SYSTEMS AND METHODS FOR AN ENHANCED CONTROL CHANNEL

• US 20130039284A1
• Filed: 02/10/2012
• Published: 02/14/2013
• Est. Priority Date: 02/11/2011
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Inventors: Marinier, Paul, Haghighat, Afshin, Nayeb Nazar, Shahrokh, Zhang, Guodong, Rudolf, Marian, Lee, Moon-il
• Granted Patent: US 10,505,680 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0092 Indication of how the channel is divided
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated

Abstract

Methods and systems for sending and receiving an enhanced downlink control channel are disclosed. The method may include receiving control channel information via an enhanced control channel. The method may also include using the control channel information to receive a shared channel. The method may include detecting the presence of the enhanced control channel in a given subframe. The enhanced control channel may be transmitted over multiple antenna ports. For example, code divisional multiplexing and de-multiplexing and the use of common and UE-specific reference signals may be utilized. New control channel elements may be defined, and enhanced control channel state information (CSI) feedback may be utilized. The presence or absence of legacy control channels may affect the demodulation and or decoding methods. The method may be implemented at a WTRU.

Claims

1. A method for a wireless transmit/receive unit (WTRU) to receive an enhanced physical downlink control channel (E-PDCCH), the method comprising:

determining whether to attempt to decode the E-PDCCH in an identified subframe on an identified component carrier;

determining a plurality of resource elements (REs) in the identified subframe on the identified component carrier that are associated with an E-PDCCH region of the identified subframe;

determining at least one E-PDCCH candidate in the E-PDCCH region of the identified component carrier, wherein the at least one E-PDCCH candidate comprises a subset of the plurality of REs in the E-PDCCH region; and

attempting to process the E-PDCCH candidate.

2. The method as in claim 1, wherein attempting to process the E-PDCCH candidate further comprises performing layer demapping by determining at least one antenna port from which the WTRU attempts to decode the E-PDCCH candidate.

3. The method as in claim 2, wherein the layer demapping is performed based on at least one received user equipment (UE)-specific reference signal.

4. The method as in claim 1, wherein determining the at least one E-PDCCH candidate in the E-PDCCH region is based on a location of at least one enhanced control channel element (E-CCE) in the E-PDCCH region.

5. The method as in claim 1, wherein attempting to process the E-PDCCH candidate further comprises demodulating a plurality of modulation symbols from the E-PDCCH candidate based on an assumed power ratio between the E-PDCCH and at least one received user equipment (UE)-specific reference signal for an antenna port that corresponds to the E-PDCCH candidate.

6. The method as in claim 1, wherein determining the at least one E-PDCCH candidate in the E-PDCCH region of the identified component carrier is based on an E-PDCCH parameter, wherein the E-PDCCH parameter comprises a determined transmission characteristic of the E-PDCCH.

7. The method as in claim 6, wherein the E-PDCCH parameter comprises at least one of an identity of at least one antenna port over which the E-PDCCH is received, a characteristic of the at least one antenna port over which the E-PDCCH is received, or a total number of antenna ports over which the E-PDCCH is received.

8. A wireless transmit/receive unit (WTRU) comprising a processor configured to:

determine whether to attempt to decode receive an enhanced physical downlink control channel (E-PDCCH) in an identified subframe on an identified component carrier;

determine a plurality of resource elements (REs) in the identified subframe on the identified component carrier that are associated with an E-PDCCH region of the identified subframe;

determine at least one E-PDCCH candidate in the E-PDCCH region of the identified component carrier, wherein the at least one E-PDCCH candidate comprises as subset of the plurality of REs in the E-PDCCH region; and

attempt to process the E-PDCCH candidate.

9. The WTRU as in claim 8, wherein the E-PDCCH candidate comprises a plurality of enhanced control channel elements (E-CCEs).

10. The WTRU as in claim 9, wherein the WTRU operates in a frequency-diverse mode and the plurality of E-CCEs are are not each contiguous in either the time domain or the frequency domain.

11. The WTRU as in claim 9, wherein the plurality of E-CCEs are received over multiple antenna ports.

12. The WTRU as in claim 8, wherein the processor is configured to attempt to process the E-PDCCH candidate based on information received in a supporting physical downlink control channel (PDCCH).

13. The WTRU as in claim 8, wherein the processor is configured receive a physical downlink shared channel (PDSCH) based on information from the E-PDCCH.

14. The WTRU as in claim 8, wherein the processor is configured to implicitly determine a transmission characteristic of a physical downlink shared channel (PDSCH) based on a transmission characteristic of the E-PDCCH.

15. A method for a wireless transmit/receive unit (WTRU) to receive an enhanced physical downlink control channel (E-PDCCH), the method comprising:

determining at least one antenna port associated with an E-PDCCH region;

determining an E-PDCCH candidate located in the E-PDCCH region based on the at least one antenna port; and

attempting to process the E-PDCCH candidate based on at least one received precoded reference signal associated with the at least one antenna port.

16. The method as in claim 15, wherein the at least one received precoded reference signal is precoded with the same precoding weights as those used for the E-PDCCH candidate.

17. The method as in claim 15, wherein the E-PDCCH is associated with multiple antenna ports and attempting to process the E-PDCCH candidate is based on a precoding relationship between the multiple antenna ports.

18. The method as in claim 15, wherein the E-PDCCH region is located outside of a legacy control region for a legacy physical downlink control channel (PDCCH).

19. The method as in claim 15, wherein the E-PDCCH is associated with multiple antenna ports and attempting to process the E-PDCCH comprises using a first precoded reference signal associated with a first antenna port to process a first portion of the E-PDCCH candidate and a second precoded reference signal associated with a second antenna port to process a second portion of the E-PDCCH candidate.

20. The method as in claim 19, wherein the first precoded reference symbol is associated with a first subset of resource elements (REs) in the E-PDCCH region and the second precoded reference symbol is associated with a second subset of REs in the PDCCH region.