Reference signals for radio link monitoring

• US 10,686,573 B2
• Filed: 09/11/2018
• Issued: 06/16/2020
• Est. Priority Date: 09/11/2017
• Status: Active Grant

• Current Assignee: Lenovo Singapore Pte Limited (Lenovo Group Ltd.)
• Original Assignee: Lenovo Singapore Pte Limited (Lenovo Group Ltd.)
• Inventors: Jung, Hyejung, Nangia, Vijay, Basu Mallick, Prateek, MolavianJazi, Ebrahim, Kuchibhotla, Ravi, Loehr, Joachim
• Primary Examiner(s): Divito, Walter J
• Application Number:
  US16/128,438
• Publication Number:
  US 20190081753A1
• Time in Patent Office: 644 Days
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0628 Diversity capabilities
• CPC Class Codes: H04B 7/063 Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04B 7/06966 using beam correspondence; using channel reciprocity, e.g. downlink beam training based on uplink sounding reference signal [SRS]
• CPC Class Codes: H04B 7/0874 using subgroups of receive antennas
• CPC Class Codes: H04B 7/088 using beam selection
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0091 Signaling for the administration of the divided path
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/365 Power headroom reporting
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams
• CPC Class Codes: H04W 8/22 Processing or transfer of terminal data, e.g. status or physical capabilities
• CPC Class Codes: Y02D 30/00 : Reducing energy consumption in communication networks

Abstract

Apparatuses, methods, and systems are disclosed for reference signals for radio link monitoring. The method includes measuring a first set of reference signals for radio link monitoring. The method includes receiving an indication of a second set of reference signals for radio link monitoring. The method includes resetting a counter in response to reception of the indication of the second set of reference signals. The first set of reference signals is associated with a first set of downlink antenna ports, the second set of reference signals is associated with a second set of downlink antenna ports, and the first set of downlink antenna ports is different from the second set of downlink antenna ports.

Claims

1. A method comprising:

measuring a first set of reference signals for radio link monitoring;

receiving an indication of at least one physical uplink control channel resource and at least one physical random access channel resource for transmitting a beam failure recovery request, wherein each of the at least one physical uplink control channel resource and the at least one physical random access channel resource are associated with at least one downlink antenna port;

determining an association between the at least one physical uplink control channel resource, the at least one physical random access channel resource, and the at least one downlink antenna port based on the indication of the at least one physical uplink control channel resource and the at least one physical random access channel resource for transmitting the beam failure recovery request;

receiving an indication of a second set of reference signals for radio link monitoring; and

resetting a counter in response to reception of the indication of the second set of reference signals;

wherein the first set of reference signals is associated with a first set of downlink antenna ports, the second set of reference signals is associated with a second set of downlink antenna ports, and the first set of downlink antenna ports is different from the second set of downlink antenna ports.

2. The method of claim 1, further comprising:

generating a first in-sync indication or an out-of-sync indication based on measuring the first set of reference signals;

generating a second in-sync indication in response to reception of the indication of the second set of reference signals if a value of the counter is not zero;

incrementing the counter in response to generation of the out-of-sync indication; and

resetting the counter in response to the first in-sync indication being generated or in response to the second in-sync indication being generated.

3. The method of claim 1, further comprising:

initiating a radio link failure timer based on a result from measuring the first set of reference signals, wherein a radio link failure is identified in response to expiration of the radio link failure timer; and

stopping the radio link failure timer in response to reception of the indication of the second set of reference signals.

4. The method of claim 1, wherein the first and second sets of reference signals comprise a non-zero transmit power channel state information-reference signal, a synchronization signal and physical broadcast channel block, or some combination thereof.

5. The method of claim 1, wherein the first set of reference signals is associated with a first set of serving physical downlink control channels, and the second set of reference signals is associated with a second set of serving physical downlink control channels.

6. The method of claim 1, wherein the indication of the second set of reference signals is received in a physical downlink shared channel scheduled via a physical downlink control channel, and the physical downlink control channel is associated with a reference signal of the second set of reference signals.

7. The method of claim 1, wherein a subset of the first set of reference signals and a subset of the second set of reference signals are associated with a third set of downlink antenna ports, and the third set of downlink antenna ports is a subset of the first set of downlink antenna ports and also a subset of the second set of downlink antenna ports.

8. The method of claim 7, further comprising computing a metric for radio link monitoring for the third set of downlink antenna ports by combining a first measurement of the subset of the first set of reference signals and a second measurement of the subset of the second set of reference signals.

9. The method of claim 1, further comprising:

transmitting the beam failure recovery request; and

receiving a response to the beam failure recovery request, wherein the response comprises configuration information corresponding to the second set of reference signals.

