U.S. patent application number 17/306102 was filed with the patent office on 2021-08-19 for method and apparatus for transmitting and receiving signals in a frequency band.
The applicant listed for this patent is Telefonaktiebolaget LM Ericsson (publ). Invention is credited to Johan Bergman, Gary Boudreau, Muhammad Ali Kazmi.
Application Number | 20210258959 17/306102 |
Document ID | / |
Family ID | 1000005555140 |
Filed Date | 2021-08-19 |
United States Patent
Application |
20210258959 |
Kind Code |
A1 |
Kazmi; Muhammad Ali ; et
al. |
August 19, 2021 |
Method and Apparatus for Transmitting and Receiving Signals in a
Frequency Band
Abstract
There is provided a method and apparatus for transmitting and
receiving signals in a frequency band in a wireless communications
network. The method comprises determining a frequency separation
between a frequency of a transmit signal and a frequency of a
receive signal within the frequency band based on at least one of a
power of the transmit signal, a number of physical channels
associated with the transmit signal, and a number of physical
channels associated with the receive signal. The method further
comprises transmitting and receiving signals in the frequency band
in accordance with the determined frequency separation. The method
may be performed by a User Equipment of a Network Node.
Inventors: |
Kazmi; Muhammad Ali;
(Stockholm, SE) ; Bergman; Johan; (Stockholm,
SE) ; Boudreau; Gary; (Ottawa, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Telefonaktiebolaget LM Ericsson (publ) |
Stockholm |
|
SE |
|
|
Family ID: |
1000005555140 |
Appl. No.: |
17/306102 |
Filed: |
May 3, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15207182 |
Jul 11, 2016 |
11026229 |
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17306102 |
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PCT/EP2016/052078 |
Feb 1, 2016 |
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15207182 |
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62110928 |
Feb 2, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 52/367 20130101;
H04L 5/0066 20130101; H04W 76/27 20180201; H04L 5/14 20130101; H04W
88/02 20130101; H04W 72/0453 20130101; H04L 5/143 20130101 |
International
Class: |
H04W 72/04 20060101
H04W072/04; H04L 5/14 20060101 H04L005/14; H04W 76/27 20060101
H04W076/27; H04W 52/36 20060101 H04W052/36 |
Claims
1. A method for transmitting and receiving signals in a frequency
band in a wireless communications network, the method comprising:
determining a frequency separation between a frequency of a
transmit signal and a frequency of a receive signal within the
frequency band based on at least one of a power of the transmit
signal, a number of physical channels associated with the transmit
signal, and a number of physical channels associated with the
receive signal; and transmitting and receiving signals in the
frequency band in accordance with the determined frequency
separation.
2. The method of claim 1, wherein the method is performed by a User
Equipment.
3. The method of claim 2, wherein the transmit signal is an uplink
signal, from the User Equipment to a network node; and the receive
signal is a downlink signal, from the network node to the User
Equipment.
4. The method of claim 2, wherein determining the frequency
separation comprises: selecting a transmit-receive frequency
separation value from at least two predefined transmit-receive
frequency separation values based on at least one of a power of the
transmit signal, a number of physical channels associated with the
transmit signal, and a number of physical channels associated with
the receive signal.
5. The method of claim 4, wherein selecting the transmit-receive
frequency separation value comprises: comparing at least one of a
parameter indicative of a power of the transmit signal, a parameter
indicative of a number of physical channels associated with the
receive signal, and a parameter indicative of a number of physical
channels associated with the receive signal with a threshold; and
selecting the transmit-receive frequency separation value from the
plurality of predefined transmit-receive frequency separation
values based on the comparison.
6. The method of claim 2, wherein the determined frequency
separation is associated with at least one of a respective maximum
transmit power of the User Equipment, a respective maximum number
of uplink physical channels, and a respective maximum number of
downlink physical channels.
7. The method of claim 2, wherein transmitting and receiving
signals in the frequency band in accordance with the determined
frequency separation comprises the User Equipment adapting its
transmitter and or receiver based on the determined frequency
separation.
8. The method of claim 2, further comprising scheduling
transmission of uplink data using the determined frequency
separation.
9. The method of claim 1, wherein the method is performed by a
network node.
10. The method of claim 9, wherein the transmit signal is an uplink
signal, from a User Equipment to the network node, and the receive
signal is a downlink signal, from the network node to the User
Equipment.
11. The method of claim 10, further comprising signalling the
determined frequency separation to the User Equipment.
12. The method of claim 11, wherein the signalling comprises an
identifier identifying the determined frequency separation.
13. The method of claim 11, wherein the determined frequency
separation is signalled to the User Equipment in Radio Resource
Control (RRC) signalling or Layer 1 signalling.
14. The method of claim 11, wherein the determined frequency
separation is signalled to the User Equipment as part of scheduling
information.
15. The method of claim 10, wherein transmitting and receiving
signals in the frequency band in accordance with the determined
frequency separation comprises the network node adapting its
transmitter and or receiver based on the determined frequency
separation.
16. The method of claim 10, further comprising scheduling
transmission of downlink data and or uplink data using the
determined frequency separation.
17. The method of claim 2, wherein the User Equipment is capable of
full-duplex Frequency Division Duplex (FDD) operation.
18. The method of claim 2, wherein the User Equipment is capable of
narrowband operation.
19. The method of claim 1, wherein the physical channels are
Physical Resource Blocks (PRBs) or Resource Elements (REs).
20. The method of claim 1, wherein the determined frequency
separation is a minimum transmit-receive carrier frequency
separation.
21. A User Equipment comprising: a receiver; and a transmitter;
wherein the User Equipment is operable to: determine a frequency
separation between a frequency of a transmit signal and a frequency
of a receive signal within a frequency band in a wireless
communications network based on at least one of a power of the
transmit signal, a number of physical channels associated with the
transmit signal, and a number of physical channels associated with
the receive signal; and transmit and receive signals in the
frequency band in accordance with the determined frequency
separation.
22. A network node comprising: a receiver; and a transmitter;
wherein the network node is operable to: determine a frequency
separation between a frequency of a transmit signal and a frequency
of a receive signal within a frequency band in a wireless
communications network based on at least one of a power of the
transmit signal, a number of physical channels associated with the
transmit signal, and a number of physical channels associated with
the receive signal, and transmit and receive signals in the
frequency band in accordance with the determined frequency
separation.
