Device, Network, and Method for Utilizing a Downlink Discovery Reference Signal

• US 20170078955A1
• Filed: 11/22/2016
• Published: 03/16/2017
• Est. Priority Date: 04/04/2013
• Status: Active Grant

• Current Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Cheng, Qian, Xiao, Weimin, Liu, Jialing
• Granted Patent: US 10,924,984 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 5/00 Arrangements affording multiple use of the transmission path
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04L 5/1469 using time-sharing
• CPC Class Codes: H04W 36/0072 of resource information of target access point
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

User equipments can achieve quick channel synchronization when establishing a connection to base stations transitioning from a sleep mode to an active mode by using discovery resource signal (DRS) processing results and cell reference signal (CRS) processing results to establish channel synchronization with a CRS antenna port. More specifically, the user equipment may be notified that the CRS antenna port and DRS antenna port are quasi-co-located (QCL), and then use DRS processing results in conjunction with CRS processing results to obtain faster channel synchronization with a CRS antenna port. This may be particularly beneficial when the target BS is transitioned from a sleep mode to an active mode in order to accept a handover of the user equipment.

Claims

1. A method for communicating in a wireless network, the method comprising:

receiving, by a user equipment (UE), a discovery signal associated with a cell, wherein the discovery signal is different than a cell-specific reference signal (CRS) associated with the cell, and wherein the discovery signal is received at a different time than the CRS; and

performing, by the UE, a discovery-signal-based radio resource management (RRM) measurement based on the discovery signal, wherein the UE does not assume other signals or physical channels are present when performing the RRM measurement.

2. The method of claim 1, wherein the discovery signal is configured via radio resource control (RRC) signaling, and wherein the CRS is not configured via RRC signaling.

3. The method of claim 1, wherein at least one signal or physical channel, other than the discovery signal, is present when the UE performs the RRM measurement.

4. The method of claim 3, wherein the at least one signal or physical channel includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical downlink shared channel (PDSCH), a physical downlink control channel (PDCCH), an enhanced physical downlink control channel (EPDCCH), a demodulation reference signal (DMRS), or a channel state information reference signal (CSI-RS) associated with the cell.

5. The method of claim 3, wherein the UE does not detect the at least one signal or physical channel.

6. The method of claim 3, wherein the UE detects the at least one signal or physical channel.

7. The method of claim 1, wherein the UE does not assume that a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical downlink shared channel (PDSCH), a physical downlink control channel (PDCCH), an enhanced physical downlink control channel (EPDCCH), a demodulation reference signal (DMRS), or a channel state information reference signal (CSI-RS) associated with the cell are transmitted in one or more downlink subframes following the subframe carrying the discovery signal when performing the discovery-signal-based RRM measurement.

8. The method of claim 7, wherein the UE assumes that the PSS, the SSS, the CRS, the PDSCH, the PDCCH, the EPDCCH, the DMRS, or the CSI-RS associated with the cell are not transmitted in the one or more downlink subframes following the subframe carrying the discovery signal when a downlink transmission of the cell is turned off.

9. The method of claim 1, wherein a first antenna port associated with the discovery signal is quasi-co-located (QCL) with a second antenna port associated with the CRS.

10. The method of claim 9, wherein the first antenna port is QCL with the second antenna port with respect to at least the average delay and Doppler shift.

11. The method of claim 1, wherein the CRS is present in every subframe when the cell is turned on, and the discovery signal is present in fewer than all subframes when the cell is turned off.

12. The method of claim 11, wherein UE performs the RRM measurement based on the discovery signal without assuming that other signals or physical channels are present in a subframe carrying the discovery signal when the cell is turned off.

13. A user equipment (UE) comprising:

a processor; and

a non-transitory computer readable storage medium coupled to the processor and storing programming for execution by the processor, the programming including instructions to;

receive a discovery signal associated with a cell, wherein the discovery signal is different than a cell-specific reference signal (CRS) associated with the cell, and wherein the discovery signal is received at a different time than the CRS; and

perform a discovery-signal-based radio resource management (RRM) measurement based on the discovery signal, wherein the UE does not assume other signals or physical channels are present when performing the RRM measurement.

14. A method for communicating in a wireless network, the method comprising:

receiving, by a user equipment (UE), a discovery signal associated with a cell, wherein the discovery signal is different than a cell-specific reference signal (CRS) associated with the cell, and wherein the discovery signal is received at a different time than the CRS; and

performing, by the UE, a discovery-signal-based radio resource management (RRM) measurement based on the discovery signal, wherein the UE assumes that other signals or physical channels are not present when performing the RRM measurement.

15. The method of claim 14, wherein the discovery signal is configured via radio resource control (RRC) signaling, and wherein the CRS is not configured via RRC signaling.

16. The method of claim 14, wherein at least one signal or physical channel, other than the discovery signal, is present when the UE performs the RRM measurement.

17. The method of claim 16, wherein the at least one signal or physical channel includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical downlink shared channel (PDSCH), a physical downlink control channel (PDCCH), an enhanced physical downlink control channel (EPDCCH), a demodulation reference signal (DMRS), or a channel state information reference signal (CSI-RS) associated with the cell.

18. The method of claim 14, wherein a first antenna port associated with the discovery signal is quasi-co-located (QCL) with a second antenna port associated with the CRS.

19. The method of claim 18, wherein the first antenna port is QCL with the second antenna port with respect to at least the average delay and Doppler shift.

20. The method of claim 14, wherein the CRS is present in every subframe when the cell is turned on, and the discovery signal is present in fewer than all subframes when the cell is turned off.