10. The method of claim 1, further comprising:

transmitting the beam failure recovery request for a source cell;

generating an indication of beam recovery failure in response to failing to receive a response to the beam failure recovery request within a configured time window;

initiating a connection reestablishment procedure comprising a selection of a target cell in response to the indication of the beam recovery failure;

retransmitting the beam failure recovery request for the source cell;

determining whether beam recovery corresponding to retransmitting the beam failure recovery request succeeds;

determining whether the connection reestablishment procedure with the target cell succeeds;

in response to the beam recovery succeeding and the connection reestablishment procedure being unsuccessful, maintaining a first connection with the source cell;

in response to the beam recovery being unsuccessful and the reestablishment procedure succeeding, establishing a second connection with the target cell;

in response to the beam recovery succeeding before the reestablishment procedure succeeds, maintaining the first connection with the source cell;

in response to the beam recovery succeeding after the reestablishment procedure succeeds, establishing the second connection with the target cell; and

in response to the beam recovery being unsuccessful and the reestablishment procedure being unsuccessful, entering an idle state.

11. The method of claim 1, wherein the at least one downlink antenna port associated with the at least one physical uplink control channel resource is at least partially co-located with at least one serving downlink antenna port.

12. The method of claim 11, further comprising transmitting a beam failure recovery request on the at least one physical uplink control channel resource based on a timing advance value associated with the at least one serving downlink antenna port.

13. The method of claim 11, further comprising transmitting a beam failure recovery request on the at least one physical random access channel resource if a timing advance value associated with the at least one serving downlink antenna port is not valid.

14. The method of claim 1, wherein a subset of the first set of reference signals is configured for beam failure detection, and the method further comprises detecting beam failure using the subset of the first set of reference signals.

15. An apparatus comprising:

a processor that measures a first set of reference signals for radio link monitoring; and

a receiver that receives an indication of at least one physical uplink control channel resource and at least one physical random access channel resource for transmitting a beam failure recovery request, wherein each of the at least one physical uplink control channel resource and the at least one physical random access channel resource are associated with at least one downlink antenna port;

wherein;

the processor determines an association between the at least one physical uplink control channel resource, the at least one physical random access channel resource, and the at least one downlink antenna port based on the indication of the at least one physical uplink control channel resource and the at least one physical random access channel resource for transmitting the beam failure recovery request;

the receiver receives an indication of a second set of reference signals for radio link monitoring;

the processor resets a counter in response to reception of the indication of the second set of reference signals, the first set of reference signals is associated with a first set of downlink antenna ports, the second set of reference signals is associated with a second set of downlink antenna ports, and the first set of downlink antenna ports is different from the second set of downlink antenna ports.

16. The apparatus of claim 15, wherein the processor:

generates a first in-sync indication or an out-of-sync indication based on measuring the first set of reference signals;

generates a second in-sync indication in response to reception of the indication of the second set of reference signals if a value of the counter is not zero;

increments the counter in response to generation of the out-of-sync indication, and

resets the counter in response to the first in-sync indication being generated or in response to the second in-sync indication being generated.

17. The apparatus of claim 15, wherein the processor:

initiates a radio link failure timer based on a result from measuring the first set of reference signals, wherein a radio link failure is identified in response to expiration of the radio link failure timer; and

stops the radio link failure timer in response to reception of the indication of the second set of reference signals.

18. The apparatus of claim 15, wherein the first and second sets of reference signals comprise a non-zero transmit power channel state information-reference signal, a synchronization signal and physical broadcast channel block, or some combination thereof.

19. The apparatus of claim 15, wherein the first set of reference signals is associated with a first set of serving physical downlink control channels, and the second set of reference signals is associated with a second set of serving physical downlink control channels.

20. The apparatus of claim 15, further comprising a transmitter, wherein:

the transmitter transmits the beam failure recovery request for a source cell;

the processor;

generates an indication of beam recovery failure in response to failing to receive a response to the beam failure recovery request within a configured time window; and

initiates a connection reestablishment procedure comprising a selection of a target cell in response to the indication of the beam recovery failure;

the transmitter retransmits the beam failure recovery request for the source cell;

the processor;

determines whether beam recovery corresponding to retransmitting the beam failure recovery request succeeds;

determines whether the connection reestablishment procedure with the target cell succeeds;

in response to the beam recovery succeeding and the connection reestablishment procedure being unsuccessful, maintains a first connection with the source cell;

in response to the beam recovery being unsuccessful and the reestablishment procedure succeeding, establishes a second connection with the target cell;

in response to the beam recovery succeeding before the reestablishment procedure succeeds, maintains the first connection with the source cell;

in response to the beam recovery succeeding after the reestablishment procedure succeeds, establishes the second connection with the target cell; and

in response to the beam recovery being unsuccessful and the reestablishment procedure being unsuccessful, the apparatus enters an idle state.