23. The network node of claim 22, wherein the transmit signal is an
uplink signal, from a User Equipment to the network node, and the
receive signal is a downlink signal, from the network node to the
User Equipment, wherein the network node is further operable to
signal the determined frequency separation to the User Equipment.
Description
TECHNICAL FIELD
[0001] Embodiments described herein relate to methods and apparatus
for transmitting and receiving signals in a frequency band.
Embodiments described herein relate to a network node and a User
Equipment.
BACKGROUND
Machine-Type Communication
[0002] Machine-to-machine (M2M) communication (or also referred to
as Machine-type communication (MTC)) is used for establishing
communication between machines and between machines and humans. The
communication may comprise exchange of data, signaling, measurement
data, configuration information, etc. The device size may vary from
that of a wallet to that of a base station. The M2M devices are
quite often used for applications like sensing environmental
conditions (e.g., temperature reading), metering or measurement
(e.g., electricity usage, etc.), fault finding or error detection,
etc. In these applications the M2M devices are active very seldom
but over a consecutive duration depending upon the type of service
e.g., about 200 milliseconds, once every 2 seconds, about 500
milliseconds, every 60 minutes, etc. The M2M device may also do
measurement on other frequencies or other RATs (Radio Access
Technologies).
[0003] One category of M2M devices is referred to as a low cost
device. For example, the cost reduction can be realized by having
just a single receiver in the UE (User Equipment). The cost can be
further reduced by having a single receiver and half duplex FDD
capability. The latter feature prevents the need for having a
duplex filter since the UE does not transmit and receive at the
same time.
[0004] Another category of M2M devices is required to support
enhanced UL (Uplink) and/or DL (downlink) coverage. These devices
are installed at locations where path loss between the M2M device
and the base station can be very large such as when used as a
sensor or metering device located in a remote location such as a
basement of a building. In such scenarios the reception of signal
from the base station is very challenging. For example, the path
loss can be worse than 15-20 dB compared to normal operation. To
cope with such challenges, the coverage in uplink and/or in
downlink has to be substantially enhanced. This can be realized by
employing one or a plurality of techniques in the UE and/or in the
radio network node for enhancing the coverage e.g., boosting of DL
transmit power, boosting of UL transmit power, enhanced UE
receiver, signal repetition, etc.
Narrowband MTC Operation
[0005] For narrowband MTC operation, it is possible that the MTC UE
can be scheduled with less than 6 physical resource blocks (PRBs)
and that a minimum allocation of 1 PRB for both the uplink (UL) and
downlink (DL) can be supported. Furthermore, it is expected that
retuning of the frequency of MTC UE will be required to support
frequency multiplexing of users and to support frequency
hopping.
SUMMARY
[0006] For existing LTE UE categories, the filtering requirements
have been defined based on the transmit-to-receive frequency
separation for a given band class (also referred to as frequency
band), as defined in Table 5.7.4 of TS36.101 3GPP E-UTRA User
Equipment Radio Transmission and Reception version 12.5.0 release
12, as well as the defined RF performance requirements of the given
LTE UE category.
[0007] The context of the transmit-receive frequency separation is
illustrated in FIG. 1, for frequency division duplexing (FDD)
operation. FIG. 1 illustrates a narrowband MTC UE transmit-receive
frequency separation. Use of a narrower transmit-receive frequency
separation than specified in Table 5.7.4 of TS36.101 may result in
levels of self-interference between the MTC UE transmitter and
receiver that exceed the ability of the filtering requirements of
the MTC UE to allow it to meet the needed performance. This may
result in degradation in the MTC UE performance (for example, in
the error rate performance of the MTC UE, loss of bit rate,
throughput) and/or a reduction in the coverage capabilities of the
MTC UE. For example, the MTC UE may not be able to operate in cell
border region or when it is far from the serving base station. Such
a situation can occur if the UL and DL PRB allocations for FD (Full
Duplex) FDD transmissions are assigned independently and, for
example, with reference to FIG. 1, the assigned UL PRBs are close
to the upper edge of the UL band and the assigned DL resources are
close to the lower edge of the DL band. In such a case, if the band
gap is significantly smaller than the permitted minimum
transmit-receive carrier frequency separation, the duplexer
filtering may not be sufficient to ensure the specified performance
of the UE.
[0008] Based on the above new requirements being defined for MTC
UE's, the minimum transmit-receive frequency separation may be less
than specified in Table 5.7.4 of TS36.101. Furthermore, the MTC UE
could also be transmitting with full power in a narrow bandwidth
close to the band edge. Table 5.7.4-1 of TS36.101 is shown in FIG.
2.
[0009] The present inventors have appreciated that it may be
desirable to define a minimum separation between the transmit
frequency and receive frequency within the band for narrowband
operation of MTC, in order to ensure that the duplexer gap is
sufficient to support existing performance requirements. For
half-duplex FDD and TDD MTC UE's it is not expected to be an issue;
however, full-duplex FDD MTC UE's will need to take in to
consideration the transmit-frequency separation impact on RF
performance including reference sensitivity and to maintain the
required coverage improvements for MTC UEs. If the performance
requirements cannot be met by the duplexing for transmit-receive
separation of less than a given threshold, it may also be possible
to specify a reduction in transmit power to compensate
accordingly.
[0010] FIG. 3 is a Table showing some examples of duplexer distance
versus band gap for band classes 3, 8 and 20 in LTE. From these
examples it can be seen that the band gap can be considerably less
than the duplexer distance (i.e., the minimum transmit-receive
frequency separation as per Table 5.7.4-1 of TS36.101 shown in FIG.
2).
[0011] The base station (BS) implementation in terms of its ability
to suppress self-interference experienced at its own receiver due
to downlink transmissions towards the UE also has limitations.
Therefore, the use of a narrower transmit-receive frequency
separation may also result in levels of self-interference from the
BS transmitter to its own receiver that exceed the ability of the
filtering requirements of the BS serving the MTC UE. This may
result in degradation in the performance of the BS (e.g., lower
throughput) and/or a reduction in the uplink coverage when serving
one or more MTC UEs.
[0012] According to some embodiments of the present invention,
there is provided a method for transmitting and receiving signals
in a frequency band in a wireless communications network. This
method comprises determining a frequency separation between a
frequency of a transmit signal and a frequency of a receive signal
within the frequency band based on at least one of a power of the
transmit signal, a number of physical channels associated with the
transmit signal, and a number of physical channels associated with
the receive signal. The method further comprises transmitting and
receiving signals in the frequency band in accordance with the
determined frequency separation.
