Methods and apparatus for discovery signals for LTE advanced

• US 10,057,839 B2
• Filed: 09/29/2014
• Issued: 08/21/2018
• Est. Priority Date: 09/27/2013
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ng, Boon Loong, Novlan, Thomas, Papasakellariou, Aris, Nam, Young-Han, van Lieshout, Gerardus Johannes Petrus
• Primary Examiner(s): Mesfin, Yemane
• Assistant Examiner(s): Elmejjarmi, Abdelillah
• Application Number:
  US14/500,192
• Publication Number:
  US 20150092768A1
• Time in Patent Office: 1,422 Days
• CPC Class Codes: H04J 11/0069 Cell search, i.e. determining cell identity [cell-ID] design of multiplexing codes H04J13/00; processing access restriction or access information H04W48/16; discovery of network devices for network data management H04W8/005; sounding signals for channel estimation H04L25/0226; structure of reference signals in multicarrier modulation systems H04L27/2613; frame, time or carrier synchronisation in multicarrier modulation systems H04L27/2655
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements
• CPC Class Codes: H04L 27/2692 with preamble design, i.e. with negotiation of the synchronisation sequence with transmitter or sequence linked to the algorithm used at the receiver
• 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: H04W 48/16 Discovering, processing access restriction or access information

Abstract

A system and method for enhanced cell detection by a User Equipment (UE) is provided. The UE includes a transceiver configured to receive a discovery reference signal (DRS) occasion from at least one transmission point. The DRS occasion comprising a set of consecutive DRS sub-frames. The UE also includes processing circuitry configured to: in response to detecting a physical cell identity (PCID) of a Primary Synchronization Signal (PSS)/Secondary Synchronization Signal (SSS)/Cell-Specific Reference Signal (CRS) that is the same as a reference PCID for a configured Channel State Information-Reference Signal (CSI-RS) resource, the processing circuitry attempts to detect or measure the CSI-RS using the timing obtained from the PSS/SSS/CRS; and in response to not detecting a PCID of PSS/SSS/CRS that is the same as the reference PCID for a configured CSI-RS resource (TP), the processing circuitry does not attempt to detect or measure the CSI-RS.

Claims

1. A user equipment (UE), comprising:

a transceiver configured to receive a discovery reference signal (DRS) occasion from at least one transmission point, the DRS occasion comprising a set of consecutive DRS sub-frames including a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) within one or more of a first two of the set of consecutive DRS sub-frames for the DRS occasion; and

a processing circuitry configured to;

receive a DRS configuration information including synchronization assistance information for each transmission point, the synchronization assistance information configured by a network and comprising a physical cell identity (PCID) for transmission point identification,

assume that the PSS, the SSS, and a Cell-Specific Reference Signal (CRS) each corresponding to the PCID are quasi-co-located (QCL) with respect to average delay and Doppler shift,

perform DRS measurement according to the DRS configuration information to determine a reference signal received power (RSRP) of the at least one transmission point, and

transmit, via the transceiver, a report of the DRS measurement, and

wherein;

when the processing circuitry detects that a PCID of the PSS, the SSS, and the CRS is the same as a reference PCID for a configured Channel State Information Reference Signal (CSI-RS) resource for a transmission point (TP), the processing circuitry attempts to detect or measure the CSI-RS using timing obtained from the PSS and the SSS, and

when the processing circuitry does not detect that a PCID of the PSS, the SSS, and the CRS is the same as the reference PCID for the configured CSI-RS resource for the TP, the processing circuitry does not attempt to detect or measure the CSI-RS.

2. The UE as set forth in claim 1, wherein the set of consecutive DRS sub-frames for the DRS occasion include at least one of:

a Channel State Information Reference Signal (CSI-RS);

a Positioning Reference Signal (PRS); and

the CRS.

3. The UE as set forth in claim 1, wherein the PSS and the SSS are included in a first of the first two sub-frames.

4. The UE as set forth in claim 1, wherein the PSS is included in a second of the first two sub-frames and the SSS is included in a first of the first two sub-frames and wherein the processing circuitry is configured to assume that the sub-frame containing the PSS does not contain Channel State Information Reference Signal (CSI-RS).

5. The UE as set forth in claim 1, wherein

for FDD, a first sub-frame of a DRS occasion carries the PSS and the SSS, and

for TDD, the first sub-frame of a DRS occasion carries the SSS and a second sub-frame of a DRS occasion carries the PSS.

