Method and apparatus for control channel transmission and reception

• US 9,197,387 B2
• Filed: 08/08/2012
• Issued: 11/24/2015
• Est. Priority Date: 08/15/2011
• Status: Expired due to Fees

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Inventors: Nory, Ravikiran, Krishnamurthy, Sandeep H., Love, Robert T., Nangia, Vijay, Nimbalker, Ajit, Sayana, Krishna Kamal, Zhuang, Xiangyang
• Primary Examiner(s): Morlan, Robert M
• Application Number:
  US13/569,606
• Publication Number:
  US 20130044727A1
• Time in Patent Office: 1,203 Days
• US Class Current: 1/1
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• 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: H04L 5/0092 Indication of how the channel is divided

Abstract

A user equipment (UE) receives a signal comprising multiple resource blocks and configured for receiving a subframe comprising multiple time-frequency resources, the time-frequency resources comprising at least two control channel candidates. The UE determines a first control channel candidate of the at least two control channel candidates in the subframe, determines a first antenna port (AP) associated with the first control channel candidate, decodes the first control channel candidate based on the first AP, determines a second control channel candidate of the at least two control channel candidates in the subframe, determines a second AP associated with the second control channel candidate, and decodes the second control channel candidate based on the second AP, wherein the AP used for decoding the first control channel candidate is distinct from the AP used for decoding the second control channel candidate.

Claims

1. A method in a user equipment of receiving control information from a wireless network, the method comprising:

receiving a subframe comprising a plurality of time-frequency resources, the time-frequency resources comprising at least two control channel candidates;

determining a first control channel candidate in the subframe;

determining at least one first antenna port associated with the first control channel candidate;

decoding the first control channel candidate of the at least two control channel candidates based on the determined at least one first antenna port;

determining a second control channel candidate in the subframe;

determining at least one second antenna port associated with the second control channel candidate;

decoding the second control channel candidate of the at least two control channel candidates based on the determined at least one second antenna port;

and receiving control information in one of the two control channel candidates;

wherein the at least one first antenna port used for decoding the first control channel candidate is distinct from the at least one second antenna port used for decoding the second control channel candidate, and

wherein the at least one first antenna port and the at least one second antenna port are respectively determined for the first control channel candidate and the second control channel candidate as a hash function of a Resource Block (RB), or Control Channel Element (CCE) index of an RB, or a CCE contained in the candidate.

2. The method of claim 1, wherein the plurality of time-frequency resources are arranged in resource blocks and a control channel candidate is associated with one or more of the resource blocks.

3. The method of claim 1, where the step of determining at least one antenna port associated with the first control channel candidate comprises the step of determining the antenna port based on a first resource block associated with the first control channel candidate.

4. The method of claim 1, wherein the first control channel candidate comprises a first control channel element within a first resource block.

5. The method of claim 4, wherein the second control channel candidate comprises a second control channel element within a second resource block.

6. The method of claim 1, wherein the determining at least one antenna port associated with the first control channel candidate comprises determining the at least one antenna port based at least on one of the following:

a first resource block Index associated with the control channel candidate,

an associated downlink control information (DCI) format hypothesis, a System Frame Number, a Slot Number, a Cell Identifier, a Point Identifier,

a control antenna port identifier sent via a legacy control channel,

a control port hopping pattern,

restricted ports signaled via higher layer signaling, and

a channel state information reference signal (CSI-RS) configuration.

7. The method of claim 1, wherein decoding the first control channel candidate comprises:

obtaining a channel estimate associated with the reception of the first control channel candidate based on a first reference signal associated with the at least one first antenna port; and

decoding the received signal based on the control channel candidate and the obtained channel estimate to detect downlink control information.

8. The method of claim 1, wherein decoding the second control channel candidate comprises:

obtaining a channel estimate associated with the reception of the second channel candidate based on a reference signal associated with the at least one second antenna port; and

decoding the received signal based on the control channel candidate and the obtained channel estimate to detect downlink control information.

9. The method of claim 1, wherein at least one of the first antenna port and the second antenna port is determined based on a signal received from the wireless network.

10. The method of claim 1, further comprising:

estimating channel state information (CSI) associated with a set of antenna ports that includes the first antenna port and the and the second antenna port and

selecting the first antenna port and the second antenna port based on the estimated CSI.

11. A user equipment capable of receiving control information from a wireless network, the user equipment comprising;

a wireless transceiver; and

a signal processing unit coupled to the transceiver and that is configured to receive a subframe comprising a plurality of time-frequency resources, the time-frequency resources comprising at least two control channel candidates, determine a first control channel candidate of the at least two control channel candidates in the subframe, determined at least one first antenna port associated with the first control channel candidate, decode the first control channel candidate based on the determined at least one first antenna port, determine a second control channel candidate of the at least two control channel candidates in the subframe, determine at least one second antenna port associated with the second control channel candidate, decode the second control channel candidate based on the determined at least one second antenna port, and receive control information in one of the two control channel candidates, wherein at least one antenna port used for decoding the first control channel candidate is distinct from one antenna port used for decoding the second control channel candidate, and wherein the at least one first antenna port and the at least one second antenna port are respectively determined for the first control channel candidate and the second control channel candidate as a hash function of a Resource Block (RB), or Control Channel Element (CCE) index of an RB, or a CCE contained in the candidate.

12. The user equipment of claim 11, wherein the plurality of time-frequency resources are arranged in resource blocks and a control channel candidates is associated with one or more of the resource blocks.

13. The user equipment of claim 11, wherein the step of determining at least on antenna port associated with the first control channel candidate comprises the step of determining the antenna port based on a first resource block associated with the first control channel candidate.

14. The user equipment of claim 11, wherein the first control channel candidate comprises a first control channel element within a first resource block.

15. The user equipment of claim 14, wherein the second control channel candidate comprises a second control channel element within a second resource block.

16. The user equipment of claim 11, wherein the signal processing unit is configured to determine at least one antenna port associated with the first control channel candidate by determining the at least one antenna port based at least one of the following:

a first resource block Index associated with the control channel candidate,

an associated downlink control information (DCI) format hypothesis, a System Frame Number, a Slot Number, a Cell Identifier, a Point Identifier,

a control antenna port identifier sent via legacy control channel,

a control port hopping pattern,

restricted ports signaled via higher layer signaling, and

a channel state information reference signal (CSI-RS) configuration.

17. The user equipment of claim 11, wherein the signal processing unit is configured to decode the first control channel by obtaining a channel estimate associated with the reception of the first control channel candidate based on a first reference signal associated with the at least one first antenna port and decoding the received signal based on the control channel candidate and the obtained channel estimate to detect downlink control information.

18. The user equipment of claim 11, wherein the signal processing unit is configured to decode the second control channel candidate by obtaining a channel estimate associated with the reception of the second channel candidate based on a reference signal associated with the at least one second antenna port and decoding the received signal based on the control candidate and the obtained channel estimate to detect downlink control information.

19. The user equipment of claim 11, wherein at least one of the first antenna port and the second antenna port is determined based on a signal received from the wireless network.

20. The user equipment of claim 11, wherein the signal processing unit is configured to estimate channel state information (CSI) associated with a set of antenna ports that includes the first antenna port and the second antenna port and select the first antenna port and the second antenna port based on the estimated CSI.