[0013] Embodiments of the present invention have the advantage that
radio resources may be used more efficiently without unacceptably
degrading User Equipment/network node performance.
[0014] According to an embodiment, the method may be performed by a
User Equipment. In this embodiment, the transmit signal may be an
uplink signal, from the User Equipment to a network node; and the
receive signal may be a downlink signal, from the network node to
the User Equipment.
[0015] In some embodiments, determining the frequency separation
may comprise selecting a transmit-receive frequency separation
value from at least two predefined transmit-receive frequency
separation values based on at least one of a power of the transmit
signal, a number of physical channels associated with the transmit
signal, and a number of physical channels associated with the
receive signal.
[0016] In some embodiments, selecting the transmit-receive
frequency separation value may comprise: comparing at least one of
a parameter indicative of a power of the transmit signal, a
parameter indicative of a number of physical channels associated
with the receive signal, and a parameter indicative of a number of
physical channels associated with the receive signal with a
threshold; and selecting the transmit-receive frequency separation
value from the plurality of predefined transmit-receive frequency
separation values based on the comparison.
[0017] The determined frequency separation may be associated with
at least one of a respective maximum transmit power of the User
Equipment, a respective maximum number of uplink physical channels,
and a respective maximum number of downlink physical channels.
[0018] In some embodiments, transmitting and receiving signals in
the frequency band in accordance with the determined frequency
separation may comprise the User Equipment adapting its transmitter
and or receiver based on the determined frequency separation.
[0019] The method may further comprise scheduling transmission of
uplink data using the determined frequency separation.
[0020] According to a further embodiment of the present invention,
the method may be performed by a network node. In this embodiment,
the transmit signal may be an uplink signal, from a User Equipment
to the network node, and the receive signal may be a downlink
signal, from the network node to the User Equipment.
[0021] The method may further comprise signalling the determined
frequency separation to the User Equipment. In some embodiments,
the signalling may comprises an identifier identifying the
determined frequency separation. For example, the determined
frequency separation may be signalled to the User Equipment in
Radio Resource Control (RRC) signalling or Layer 1 signalling.
According to an embodiment, the determined frequency separation may
be signalled to the User Equipment as part of scheduling
information.
[0022] In some embodiments, transmitting and receiving signals in
the frequency band in accordance with the determined frequency
separation may comprise the network node adapting its transmitter
and or receiver based on the determined frequency separation.
[0023] The method may further comprise scheduling transmission of
downlink data and or uplink data using the determined frequency
separation.
[0024] In embodiments, the User Equipment may be capable of
full-duplex Frequency Division Duplex (FDD) operation.
[0025] In embodiments, the User Equipment may be capable of
narrowband operation.
[0026] The physical channels may be Physical Resource Blocks (PRBs)
or Resource Elements (REs).
[0027] The determined frequency separation may be a minimum
transmit-receive carrier frequency separation.
[0028] According to the present invention, there is also provided a
User Equipment comprising a receiver and a transmitter. The User
Equipment is operable to determine a frequency separation between a
frequency of a transmit signal and a frequency of a receive signal
within a frequency band in a wireless communications network based
on at least one of a power of the transmit signal, a number of
physical channels associated with the transmit signal, and a number
of physical channels associated with the receive signal. The User
Equipment is further operable to transmit and receive signals in
the frequency band in accordance with the determined frequency
separation.
[0029] According to the present invention, there is also provided a
network node comprising a receiver and a transmitter. The network
node is operable to determine a frequency separation between a
frequency of a transmit signal and a frequency of a receive signal
within a frequency band in a wireless communications network based
on at least one of a power of the transmit signal, a number of
physical channels associated with the transmit signal, and a number
of physical channels associated with the receive signal. The
network node is further operable to transmit and receive signals in
the frequency band in accordance with the determined frequency
separation.
[0030] Some embodiments of the present invention have the following
advantages: [0031] The use of adaptive transmit-receive frequency
separation on the average may enable the use of available radio
resources (e.g., UL and DL subframes) more efficiently when the MTC
UE transmits in a narrowband mode using the UL and DL time
resources; [0032] The network node may be able to assign more radio
resources for scheduling the data to the UE; [0033] The network
node may have less constraint in terms of scheduling data to the UE
as on the average fewer time resources are wasted or are unused
[0034] On the average the UE may have more measurement
opportunities due to fewer unused or wasted UL and DL time
resource.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Embodiments of the present invention will now be described,
by way of example only, with reference to the Figures:
[0036] FIG. 1 illustrates a narrowband MTC UE transmit-receive
frequency separation;
[0037] FIG. 2 shows Table 5.7.4-1 of TS36.101 3GPP E-UTRA User
Equipment Radio Transmission and Reception;
[0038] FIG. 3 is a Table showing some examples of duplexer distance
versus band gap for band classes 3, 8 and 20 in LTE;
[0039] FIG. 4 is a flow chart showing an embodiment of the present
invention;
[0040] FIG. 5 is a flow chart showing a preferred embodiment of the
present invention;
[0041] FIG. 6 is a flow chart showing a preferred embodiment of the
present invention;
[0042] FIG. 7 illustrates an example telecommunications
network;
[0043] FIG. 8 shows a user equipment according to an embodiment of
the present invention;
[0044] FIG. 9 shows a network node according to an embodiment of
the present invention.
DETAILED DESCRIPTION
[0045] In the description of some embodiments the non-limiting term
UE (user equipment) is used. The UE herein can be any type of
wireless device capable of communicating with a network node or
another UE over radio signals. The UE may also be a radio
communication device, target device, device-to-device (D2D) UE,
machine type UE or UE capable of machine to machine communication
(M2M), a sensor equipped with UE, iPAD, Tablet, mobile terminals,
smart phone, laptop embedded equipped (LEE), laptop mounted
equipment (LME), USB dongles, Customer Premises Equipment (CPE),
etc.
[0046] Also in the description of some embodiments generic
terminology, "radio network node" or simply "network node (NW
node)", is used. The "radio network node" or "network node" can be
any kind of network node which may comprise a base station, radio
base station, base transceiver station, base station controller,
network controller, evolved Node B (eNB), Node B, relay node,
access point, radio access point, Remote Radio Unit (RRU) Remote
Radio Head (RRH), etc.
[0047] The embodiments are described by considering LTE. However,
the embodiments are applicable to any RAT (Radio Access Technology)
or multi-RAT systems, where the UE receives and/or transmit signals
(e.g., data) e.g., LTE FDD/TDD, WCDMA/HSPA, GSM/GERAN, Wi Fi, WLAN,
CDMA2000, etc.
