU may be configured to monitor and may monitor the ePDCCH resource on a particular subframe. Additionally, a WTRU may derive an aggregation level for a subframe associated with an aggregation level number N_AL. The WTRU may transmit or monitor an ePDCCH using the aggregation level associated with the N_AL for the subframe. A WTRU may also receive a reference signal. The WTRU may then determine the type of reference signal received. The WTRU may perform a demodulation of the PDSCH or ePDCCH using a demodulation timing based on the determined type. The ePDCCH or PDSCH may also be monitored or received by identifying a demodulation reference timing implicitly based on a location of one or more ePDCCH resources where the WTRU may receive DCI.

Claims

1. A method for providing enhanced physical downlink control channel (ePDCCH) in a multiple carrier communication system, the method comprising:

receiving, at a wireless transmit and receive unit (WTRU), a configuration for monitoring an ePDCCH resource;

configuring the WTRU to monitor the ePDCCH resource on a subframe based on the configuration; and

monitoring, at the WTRU, the ePDCCH resource on the subframe.

2. The method of claim 1, wherein, for at least one of time-division duplex (TDD) or normal downlink cyclic prefix (CP), the subframe is not a special subframe associated with a particular special subframe configuration.

3. The method of claim 2, wherein the particular special subframe configuration comprises at least one of:

a special subframe configuration 0 or a special configuration 5.

4. The method of claim 1, wherein the configuration is received via higher layer signalling.

5. The method of claim 4, wherein the configuration further comprises one or more physical resource block (PRB) sets to monitor on the ePDCCH resource.

6. The method of claim 5, wherein the one or more physical resource block (PRB) sets comprise a set of enhanced control channel elements (eCCEs).

7. The method of claim 6, wherein each of the eCCEs comprises enhanced resource element groups (eREGs).

8. The method of claim 7, wherein the number of eREGs per CCE is based on a cyclic prefix (CP) and the subframe.

9. The method of claim 8, wherein the number of eREGs comprises four when the CP comprises a normal CP and the subframe comprises a normal subframe or a special subframe associated with a special subframe configuration of 3, 4, and 8.

10. The method of claim 8, wherein the number of eREGs comprises eight when the CP comprises a normal CP and the subframe comprises a special subframe associated with a special subframe configuration of 1, 2, 6, 7, and 9 or when the CP comprises an extended CP and the subframe comprises a special subframe associated with a special subframe configuration of 1, 2, 3, 5, and 6.

11. The method of claim 6, wherein the set of eCCEs may be numbered from 0 to N_ECCE,p,k−

1 where N_ECCE,p,k is the number of eCCEs in a particular PRB set p of the one or more PRBs sets associated with the subframe denoted by k.

12. The method of claim 4, wherein the ePDCCH resource monitored on the subframe based on the configuration signalled by the higher layers comprises a UE-specific search space.

13. The method of claim 12, further comprising monitoring, at the WTRU, a PDCCH resource on a subframe not configured for monitoring the ePDCCH resource based on the configuration.

14. The method of claim 13, wherein the PDCCH resource monitored comprises a common search space.

15. The method of claim 1, further comprising demodulating the ePDCCH resource using an antenna port for a channel estimation, wherein a DM-RS scrambling sequence for the antenna ports is configured to be initialized by c_init=(└

n_s/2┘

+1). (2n_ID^EPDCCH+1)·

2¹⁶+n_SCID^EPDCCH, wherein n_ID^EPDCCH is configured by UE-specific higher layer signalling.

16. The method of claim 1, wherein candidates for the ePDCCH resource of the subframe is selected based on a hashing function, wherein the hashing function is different for each ePDCCH resource.

17. A wireless transmit and receive unit (WTRU) configured to:

derive an aggregation level associated with one or more enhanced control channel elements (eCCEs) for a subframe associated with an aggregation level number N_AL for the subframe, wherein N_AL is a positive integer; and

transmit an ePDCCH using the aggregation level associated with the N_AL for the subframe.

18. The WTRU of claim 17, wherein the aggregation level for the subframe is different than an aggregation level for another subframe.

19. The WTRU of claim 17, wherein the aggregation level is derived as N_AL·

{1, 2, 4, 8}.

20. The WTRU of claim 17, wherein N_AL equals two and the aggregation level comprises {2, 4, 8, 16}.

21. The WTRU of claim 17, wherein N_AL equals one and the aggregation level comprises {1, 2, 4, 8}.

22. The WTRU of claim 17, wherein the aggregation level for the subframe is different than an aggregation level for another subframe.

23. The WTRU of claim 17, wherein the number of eCCEs available to the EPDCCH is from 0 to N_ECCE−

1 lwhere N_ECCE depends on one or more of the following;

the type of ePDCCH, the subframe, a subframe configuration, a number of resource elements (REs) in a physical resource block (PRB) associated with the ePDCCH, or a cyclic prefix (CP).

24. The WTRU of claim 17, wherein N_AL is signalled to the WTRU via at least one of:

higher layer signalling or one or more downlink control information (DCI) bits.

25. A method for receiving or monitoring an enhanced physical downlink control channel (ePDCCH) or a physical downlink shared channel (PDSCH), the method comprising:

receiving, at a wireless transmit and receive unit (WTRU), a reference symbol;

determining, at the WTRU, a type associated with the reference signal; and

performing, via the WTRU, a PDSCH demodulation when the reference signal is a channel state information reference signal (CSI-RS) using a demodulation reference timing based on a Fast Fourier Transform (FFT) timing and a channel estimation coefficient associated with the CSI-RS.

26. The method of claim 25, wherein the PDSCH and a UE-specific demodulation reference signal (RS) associated with the CSI-RS may be transmitted from the same quasi-collocated antenna ports.

27. A method for receiving or monitoring an enhanced physical downlink control channel (ePDCCH) or a physical downlink shared channel (PDSCH), the method comprising:

identifying a demodulation reference timing implicitly based on a location of one or more ePDCCH resources where a wireless transmit and receive unit (WTRU) receives downlink control information (DCI); and

performing demodulation of the ePDCCH or the PDSCH based on the demodulation reference timing.

28. The method of claim 27, wherein identifying a demodulation reference timing implicitly based on a location of one or more ePDCCH resources where a wireless transmit and receive unit (WTRU) receives downlink control information (DCI) comprises splitting a UE-specific search space into at least two subsets, wherein each subset is tied to a specific demodulation timing reference for demodulation.

29. The method of claim 28, wherein splitting the UE-specific search space into at least two subsets comprises splitting a total number of blind decoding attempts into a first subset and a second subset, wherein each of the first and second subsets is tied to a different demodulation timing reference, and wherein the different demodulation timing references may be associated with different channel state information reference signals (CSI-RSs).