Method, system and apparatus for downlink shared channel reception in cooperative multipoint transmissions

Patent metadata

Field	Value
Publication number	US-9867174-B2
Application number	US-201414459034-A
Country	US
Kind code	B2
Filing date	Aug 13, 2014
Priority date	Jan 7, 2011
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

A method and apparatus may be used to enable reception of a downlink (DL) shared channel in a cooperative multipoint transmission (CoMP). The method and apparatus may determine whether CoMP is applied to a transmission. The method and apparatus may acquire other CoMP related information. The method and apparatus may apply to non-transparent CoMP scenarios.

First claim

What is claimed is:

1. A method implemented in a wireless transmit/receive unit (WTRU) in communication with a plurality of transmission (Tx) points, comprising:
receiving radio resource control (RRC) signaling including first and second parameters of a demodulation reference signals (DM-RS) configuration associated with the plurality of Tx points;
receiving, on a downlink control channel associated with a forthcoming coordinated downlink transmission to the WTRU, downlink control information including a scrambling identity;
on condition that the scrambling identity is a first value, generating a first DM-RS sequence for receiving DM-RS of the coordinated downlink transmission using the first parameter and the first value of the scrambling identity as inputs for initializing the first DM-RS sequence; and
on condition that the scrambling identity is a second value, generating a second DM-RS sequence for receiving DM-RS of the coordinated downlink transmission using the second parameter and the second value of the scrambling identity as inputs for initializing the second DM-RS sequence.

2. The method of claim 1 , further comprising:
provisioning the first and second parameters into the WTRU.

3. The method of claim 1 , further comprising:
receiving the coordinated downlink transmission based, at least in part, on the first DM-RS sequence or the second DM-RS sequence.

4. The method of claim 3 , wherein receiving the coordinated downlink transmission comprises:
receiving the DM-RS of the coordinated downlink transmission based, at least in part, on the first DM-RS sequence.

5. The method of claim 3 , wherein receiving the coordinated downlink transmission comprises:
receiving the DM-RS of the coordinated downlink transmission based, at least in part, on the second DM-RS sequence.

6. The method of claim 1 , wherein each of the first and second parameters comprises: any of an index of antenna ports specific to the WTRU, a value specific to the WTRU for an initialization sequence for reference-signal generation, a transmission mode specific to the WTRU, an identifier specific to the WTRU for use with initializing a reference-signal sequence, and a value based on the DM-RS configuration associated with the plurality of Tx points.

7. The method of claim 1 , wherein each of the first and second values of the scrambling identity comprises: a value of any of a scrambling identity configured using layers above a physical layer, an identity of the WTRU, a radio network temporary identifier (RNTI) of the WTRU, an identity of a transmission point, an identity of a cell of a transmission Tx point, a carrier indicator field (CIF), and a scrambling identity of one or more antenna ports.

8. The method of claim 1 , wherein the downlink control information comprises any of: (i) at least one bit for explicitly signaling to the WTRU that the coordinated downlink transmission to the WTRU is forthcoming; (ii) at least one bit implicitly signaling to the WTRU that the coordinated downlink transmission to the WTRU is forthcoming; and (iii) any of an explicit and implicit signal obtained by way of blind detection of the downlink control channel.

9. The method of claim 1 , wherein initializing any of the first and second DM-RS sequences is based on initiator, c init =(└n s /2┘+1)·(2X ID +1)·2 16 +Y ID , and wherein:
for the first DM-RS sequence, X ID is the first parameter, n s is a slot number, and Y ID is the first value of the scrambling identity; and
for the second DM-RS sequence, X ID is the second parameter, n s is a slot number, and Y ID is the second value of the scrambling identity.

10. A wireless transmit/receive unit (WTRU) comprising:
a receiver configured to:
receive radio resource control (RRC) signaling including first and second parameters of a demodulation reference signals (DM-RS) configuration associated with a plurality of transmission (Tx) points; and
receive, on a downlink control channel associated with a forthcoming coordinated downlink transmission, downlink control information including a scrambling identity; and

a processor configured to:
on condition that the scrambling identity is a first value, generate a first DM-RS sequence for receiving DM-RS of the coordinated downlink transmission using the first parameter and the first value of the scrambling identity as inputs for initializing the first DM-RS sequence; and
on condition that the scrambling identity is a second value, generate a second DM-RS sequence for receiving DM-RS of the coordinated downlink transmission using the second parameter and the second value of the scrambling identity as inputs for initializing the second DM-RS sequence.

11. The WTRU of claim 10 , wherein the WTRU comprises a memory, and wherein the processor is further configured to provision the first and second parameters into the memory.

12. The WTRU of claim 10 , wherein the receiver is configured to:
receive the coordinated downlink transmission based, at least in part, on the first DM-RS sequence or the second DM-RS sequence.

13. The WTRU of claim 10 , wherein the receiver is configured to receive the DM-RS of the coordinated downlink transmission based, at least in part, on the first DM-RS sequence or the second DM-RS sequence.

14. The WTRU of claim 10 , wherein each of the first and second parameters comprises: any of an index of antenna ports specific to the WTRU, a value specific to the WTRU for an initialization sequence for reference-signal generation, a transmission mode specific to the WTRU, an identifier specific to the WTRU for use with initializing a reference-signal sequence, and a value based on the DM-RS configuration associated with the plurality of Tx points.

15. The WTRU of claim 10 , wherein each of the first and second values of the scrambling identity comprises: a value of any of a scrambling identity configured using layers above a physical layer, an identity of the WTRU, a radio network temporary identifier (RNTI) of the WTRU, an identity of a transmission point, an identity of a cell of a transmission Tx point, a carrier indicator field (CIF), and a scrambling identity of one or more antenna ports.

16. The WTRU of claim 10 , wherein the downlink control information comprises any of: (i) at least one bit for explicitly signaling to the WTRU that the coordinated downlink transmission to the WTRU is forthcoming; (ii) at least one bit implicitly signaling to the WTRU that the coordinated downlink transmission to the WTRU is forthcoming; and (iii) any of an explicit and implicit signal obtained by way of blind detection of the downlink control channel.

17. The WTRU of claim 10 , wherein initializing any of the first and second DM-RS sequences is based on initiator, (2X ID +1)·2 16 +Y ID , and wherein:
for the first DM-RS sequence, X ID is the first parameter, n s is a slot number, and Y ID is the first value of the scrambling identity; and
for the second DM-RS sequence, X ID is the second parameter, n s is a slot number, and Y ID is the second value of the scrambling identity.

18. The WTRU of claim 10 , wherein the downlink control channel comprises any of a physical downlink control channel (PDCCH) and an enhanced PDCCH (ePDCCH).

19. The WTRU of claim 10 , wherein the coordinated downlink transmission comprises a physical downlink shared channel (PDSCH).

20. The WTRU of claim 10 , wherein:
the receiver is configured to receive the DM-RS of the coordinated downlink transmission; and
the processor is configured to perform channel estimati

Assignees

• Interdigital Patent Holdings Inc

Inventors

• Zhang Guodong
• Pelletier Ghyslain
• Haghighat Afshin
• Marinier Paul
• Cave Christopher
• Adjakple Pascal M
• Tsai Allan Y

Classifications

• H04W72/23 Primary

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04W72/042 Primary

  Electricity · mapped topic

• H04W68/005

  Transmission of information for alerting of incoming communication · CPC title

• H04B7/024 Primary

  Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems · CPC title

• H04L5/0035

  Resource allocation in a cooperative multipoint environment · CPC title