[0048] FIG. 4 is a flow chart showing an embodiment of the present
invention. At 400 the method comprises determining a frequency
separation between a frequency of a transmit signal and a frequency
of a receive signal within a frequency band based on at least one
of a power of the transmit signal, a number of physical channels
associated with the transmit signal, and a number of physical
channels associated with the receive signal. At 410 the method
comprises transmitting and receiving signals in the frequency band
in accordance with the determined frequency separation.
[0049] FIG. 5 is a flow chart showing an embodiment of the present
invention. In this preferred embodiment, the method described with
respect to FIG. 4 is performed by a User Equipment. However, the
method described with respect to FIG. 4 may also be performed by a
network node, as will be described later with respect to FIG.
6.
[0050] The "transmit signal" may be an uplink signal, from the User
Equipment to a network node; and the "receive signal" may be a
downlink signal, from the network node to the User Equipment.
[0051] The step 400 of determining the frequency separation may
comprise at 402 selecting a transmit-receive frequency separation
value from at least two predefined transmit-receive frequency
separation values based on at least one of a power of the transmit
signal, a number of physical channels associated with the transmit
signal, and a number of physical channels associated with the
receive signal.
[0052] In some embodiments, step 402, selecting the
transmit-receive frequency separation value may comprise at 404
comparing at least one of a parameter indicative of a power of the
transmit signal, a parameter indicative of a number of physical
channels associated with the receive signal, and a parameter
indicative of a number of physical channels associated with the
receive signal with a threshold; and at 406 selecting the
transmit-receive frequency separation value from the plurality of
predefined transmit-receive frequency separation values based on
the comparison.
[0053] The determined frequency separation may be associated with
at least one of a respective maximum transmit power of the User
Equipment, a respective maximum number of uplink physical channels,
and a respective maximum number of downlink physical channels.
[0054] In some embodiments, step 410 transmitting and receiving
signals in the frequency band in accordance with the determined
frequency separation may comprise at 412 the User Equipment
adapting its transmitter and or receiver based on the determined
frequency separation.
[0055] The method may further comprise at 420 scheduling
transmission of uplink data using the determined frequency
separation.
[0056] FIG. 6 is a flow chart showing a further preferred
embodiment of the invention. In this further preferred embodiment,
as mentioned above, the method described with respect to FIG. 4 is
performed by a network node.
[0057] Similarly, the "transmit signal" may be an uplink signal,
from a User Equipment to the network node, and the "receive signal"
may be a downlink signal, from the network node to the User
Equipment.
[0058] Although not shown in FIG. 6, the network node may determine
the desired frequency separation using the method described above
with respect to FIG. 5, steps 402, 404 and 406.
[0059] In some embodiments, the method may further comprise the
network node, at 602, signalling the determined frequency
separation to the User Equipment. The signalling may comprise an
identifier identifying the determined frequency separation. Thus,
step 602, may comprise, at 604, sending an identifier identifying
the determined frequency separation to the User Equipment.
[0060] The determined frequency separation may be signalled to the
User Equipment in Radio Resource Control (RRC) signalling or Layer
1 signalling. For example, in some preferred embodiments, the
determined frequency separation may be signalled to the User
Equipment as part of scheduling information.
[0061] In some embodiments, step 410 transmitting and receiving
signals in the frequency band in accordance with the determined
frequency separation may comprise at 612 the network node adapting
its transmitter and or receiver based on the determined frequency
separation.
[0062] The method may further comprise at 620 scheduling
transmission of downlink data and or uplink data using the
determined frequency separation.
[0063] In some embodiments, the User Equipment may be capable of
full-duplex Frequency Division Duplex (FDD) operation. The User
Equipment may be capable of narrowband operation.
[0064] The determined frequency separation may be a minimum
transmit-receive carrier frequency separation. The frequency band
may be a predefined frequency band.
[0065] In some embodiments, the physical channels may be Physical
Resource Blocks (PRBs) or Resource Elements (REs).
[0066] Embodiments of the present invention will now be described
in more detail below.
[0067] Some embodiments comprise a method to dynamically configure
the minimum separation between transmit and receive frequencies in
MTC UE's. The minimum separation in transmit-receive frequencies
can be specified as a network node configurable parameter or be
specified as one value from a possible set of pre-defined
parameters provided in the relevant standard. Furthermore, the
maximum transmit power of the MTC UE may also be configurable in
combination with the minimum frequency separation distance.
[0068] The minimum transmit-receive frequency separation may be a
function of the number of physical channels (e.g., PRB) scheduled
to be transmitted in the UL (uplink) by the MTC UE.
[0069] Steps which may be performed by a MTC capable UE served by a
network node comprise: [0070] Obtaining an adaptive
transmit-receive frequency separation parameter (.DELTA.f) out of
at least two values of transmit-receive frequency separation
(.DELTA.f1 and .DELTA.f2) by comparing at least one parameter
indicative of the band gap of the bandclass being employed by the
UE, and possibly a second parameter indicative of the transmit
power and a possibly third parameter indicative of the number of
physical channels (e.g., PRBs, REs, etc.) being transmitted or
expected to be transmitted at a given time index between the UE and
the network node (e.g., transmit power, received signal strength,
signal measurement such as pathloss) with a threshold (T); [0071]
Using the obtained adaptive transmit-receive frequency separation
parameter to identify the allowed physical channels (e.g., PRBs,
REs, etc.) and/or transmit power that can be transmitted by the MTC
UE in combination with a defined transmit power level.
[0072] For example, the UE may further adapt its radio transmitter
and/or receiver based on the determined value of the .DELTA.f, and
the UE may further communicate with the network node using the
determined value of the .DELTA.f and the values of the associated
parameters.
[0073] As an additional embodiment, an exception to the minimum
transmit-receive frequency separation may be allowed if frequency
hopping is employed at a hopping rate above a given threshold.
