Physical layer procedures for lte in unlicensed spectrum

Patent metadata

Field	Value
Publication number	US-2016100433-A1
Application number	US-201514873079-A
Country	US
Kind code	A1
Filing date	Oct 1, 2015
Priority date	Oct 3, 2014
Publication date	Apr 7, 2016
Grant date	—

Abstract

The disclosure provides for control plane measurements in a wireless device. The wireless device may perform, on signals received over an unlicensed spectrum across multiple sub-frames, radio resource management (RRM) measurements of a cell. The wireless device may identify one or both of a first subset of the RRM measurements associated with a first subset of the sub-frames including opportunistic transmissions and a second subset of the RRM measurements associated with a second subset of the sub-frames including guaranteed transmissions. The wireless device may determine one or more RRM measurement values based on one or both of the first subset of the RRM measurements and the second subset of the RRM measurements. The wireless device may similarly perform radio link management (RLM) measurements and determine RLM measurement values based on the first and second subsets. The wireless device may also use timers for uplink transmissions to detect radio link failures.

First claim

What is claimed is:

1 . A method for performing control plane measurements in a wireless device, comprising:
performing, on signals received over an unlicensed spectrum across multiple sub-frames, radio resource management (RRM) measurements of a cell; identifying one or both of a first subset of the RRM measurements associated with a first subset of the sub-frames including opportunistic transmissions and a second subset of the RRM measurements associated with a second subset of the sub-frames including guaranteed transmissions; and determining one or more RRM measurement values based on one or both of the first subset of the RRM measurements and the second subset of the RRM measurements.

2 . The method of claim 1 , wherein:
performing the RRM measurements includes measuring reference signal received power (RSRP) to obtain RSRP measurements associated with the first subset of the sub-frames and RSRP measurements associated with the second subset of the sub-frames, and determining the one or more RRM measurement values includes combining, into a single RSRP value, the RSRP measurements associated with the first subset of the sub-frames and the RSRP measurements associated with the second subset of the sub-frames.

3 . The method of claim 1 , wherein:
performing the RRM measurements includes measuring a first received signal strength indicator (RSSI) associated with the first subset of the sub-frames and a second RSSI associated with the second subset of the sub-frames, and determining the one or more RRM measurement values includes determining a first reference signal received quality (RSRQ) value for the first subset of the sub-frames based on the first RSSI and determining a second RSRQ value for the second subset of the sub-frames based on the second RSSI.

4 . The method of claim 3 , further comprising comparing the first RSRQ value to a threshold value to detect an RRM event.

5 . The method of claim 3 , further comprising comparing the second RSRQ value to a received signal quality for a reference signal for a different cell to detect an RRM event.

6 . The method of claim 3 , further comprising receiving, from a network, an indication of which of the first RSRQ value and the second RSRQ value to use by the wireless device.

7 . A method for control plane measurements in a wireless device, comprising:
measuring, across multiple sub-frames received over an unlicensed spectrum, received cell-specific reference signals (CRS) from a cell to obtain CRS measurements; identifying one or both of a first subset of the CRS measurements associated with a first subset of the sub-frames including opportunistic transmissions and a second subset of the CRS measurements associated with a second subset of the sub-frames including guaranteed transmissions; computing one or both of a first signal to interference plus noise ratio (SINR) value for the first subset of the CRS measurements and a second SINR value for the second subset of the CRS measurements; and monitoring a radio link condition of the wireless device based at least in part on the first SINR value computed for the first subset of CRS measurements or the second SINR value computed for the second subset of CRS measurements.

8 . The method of claim 7 , wherein monitoring the radio link condition of the wireless device includes determining whether the wireless device is synchronized with the cell.

9 . The method of claim 7 , wherein monitoring the radio link condition of the wireless device includes:
determining that the first SINR value is available; and determining whether the wireless device is synchronized with the cell based on the first SINR value.

10 . The method of claim 7 , further comprising:
decoding a plurality of system information blocks (SIBs) broadcast by the cell; determining, for each of the SIBs, a decoding status indicating whether the decoding of a respective SIB was successful; and maintaining a first counter of decodings of the SIBs having an unsuccessful decoding status, and a second counter of decodings of the SIBs having a successful decoding status.

11 . The method of claim 10 , wherein monitoring the radio link condition of the wireless device includes:
determining that the first SINR value is not currently available or is unreliable; and determining that the wireless device is not synchronized with the cell in response to the first SINR value being not currently available or unreliable, the second SINR value indicating that the wireless device is not synchronized with the cell, and the first counter exceeding a threshold number of unsuccessful decodings.

12 . The method of claim 10 , wherein monitoring the radio link condition of the wireless device comprises:
determining that the first SINR value is not currently available or is unreliable; and determining that the wireless device is synchronized with the cell in response to the first SINR value being not currently available or unreliable, and the second SINR value indicating that the wireless device is synchronized with the cell or the second counter exceeding a threshold number of successful decodings.

13 . The method of claim 7 , further comprising declaring a radio link failure when monitoring the radio link condition of the wireless device indicates that the wireless device is not synchronized with the cell.

14 . An apparatus for performing control plane measurements in a wireless device, comprising:
a transceiver configured to receive signals over an unlicensed spectrum across multiple sub-frames; a memory; and a processor communicatively coupled to the transceiver and the memory, the processor and the memory configured to:
perform, on the signals received over the unlicensed spectrum across the multiple sub-frames, radio resource management (RRM) measurements of a cell;
identify one or both of a first subset of the RRM measurements associated with a first subset of the sub-frames including opportunistic transmissions and a second subset of the RRM measurements associated with a second subset of the sub-frames including guaranteed transmissions; and
determining one or more RRM measurement values based on one or both of the first subset of the RRM measurements and the second subset of the RRM measurements.

15 . The apparatus of claim 14 , wherein the processor and the memory are configured to:
measure reference signal received power (RSRP) to obtain RSRP measurements associated with the first subset of the sub-frames and RSRP measurements associated with the second subset of the sub-frames, and determine the one or more measurement values by combining, into a single RSRP value, the RSRP measurements associated with the first subset of the sub-frames and the RSRP measurements associated with the second subset of the sub-frames.

16 . The apparatus of claim 14 , wherein the processor and the memory are configured to:
measure a first received signal strength indicator (RSSI) associated with the first subset of the sub-frames and a second RSSI associated with the second subset of the sub-frames; and determine a first reference signal received quality (RSRQ) value for the first subset of the sub-frames based on the first RSSI and a second RSRQ value for the second subset of the sub-frames based on the second RSSI.

17 . The apparatus of claim 16 , wherein the processor and the memory are configured to compare the first RSRQ value to a threshold value to detect an RRM event to detect an RRM event.

18 . The apparatus of claim 16 , wherein the processor and the me

Assignees

• Qualcomm Inc

Inventors

• Vajapeyam Madhavan Srinivasan
• Damnjanovic Aleksandar
• Luo Tao
• Wei Yongbin
• Malladi Durga Prasad

Classifications

• H04W16/14 Primary

  Spectrum sharing arrangements {between different networks} · CPC title

• H04W56/0095

  estimated based on signal strength · CPC title

• H04L1/20

  using signal quality detector · CPC title

• H04L5/00

  Arrangements affording multiple use of the transmission path · CPC title

• H04B17/327 Primary

  Received signal code power [RSCP] · CPC title