Evolved node-B and methods for supporting co-existence with Wi-Fi networks in an unlicensed frequency band

Patent metadata

Field	Value
Publication number	US-9801207-B2
Application number	US-201414473008-A
Country	US
Kind code	B2
Filing date	Aug 29, 2014
Priority date	Nov 27, 2013
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

Embodiments of an eNB and method for supporting communication with UEs on an LTE network in an unlicensed frequency band are generally described herein. The eNB may be configured to transmit a first LTE signal that includes a first reference signal during an active transmission period of a Wi-Fi network in the unlicensed frequency band, and to restrict frequency spectra used for the transmission of the first LTE signal from frequency spectra used by the Wi-Fi network during the active transmission period. The first reference signal may enable maintenance of synchronization between the eNB and the UEs at least during the active transmission period. The eNB may be further configured to transmit a second LTE signal during a silence period of the Wi-Fi network in frequency spectra used by the Wi-Fi network during the active transmission period.

First claim

What is claimed is:

1. An Evolved Node-B (eNB) to communicate with one or more User Equipments (UEs) on a Long Term Evolution (LTE) network operating in an unlicensed frequency band, the eNB comprising:
a transceiver; and
hardware processing circuitry in communication with the transceiver arranged to:
cause the transceiver to transmit, in the unlicensed frequency band, a first LTE signal that includes a first reference signal during an active transmission period of a Wi-Fi network operating in the unlicensed frequency band;
restrict frequency spectra used for the transmission of the first LTE signal from frequency spectra used by the Wi-Fi network during the active transmission period of the Wi-Fi network, wherein the first reference signal enables maintenance of synchronization between the eNB and the one or more UEs at least during the active transmission period of the Wi-Fi network;
cause the transceiver to transmit a second LTE signal during a silence period of the Wi-Fi network, the second LTE signal transmitted in frequency spectra that includes at least a portion of the frequency spectra used by the Wi-Fi network during the active transmission period of the Wi-Fi network, the second LTE signal comprising a second reference signal; and
cause the transceiver to transmit a silence indicator that enables one or more of the UEs to determine an occurrence of at least one of a silence period or an active transmission period of the Wi-Fi network, the active transmission period being a time period that contains a transmission of a Wi-Fi device in the Wi-Fi network and the silence period being a time period that is free from transmission of the Wi-Fi device, the silence indicator comprising at least one of:
a time at which the at least one of the silence period or active transmission period occurs, or
an indication that the Wi-Fi network is currently in the silence period or active transmission period.

2. The eNB according to claim 1 , wherein the processing circuitry is further arranged to restrict the frequency spectra by selection of frequency spectra for transmission of the first LTE signal such that an LTE interference average power level caused to the frequency spectra used by the Wi-Fi network for transmission during the active transmission period of the network is not greater than one percent of an average transmit power level of the Wi-Fi network.

3. The eNB according to claim 1 , wherein:
the second LTE signal includes a second reference signal that enables determination of channel state information or maintenance of synchronization at the UEs; and
the transmission of the first reference signal is performed at an average power level at least 10 dB higher than the transmission of the second reference signal.

4. The eNB according to claim 3 , wherein:
the second LTE signal occupies more bandwidth than the second LTE signal, and to compensate for a bandwidth different, at least one of:
the first reference signal is longer than the second reference signal in time, and
the first reference signal is repeated.

5. The eNB according to claim 3 , wherein:
the second LTE signal is transmitted at a higher power than the second LTE signal, and to compensate for a different in transmission power, at least one of:
the first reference signal is longer than the second reference signal in time, and
the first reference signal is repeated.

6. The eNB according to claim 1 , wherein:
the first LTE signal is an orthogonal frequency division multiplexing (OFDM) signal comprising first resource elements (REs);
the second LTE signal is an OFDM signal comprising second REs; and
the transmission of the first reference signal includes transmission of first reference signal REs of the first LTE signal and the transmission of the second reference signal includes transmission of second reference signal REs of the second LTE signal.

7. The eNB according to claim 6 , wherein:
the transmission of the second LTE signal further includes transmission of a data signal;
the second REs are associated with time and frequency locations; and
the transmission of the data signal includes transmission of data REs of the second REs that are different in time location and frequency location than the second reference signal REs.

8. The eNB according to claim 1 , wherein the silence indicator is transmitted in a licensed frequency band that is disjoint from the unlicensed frequency band.

9. The eNB according to claim 1 , wherein:
the LTE, and Wi-Fi networks operate independently from each other; and
the hardware processing circuitry is further arranged to determine an occurrence of the silence period or the active transmission period of the Wi-Fi network based at least partially on reception of wireless signals transmitted from one or more Wi-Fi devices operating as part of the Wi-Fi network.

10. The eNB according to claim 1 , wherein the hardware processing circuitry is further arranged to:
determine transmission of the Wi-Fi device based at least partially on reception of a wireless signal transmitted from the Wi-Fi device; and
predict the at least one of the silence period or active transmission period from a pattern of the at least one of the silence period or active transmission period based on observations of previous transmissions of wireless signals from the Wi-Fi device along with knowledge about a Wi-Fi protocol used by the Wi-Fi network.

11. The eNB according to claim 1 , wherein the first and second LTE signals occupy different amounts of bandwidth.

12. The eNB according to claim 11 , wherein the second LTE signal occupies more bandwidth than the second LTE signal.

13. The eNB according to claim 11 , wherein the first and second LTE signals have different formats, a format of the first LTE signal based on a bandwidth of the first LTE signal and a bandwidth of the second LTE signal.

14. The eNB according to claim 1 , wherein the silence indicator is transmitted in another unlicensed frequency band that is different from the unlicensed frequency band.

15. The eNB according to claim 1 , wherein the hardware processing circuitry is further configured to determine on which band to transmit the silence indicator based on an amount of traffic on the licensed frequency band.

16. The eNB according to claim 1 , wherein:
the frequency spectra used by the Wi-Fi network during the active transmission period of the Wi-Fi network comprises a gap at at least one edge of the unlicensed frequency band, and the hardware processing circuitry is further configured to cause the transceiver to transmit the first LTE signal in the gap.

17. An Evolved Node-B (eNB) to communicate with one or more User Equipments (UEs) on a Long Term Evolution (LTE) network operating in an unlicensed frequency band, the eNB comprising:
a transceiver; and
hardware processing circuitry in communication with the transceiver and arranged to:
when it is determined that one or more Wi-Fi networks are operating in the unlicensed frequency band:
cause the transceiver to transmit a first LTE signal in the unlicensed frequency band during a silence period associated with the Wi-Fi networks;
cause the transceiver to refrain from transmitting LTE signals in the unlicensed frequency band used by the Wi-Fi network during an active transmission period associated with the Wi-Fi networks, the LTE signals transmitted in the unlicensed frequency band during the active transmission period, wherein the first LTE signal includes a first reference signal that enables maintenance of synchronization between the eNB and the UEs;
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Assignees

• Intel Corp

Inventors

• Sergeyev Vadim
• Bashar Shafi
• Davydov Alexei
• Fwu Jong-Kae

Classifications

• H04W72/51

  based on terminal or device properties · CPC title

• H04W72/21

  in the uplink direction of a wireless link, i.e. towards the network · CPC title

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04W88/06

  adapted for operation in multiple networks {or having at least two operational modes}, e.g. multi-mode terminals · CPC title

• H04W84/12

  WLAN [Wireless Local Area Networks] · CPC title