[0074] Steps performed by a network node serving a FD-FDD capable
UE may comprise: [0075] Obtaining at least one parameter (e.g.,
bandwidth or number of PRBs to be simultaneous transmitted) related
to an adaptive transmit-receive frequency separation parameter
(.DELTA.f) out of at least two values of transmit-receive frequency
separation (.DELTA.f1 and .DELTA.f2), by comparing at least one
parameter indicative of the band gap of the bandclass being
employed by the UE, and possibly a second parameter indicative of
the transmit power and a possibly third parameter indicative of the
number of physical channels (e.g., PRBs, REs, etc.) being
transmitted or expected to be transmitted at a given time index
between the UE and the network node (e.g., transmit power, received
signal strength, signal measurement such as pathloss) with a
threshold (T); and which parameter is used by the UE for
determining the transmit-receive frequency separation (.DELTA.f)
between UL and DL time resources. [0076] Signaling the obtained at
least one parameter to the UE for enabling it to configure the
time-frequency distance between UL and DL time resources to be
transmitted and received as UL and DL radio signals respectively
and/or the combination of transmit-receive distance and allowed
transmit power to be employed by the UE. [0077] Adapting
(optionally) its radio transmitter and/or receiver based on the
determined value of the .DELTA.f, and may further communicate with
the UE using the determined value of the .DELTA.f and the values of
the associated parameters used by the UE.
[0078] The following describes, by way of example only: [0079] An
embodiment involving adaptively selecting the transmit-receive
frequency separation for transmission of UL and DL physical
resource blocks (PRBs) in UEs. [0080] A method in a UE of obtaining
and applying adaptive selection of transmit-receive frequency
separation for transmission of UL and DL physical resource blocks
(PRBs) in UEs. [0081] A method in a network node of determining the
adaptive selection of transmit-receive frequency separation for
transmission of UL and DL physical resource blocks. [0082] A method
in a UE comprising signalling capability related to obtaining and
applying adaptive selection of transmit-receive frequency
separation for transmission of UL and DL physical resource
blocks
Description of a Scenario Involving Adaptive Transmit-Receive
Frequency Separation
[0083] The scenario comprises at least one UE 710 served by a cell
720 (also referred to as serving cell or PCell of the UE) managed,
controlled or served by a network node 700, For example, as shown
in FIG. 7. The serving cell operates on a carrier frequency (f1).
If the UE is capable of multi-carrier (also referred to as carrier
aggregation) the UE may also be served by a plurality of serving
cells e.g., primary cell (PCell) and one or more secondary cells
(SCells). In some embodiments a dual connectivity capable UE may be
configured with a PCell and at least a PSCell (primary SCell) and
may also be configured with one or more SCells. The PCell, PSCell
and SCell(s) may be managed, controlled or served by the same
network node or by different network nodes. The following
embodiments though described for one serving cell are applicable to
a UE served by any number serving cells. In case of multiple
serving cells, the UE and/or network node serving the UE may apply
the procedures disclosed herein independently for each cell.
[0084] In embodiments, the UE operates in full duplex FDD where UL
and DL transmission occur in the time resources e.g., in the same
subframes. The UL and DL time resource may operate on the same or
different carrier frequencies.
[0085] The terms transmit-receive frequency separation, TX-RX or
RX-TX carrier center frequency separation, TX-RX or RX-TX frequency
separation, UL-DL or DL-UL frequency separation, duplexer gap,
duplex gap, band separation, duplex spacing, band gap, etc., may be
interchangeably used but they all refer to the same concept and
meaning i.e., the separation in frequency between the simultaneous
transmission and reception of physical channels. Non-limiting
examples of physical channels are time-frequency resource, radio
channels, resource elements (REs), physical resource blocks (PRBs),
resource blocks (RBs), virtual resource blocks (VRBs).
[0086] Embodiments may apply to any UE which is capable of FD-FDD
operation or UE which is FD-FDD capable. Embodiments may also apply
to only certain frequency bands supported by the FD-FDD capable UE
or for all bands supported by the FD-FDD capable UE. Examples of
certain frequency FD-FDD bands for which embodiments may apply
(e.g., by means of pre-defined rule) are bands with specific
frequency and/or radio characteristics. Examples of such bands are:
bands whose frequencies are above a threshold (e.g., above 2 GHz),
bands whose duplex gap is below a threshold (e.g., below 60 MHz),
bands whose passband is larger than a threshold (e.g., 50 MHz or
above), etc.
Method in a UE of Obtaining and Applying Adaptive Time-Frequency
Separation for UL-DL Time Resource
[0087] In this embodiment, the steps performed by a MTC capable UE
served by a network node comprise: [0088] Obtaining an adaptive
transmit-receive frequency separation parameter (.DELTA.f) out of
at least two values of transmit-receive frequency separation
(.DELTA.f 1 and .DELTA.f 2) by comparing at least one parameter
indicative of transmit power and possibly a second parameter
indicative of the number of physical channels (e.g., PRBs) being
transmitted or expected to be transmitted at a given time index
between the UE and the network node (e.g., transmit power, received
signal strength, signal measurement such as pathloss) with a
threshold (T); [0089] Using the obtained adaptive transmit-receive
frequency separation parameter to identify the allowed PRBs that
can be transmitted by the MTC UE at a defined power level.
[0090] The UE may implicitly or explicitly obtain information
related to the transmit-receive frequency separation (.DELTA.f)
between UL and DL time resources (also referred to as UL-DL
frequency separation), and use the obtained information to
determine the frequency location of allowed PRBs to be transmitted
meeting the allowed transmit-receive frequency separation
requirement.
[0091] The UE may perform the following: [0092] Obtaining
information related to the default transmit-receive frequency
separation for the given bandclass or carrier being employed as
well as the default maximum transmit power; [0093] Determining the
minimum transmit-receive frequency separation and/or maximum
transmit power based on the obtained information; and [0094]
Employing the minimum transmit-receive frequency separation and/or
maximum transmit power during the scheduling and transmission of UL
data by the UE.
[0095] The above steps which may be performed by the UE in any
order are described below.
[0096] Obtaining information related to transmit-receive frequency
separation--In this step, the UE obtains implicit or explicit
information that can be used for determining the allowed
transmit-receive frequency separation (.DELTA.f) and/or maximum
transmit power to be assumed or used by the UE. The UE may use one
or plurality of obtained information for determining the
transmit-receive frequency separation (.DELTA.f).
[0097] The determined value of .DELTA.f based on the obtained
information may further be associated with the maximum number of UL
and/or DL physical channels (e.g., UL/DL RBs) and/or maximum
transmit power which can be used by the UE for UL transmission.
[0098] The implicit and/or explicit information to be obtained and
used by the UE for determining the transmit-receive frequency
separation (.DELTA.f) may be one or more of the following:
pre-defined, selected by the UE autonomously or explicitly
indicated by the network node to the UE as further explained
below.