6. The UE as set forth in claim 1, wherein the DRS configuration information is configured to indicate at least one of:

a timing offset of a start of a Channel State Information Reference Signal (CSI-RS) sub-frame relative to a starting sub-frame of the DRS occasion;

a first sub-frame (SF n) of the DRS occasions;

a duration information, a sub-frame number (N) for the DRS occasions;

a start of the DRS occasion;

a sub-frame location of the PSS and the SSS for Frequency Division Duplexing (FDD), a sub-frame location of the SSS for Time Division Duplexing (TDD); and

information of more than one starting sub-frame of the DRS occasions.

7. The UE as set forth in claim 1, wherein the report of the DRS measurement includes one or more of:

a Physical Cell Identity (PCI), a reference PSS, a reference SSS, a PCI set indicator, a strongest PCI, information pertaining to a detected Channel State Information Reference Signal (CSI-RS) resource, a CSI-RS scrambling id, a virtual id, a CSI-RS index, and a sub-frame configuration.

8. The UE as set forth in claim 1, wherein the processing circuitry is configured to determine a set of Channel State Information Reference Signal (CSI-RS) indices to be searched from a signaling of a set of N_ID^CSI, wherein N is a scrambling identity of the CSI-RS.

9. The UE as set forth in claim 1, wherein the processing circuitry is configured to determine a set of N_ID^CSI from a signaling of a set of Channel State Information Reference Signal (CSI-RS) indices to be searched, wherein N is a scrambling identity of the CSI-RS.

10. The UE as set forth in claim 1, wherein the processing circuitry is configured to implement a timer such that timing obtained from the PSS, and the SSS can be assumed valid for a Channel State Information Reference Signal (CSI-RS) detection and measurement as long as the timer is running.

11. The UE as set forth in claim 1, wherein the DRS is a Channel State Information Reference Signal (CSI-RS) based DRS that is configured by the network as part of a CSI-RS for CSI measurement.

12. The UE as set forth in claim 1, wherein, when Channel State Information Reference Signal (CSI-RS) ports of multiple cells are transmitted in the same set of time-frequency resources, the processing circuitry is configured to receive an index ([0, 1]) of a length-2 Orthogonal Cover Code (OCC).

13. The UE as set forth in claim 12, wherein, when the OCC index is not signaled, the processing circuitry is configured to blindly detect an index for an OCC applied to a CSI-RS.

14. The UE as set forth in claim 12, wherein the processing circuitry is configured to recognize a cell with a single CSI-RS port that is spread with an OCC [1 1] over consecutive symbols and when the CSI-RS ports of multiple cells cannot be transmitted in the same set of time-frequency resources, the processing circuitry is configured to assume that no OCC is applied or assumes a fixed OCC is applied.

15. The UE as set forth in claim 1, wherein a transmission point id (TPID) is derived from one or more of:

the PCID, a Channel State Information Reference Signal (CSI-RS) index, a CSI-RS Resource Element configuration, CSI-RS sub-frame configuration information, and a CSI-RS virtual cell identifier.

16. A user equipment (UE), comprising:

a transceiver configured to receive a discovery reference signal (DRS) occasion from at least one transmission point, the DRS occasion comprising a set of consecutive DRS sub-frames including a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) within one or more of a first two of the set of consecutive DRS sub-frames for the DRS occasion, wherein

for Frequency Division Duplexing (FDD), a first sub-frame of the set of consecutive DRS sub-frames for the DRS occasion carries PSS and SSS, and

for Time Division Duplexing (TDD), the first sub-frame of a DRS occasion carries the SSS and a second sub-frame of a DRS occasion carries the PSS; and

a processing circuitry configured to;

assume that the PSS, the SSS, and a Cell-Specific Reference Signal (CRS) each corresponding to a single physical cell identity (PCID) are quasi-co-located (QCL) with respect to average delay and Doppler shift,

perform DRS measurement according to DRS configuration information to determine a reference signal received power (RSRP) of the at least one transmission point, and

transmit, via the transceiver, a report of the DRS measurement, and

wherein;

when the processing circuitry detects that a PCID of the PSS, the SSS, and the CRS is the same as a reference PCID for a configured Channel State Information Reference Signal (CSI-RS) resource for a transmission point (TP), the processing circuitry attempts to detect or measure the CSI-RS using timing obtained from the PSS and the SSS, and

when the processing circuitry does not detect that a PCID of the PSS, the SSS, and the CRS is the same as the reference PCID for the configured CSI-RS resource for the TP, the processing circuitry does not attempt to detect or measure the CSI-RS.