Method of transmitting reference signal in unlicensed spectrum for lte-laa system and wireless device using the same

Patent metadata

Field	Value
Publication number	US-2016277165-A1
Application number	US-201514919739-A
Country	US
Kind code	A1
Filing date	Oct 22, 2015
Priority date	Mar 20, 2015
Publication date	Sep 22, 2016
Grant date	—

Abstract

The disclosure is directed to method of transmitting a reference signal used by a wireless device in an unlicensed spectrum for a LTE-LAA communication system, and a wireless communication device using the same method. In one of the exemplary embodiments, the method would include not limited to receiving, via a first wireless receiver tuned to a licensed spectrum, a control message which at least indicates a pattern of a reference signal to be received; receiving, via a second wireless receiver tuned to an unlicensed spectrum, a first message which comprises the reference signal in the unlicensed spectrum; performing a measurement of the reference signal; generating a feedback based on the measurement of the reference signal; and transmitting, via a wireless transmitter tuned to the licensed spectrum, a second message which comprises the feedback of the reference signal in the licensed spectrum.

First claim

What is claimed is:

1 . A method of transmitting a reference signal used by a wireless device in an unlicensed spectrum for a Long Term Evolution (LTE) Licensed Assisted Access (LAA) communication system, the method comprising:
receiving, via a first wireless receiver tuned to a licensed spectrum, a control message which at least indicates a pattern of a reference signal to be received; receiving, via a second wireless receiver tuned to an unlicensed spectrum, a first message which comprises the reference signal in the unlicensed spectrum; performing a measurement of the reference signal; generating a feedback based on the measurement of the reference signal; and transmitting, via a wireless transmitter tuned to the licensed spectrum, a second message which comprises the feedback of the reference signal in the licensed spectrum.

2 . The method of claim 1 , wherein the reference signal is a part of a first cluster of at least three consecutive transmissions of identical reference signals.

3 . The method of claim 1 , wherein the control message includes at least a cancellation message to cancel a second cluster of reference signal.

4 . The method of claim 3 , wherein the cancellation message further indicates a number of clusters of reference signals to be cancelled.

5 . The method of claim 1 , wherein the control message includes at least a deference message for deferring the receiving of the reference signal.

6 . The method of claim 5 , wherein the deference message further indicates a duration of the deferring the receiving of the reference signal.

7 . The method of claim 2 , wherein the control message includes at least a transmission status report which includes a bitmap that indicates at least a first reference signal of the first cluster of reference signals to be received and at least a second reference signal of the first cluster of reference signals to be cancelled.

8 . The method of claim 2 , wherein the control message includes at least a transmission status report which includes a number of reference signals of the first cluster to be cancelled.

9 . The method of claim 8 , wherein the transmission status report aggregates multiple reports in response to be the unlicensed spectrum being unavailable for a previous transmission.

10 . The method of claim 1 , wherein the control signal is received from a primary serving cell (Pcell), and the reference signal is received from a secondary serving cell (Scell).

11 . The method of claim 1 , wherein the control message is decoded from a physical layer control channel (PDCCH) within which a new RNTI is used to identify the control message for a group of LAA wireless devices.

12 . The method of claim 1 , wherein the control message is at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a cell specific reference signal (CRS), a channel state information-reference signal (CSI-RS), a discovery reference signal (DRS).

13 . The method of claim 12 , wherein there is a time gap between consecutive transmissions, wherein the time gap is greater or equal to zero.

14 . The method of claim 13 , wherein a duration of the cluster is greater than access times of all other devices in the unlicensed spectrum but is less than the limit set by the regional government regulatory agency.

15 . The method of claim 14 , wherein the duration between the cluster and a next cluster is configured by the control message.

16 . The method of claim 13 , wherein the control message configures a number of consecutive transmissions of the cluster.

17 . The method of claim 13 , wherein the control message configures a first time duration between a start of a reference signal and a start of a next repeated reference signal.

18 . The method of claim 17 , wherein the control message configures a second time duration between an end of a reference signal and a start of a next repeated reference signal.

19 . The method of claim 18 , wherein the first time duration and the second time duration is configured by at least one of an absolute time, a number of subframes, a number of frames, a number of physical layer time slots, and a number of OFDM symbols.

20 . A wireless device comprising:
a first wireless receiver tuned to a licensed spectrum; a second wireless receiver tuned to an unlicensed spectrum; a wireless transmitter tuned to the licensed spectrum; and a processor coupled to the first wireless receiver, the second wireless receiver, and the wireless transmitter, wherein the processor is configured at least for:
receiving, via a first wireless receiver tuned to a licensed spectrum, a control message which at least indicates a pattern of a reference signal to be received;
receiving, via a second wireless receiver tuned to an unlicensed spectrum, a first message which comprises the reference signal in the unlicensed spectrum;
performing a measurement of the reference signal;
generating a feedback based on the measurement of the reference signal; and
transmitting, via a wireless transmitter tuned to the licensed spectrum, a second message which comprises the feedback of the reference signal in the licensed spectrum.

Assignees

• Acer Inc

Inventors

• Wei Hung-Yu

Classifications

• H04L5/0048 Primary

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title

• H04L5/0001

  Arrangements for dividing the transmission path (two-way operation using the same type of signal, i.e. duplex H04L5/14) · CPC title

• H04W16/14 Primary

  Spectrum sharing arrangements {between different networks} · CPC title

• H04L27/0006

  Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio (for spectrum sharing between different networks H04W16/14) · CPC title

• H04W72/12

  Wireless traffic scheduling · CPC title