[0099] Examples of implicit information are: [0100] Band class
(also referred to as frequency band) the UE is employing; [0101]
Default transmit-receive frequency separation of bandclass employed
by the UE; [0102] Band gap of bandclass employed by the UE. For
example, the UE may select and use shorter or the shortest
magnitude of .DELTA.f provided the duplex gap is above a threshold,
otherwise it may use the longer or the longest magnitude of
.DELTA.f; [0103] Roll-off of filtering or emission mask in use;
[0104] Required transmission rate (e.g., target or expected bit
rate) for the UL and DL of the MTC device. For example, the UE may
select and use shorter or the shortest magnitude of .DELTA.f
provided the transmission rate is below a threshold; [0105]
Modulation order or type being employed or to be used by the UL and
DL transmissions of the UE. Examples of modulation order are QPSK,
16 QAM, 64 QAM, 256 QAM, etc. For example, the UE may select and
use shorter or the shortest magnitude of .DELTA.f provided
modulation order is below a threshold (e.g., 16QAM), otherwise it
may use the longer or the longest magnitude of .DELTA.f; [0106]
Channel quality or signal quality between MTC UE and serving
network node e.g., RSRQ, SINR, SNR, BLER, etc., measurements
obtained from the UE or based on UE feedback signals such as
ACK/NACK at the MTC UE. For example, the UE may select and use
shorter or the shortest magnitude of .DELTA.f provided signal
quality is above a threshold (e.g., RSRQ is above -10 dB),
otherwise it may use the longer or the longest magnitude of
.DELTA.f; [0107] Current physical distance between the UE and the
serving network node. For example, the UE may select and use
shorter or the shortest magnitude of .DELTA.f provided the physical
distance is above a threshold (e.g., 500 meters), otherwise it may
use the longer or the longest magnitude of .DELTA.f; [0108] UE
speed or velocity e.g., UE speed expressed in Doppler (such as 30
Hz), rate of change of distance (such as 50 km/hr). For example,
the UE may select and use shorter or the shortest magnitude of
.DELTA.f provided the speed is below a threshold (e.g., Doppler
frequency is below 10 Hz), otherwise it may use the longer or the
longest magnitude of .DELTA.f; [0109] Cell size of the serving cell
or maximum distance between base station and cell edge e.g., cell
range, cell radius; [0110] Power class of the serving base station
e.g., maximum power of the BS such as 46 dBm, 30 dBm, 24 dBm, 20
dBm, etc.; [0111] Type of serving base station e.g., wide area BS,
medium range BS, local area base station, home base station, etc.;
[0112] Type of cell topology or cell deployment type e.g., macro
cell, micro cell, pico cell, femto cell, etc.; [0113] Configured
maximum UE transmit power e.g., power below 0 dBm means a smaller
cell and Therefore, use of a smaller transmit-receive frequency
separation (.DELTA.f) may be permitted; [0114] UE transmit emission
mask; [0115] UE receive filter characteristics; [0116] UE Rx-Tx
frequency difference measurement performed by the UE; [0117] eNode
B Rx-Tx frequency difference measurement performed by the network
node; [0118] Signal strength between UE and the network node e.g.,
path loss, RSRP, etc., measurements obtained from the UE. For
example, the UE may select and use shorter or the shortest
magnitude of .DELTA.f provided the path loss is above a threshold
(e.g., path loss is above 70 dB), otherwise it may use the longer
or the longest magnitude of .DELTA.f; [0119] Known position or
geographical location of UE and network node. Their positions can
be determined by using one or more positioning method. Examples are
GNSS/A-GNSS (e.g., GPS or A-GPS), OTDOA based RSTD measurements,
E-CID, radio fingerprinting or any other known cellular positioning
technology, from which relative round trip delay between the UE and
the network node can be calculated; [0120] Frequency hopping is
employed. For example, the UE may select and use shorter or the
shortest magnitude of .DELTA.f provided frequency hopping is
employed for which the hopping rate is above a given threshold,
otherwise it may use the longer or the longest magnitude of
.DELTA.f;
[0121] Examples of explicit information are: [0122] Indication or
permission from the network node to use certain value of the
transmit-receive frequency separation (.DELTA.f) out of two or more
pre-defined values when one or more criteria are met. [0123]
transmit power of the UE. The transmit power can be any one or more
of: averaged transmit power, peak transmit power in one or more
slots or subframes or frames, power headroom (i.e., difference
between configured maximum transmit power and power to be
transmitted in dB), expected transmit power or current or
instantaneous transmit power, etc.; [0124] index or location of
physical channels (e.g., location of PRBs in frequency domain) to
be employed for transmission and/or reception of signals by the UE;
[0125] Number of physical channels (e.g., number of PRBs) to be
employed for transmission and/or reception of signals by the
UE.
[0126] The above obtained implicit or explicit information may be
valid for each scheduled instance of UL and DL time resources or it
may be applicable over a certain validity time (.DELTA.T1) (e.g.,
(.DELTA.T1=500 ms). The parameter .DELTA.T1 may be applicable from
a reference time (T1), where T1 can be the time instant at which
the UE obtains the parameter (.DELTA.f).
[0127] Any of the above information (e.g., implicit or explicit
information or their validity time) may be obtained by the UE by
one or more of the following means: [0128] Autonomously by the UE
e.g., based on radio measurements, by retrieving it from the
memory; [0129] Receiving from the network node e.g., via higher
layer signaling such as serving network node signaling the
switching time to be used; [0130] Receiving from another UE if UE
is capable of performing device to device (D2D) operation and in
case the other D2D UE has any of this information (e.g., it
acquired from the network node); [0131] Pre-defined information
e.g., two or more pre-defined transmit-receive frequency separation
values such as (.DELTA.f)=20 MHz or (.DELTA.f)=30 MHz can be used
depending on one or more criteria.
[0132] Determining transmit-receive frequency separation based on
obtained information--In this step, the UE determines the actual
transmit-receive frequency separation to be used by the UE for
scheduled UL and DL physical channels e.g., UL/DL PRBs.
[0133] If the UE obtains a value of the transmit-receive frequency
separation explicitly from the network node then it may apply the
obtained value for subsequent scheduled UL and DL physical channels
e.g., UL/DL PRBs.
[0134] If the UE obtains any one or more implicit information for
determining the transmit-receive frequency separation then the UE
uses the obtained information (e.g., one or more pre-defined sets
of information, UE selected or indicated by the network node) for
determining the actual value of the transmit-receive frequency
separation.
[0135] The determination at the UE is typically done by comparing
one or more obtained information or parameters with one or more
thresholds (H) and based on the comparison of the parameter with
the thresholds, selects one of the two or more predefined values of
the transmit-receive frequency separation. The threshold(s) may be
pre-defined or received from the network node e.g., via higher
layer signaling such as via RRC or MAC.
[0136] The determination of the transmit-receive frequency
separation (.DELTA.f) can also be based on a function.
[0137] An example of a general function is:
(.DELTA.f)=f(.DELTA.f1,.DELTA.f2, . . . ,.DELTA.f,P1,P2, . . .
Pj,H1,H2, . . . H.sub.j)
where .DELTA.fi is one of the pre-defined transmit-receive
frequency separation values, the parameter Pi is one of the
parameters (e.g., maximum power, maximum UL physical channels that
UE can transmit, max DL physical channels that UE can receive,
etc.) and Hi is the threshold to compare the parameter Pi.
[0138] The above generalized function or mechanism in the UE to
derive the transmit-receive frequency separation to be used is
described by various examples below.
[0139] The relation or mapping between the comparison of the one or
more obtained parameters with their respective obtained
threshold(s) and the corresponding transmit-receive frequency
separation to be selected based on comparison by the UE can be
pre-defined. This is also explained with several examples
below:
[0140] In one embodiment the UE may obtain one or more parameters
that implicitly or explicitly indicate the minimum transmit-receive
frequency separation, maximum transmit power and also the maximum
number of UL and/or DL physical channels (e.g., UL or DL RBs) that
the UE may use in combination with the minimum transmit-receive
frequency separation. An example is illustrated in table 1 below
for combinations of each of the minimum transmit-receive frequency
separation as well as the maximum UL RBs that can be transmitted by
the UE. In this example P1 is a parameter indicative of the maximum
power and P2 is a parameter indicative of the maximum UL RBs. The
UE then compares the value of the obtained parameters P1 and P2
with a least one threshold (H) and (B) respectively. Based on the
valid combination of P1 and P2, the minimum transmit-receive
frequency separation is determined.
TABLE-US-00001 TABLE 1 Determination of one of the `m` pre-defined
minimum transmit- receive frequency separation values by the UE
Determination of minimum transmit-receive frequency separation and
maximum Result of transmit power of the UE comparing Result of
parameter comparing Determined Frequency (P1) with parameter
minimum transmit- Separation Transmit threshold (P2) with receive
frequency ID Power ID (H) threshold (B) separation (.DELTA.f) 0 0
P1 < H P2 < B K frequency resources (MHz) 1 0 P1 < H P2
.gtoreq. B L frequency resources (MHz) 2 1 P1 .gtoreq. H P2 < B
M frequency resources (MHz) 3 1 P1 .gtoreq. H P2 .gtoreq. B N
frequency resources (MHz)
[0141] In another example, the UE may obtain one or more parameters
that implicitly or explicitly indicate the minimum transmit-receive
frequency separation and use them for determining one of the three
possible values of transmit-receive frequency separation. This
example is illustrated in Table 2 below. This is similar to the
example in table 1 except that in this case the UE may use up to
two threshold values (H1 and H2) for comparing it with the obtained
parameter (P) that is implicitly or explicitly indicative of the
said transmit-receive frequency separation (.DELTA.f). An example
is illustrated in table 2 for combinations of each of the minimum
transmit-receive frequency separation as well as the maximum UL RBs
that can be transmitted by the UE. In this example, P1 is a
parameter indicative of the maximum power and P3 is a parameter
indicative of the maximum UL RBs. The UE then compares the value of
the obtained parameters P1 with at least two thresholds (H1 and H2)
and the parameter P3 with at least one threshold (B1) respectively.
Based on the valid combination of P1 and P3, the minimum
transmit-receive frequency separation is determined as shown in
table 2.
TABLE-US-00002 TABLE 2 Determination of one of the three
pre-defined minimum transmit-receive frequency separation values
with two pre-defined transmit power input values by the UE
Determination of minimum transmit-receive frequency separation and
maximum transmit power of the UE Result of Result of comparing
comparing parameter parameter Determined Frequency (P1) with (P3)
with minimum transmit- Separation Transmit thresholds threshold
receive frequency ID Power ID (H1, H2) (B1) separation (.DELTA.f) 0
0 P1 < H1 P3 < B1 K frequency resources (MHz) 1 0 P1 < H1
P3 .gtoreq. B1 L frequency resources (MHz) 2 0 H1 < P1 < H2
P3 < B1 M frequency resources (MHz) 3 1 H1 < P1 < H2 P3
.gtoreq. B1 N frequency resources (MHz) 4 1 P1 .gtoreq. H2 P2 <
B1 Q frequency resources (MHz) 5 1 P1 .gtoreq. H2 P3 .gtoreq. B1 R
frequency resources (MHz)
[0142] In yet another embodiment the UE may obtain one or more
parameters that implicitly or explicitly indicate the minimum
transmit-receive frequency separation as well as the maximum
transmit power that the UE may use in combination with the minimum
transmit-receive frequency separation. Similar to the examples
above the parameters obtained by the UE may be employed to
determine one of 2, 3 or in general n combinations of minimum
transmit-receive frequency separation and maximum transmit power.
An example is illustrated in table 3 below for 2 combinations of
each of the minimum transmit-receive frequency separation as well
as the maximum transmit power. In this example P4 is a parameter
indicative of the minimum transmit-receive frequency separation and
P5 is a parameter indicative of the maximum rated transmit power of
the UE (i.e., 23 dBm or 31 dBm). The UE then compares the value of
the obtained parameters P4 and P5 with a least one threshold (H3)
and (B2) respectively. Based on the valid combination of P4 and P5,
the minimum transmit-receive frequency separation and maximum
allowed transmit power combination is chosen from the values K or L
and Y or Z respectively. Note that the maximum allowed power can be
a value less than the maximum rated power of the UE.
TABLE-US-00003 TABLE 3 Determination of one of the 2 pre-defined
minimum transmit-receive frequency separation values combined with
2 allowed maximum transmit power levels for the UE Determination of
minimum transmit- receive frequency separation and maximum transmit
power of the UE Result of Result of comparing comparing Determined
Frequency parameter parameter minimum transmit- Separation Transmit
(P4) with (P5) with receive frequency ID Power ID threshold (H3)
threshold (B2) separation (.DELTA.f) 0 0 P4 < H3 P5 < B2 K
frequency resources (MHz) , Y dBm transmit power 1 0 P4 < H3 P5
.gtoreq. B2 K frequency resources (MHz), Z dBm transmit power 2 1
P4 .gtoreq. H3 P5 < B2 L frequency resources (MHz) , Y dBm
transmit power 3 1 P4 .gtoreq. H3 P5 .gtoreq. B2 L frequency
resources (MHz), Z dBm transmit power
[0143] The above examples can be generalized similar to the
previous examples in tables 1, 2, 3 (and tables 4 and 5 below),
except that in the general case the UE may use up to (n-1)
threshold values (H1, H2, . . . Hn-1) for the parameter indicative
of the minimum transmit-receive frequency separation and (n-1)
threshold values (J1, J2, . . . Jn-1) for the parameter indicative
of the maximum transmit power for comparison with the obtained
parameters (P1 and P2) that are implicitly or explicitly indicative
of the said minimum transmit-receive frequency separation as well
as the maximum transmit power respectively. Based on this
comparison the UE determines one of the n values for the minimum
transmit-receive frequency and one of the n values for the maximum
transmit power.
[0144] In yet another example, as illustrated in table 4 below, the
transmit-receive frequency separation is selected based on UE
transmit power e.g., current power, expected power, power headroom,
maximum power to be used by the UE, etc. In this example P6 is a
parameter indicative of the UE transmit power of the UE (i.e., 10
dBm) or power headroom e.g., 20 dB. The UE then compares the value
of the obtained parameter P6 with a threshold (B3) respectively.
Based on the valid comparison of P6, the minimum transmit-receive
frequency separation is chosen from the values K and L.
TABLE-US-00004 TABLE 4 Determination of one of the 2 pre-defined
minimum transmit-receive frequency separation values based on UE
transmit power levels for the UE Determination of minimum transmit-
receive frequency separation and maximum transmit power of the UE
Result of comparing Determined minimum parameter transmit-receive
Frequency (P6) with frequency separation Separation Transmit
threshold (.DELTA.f) and maximum ID Power ID (B3) transmit power 0
0 P6 < B3 K frequency resources (MHz) 1 1 P6 .gtoreq. B3 L
frequency resources (MHz)
[0145] In yet another example, as illustrated in table 5 below, the
transmit-receive frequency separation is selected based on UL
and/or DL physical channels for use by the UE e.g., current RBs
used, expected RBs to be used, maximum RBs to be used by the UE,
etc. In this example P7 is a parameter indicative of the RBs for
use by the UE (i.e., 5 RBs) or the fraction of RBs with respect to
total RBs in the cell bandwidth. The UE then compares the value of
the obtained parameter P7 with a threshold (B4) respectively. Based
on the valid comparison of P7, the minimum transmit-receive
frequency separation is chosen from the values K and L.
TABLE-US-00005 TABLE 5 Determinationof one of the 2 pre-defined
minimum transmit-receive frequency separation values based on
number of UL and/or DL physical channels for the UE Determination
of minimum transmit- receive frequency separation and maximum
transmit power of the UE Result of comparing Determined minimum
parameter transmit-receive Frequency (P7) with frequency separation
Separation Transmit threshold (.DELTA.f) and maximum ID Power ID
(B4) transmit power 0 0 P7 < B4 K frequency resources (MHz) 1 1
P7 .gtoreq. B4 L frequency resources (MHz)
[0146] In yet another example, as illustrated in Table 6 below, the
transmit-receive frequency separation is selected based on whether
frequency hopping is employed at a rate above a given threshold. In
this example P8 is a parameter indicative of the rate of frequency
hopping (e.g., hopping at least once every subframe) The UE then
compares the value of the obtained parameter P8 with a threshold
(B5) respectively. Based on the valid comparison of P8, the minimum
transmit-receive frequency separation is chosen from the values K
and L.
TABLE-US-00006 TABLE 6 Determination of one of the 2 pre-defined
minimum transmit-receive frequency separation values based on use
of frequency hopping by the UE Determination of minimum transmit-
receive frequency separation and maximum transmit power of the UE
Result of comparing Determined minimum parameter transmit-receive
Frequency (P8) with frequency separation Separation Transmit
threshold (.DELTA.f) and maximum ID Power ID (B5) transmit power 0
0 P8 < B5 K frequency resources (MHz) 1 1 P8 .gtoreq. B5 L
frequency resources (MHz)
[0147] In some embodiments, in case the UE is not able to obtain
the needed information related to the minimum transmit-receive
frequency separation or maximum transmit power, e.g., during an
initialization phase, the UE adopts a predefined default value
instead until it is able to obtain the needed information. It may
also be chosen that the UE will assume a pre-defined value for
minimum transmit-receive frequency separation or maximum transmit
power, in case it does not obtain the above values or associated
information to determine the minimum transmit-receive frequency
separation or maximum transmit power.
[0148] In some embodiments, the UE applies a hysteresis in the
comparison between a parameter value and a threshold in order to
avoid unnecessarily frequent changes between parameter settings,
e.g., due to statistical fluctuations in measurement values.
Employing the Minimum Transmit-Receive Frequency Separation and
Transmit Power
[0149] Upon acquiring the minimum transmit-receive frequency
separation and/or maximum transmit power as described in the
previous section, the UE employs these parameters when selecting
PRBs to be transmitted.
[0150] Note that scheduling of PRBs may be determined by eNB,
however the UE may autonomously schedule the PRBs as well.
[0151] The term acquiring herein may comprise any of receiving,
acquiring, determining, selecting, retrieving or obtaining the
minimum transmit-receive frequency separation and/or maximum
transmit power or associated information (such as scheduling) i.e.,
by any one or more of: autonomously, based on a pre-defined rule
for receiving from another node (e.g., UE or network node). The UE
may also retrieve from its memory the minimum transmit-receive
frequency separation and/or maximum transmit power acquired
previously or at any earlier time. In this case the UE may also
determine if the retrieved minimum transmit-receive frequency
separation and/or maximum transmit power is applicable for use with
the current UL and DL time resources. For example, the UE may
determine if the validity time for using the retrieved or acquired
minimum transmit-receive frequency separation and/or maximum
transmit power is still valid e.g., validity timer (e.g., 500 ms)
has not yet expired. The value of the timer may also be adapted
based on UE speed e.g., shorter value of the timer at higher UE
speed (such as above 50 km/hr).
[0152] The UE also acquires the information related to the next
scheduling instance between UL and DL time resources to be
performed and/or the pattern of such scheduling applicable over
certain time period (e.g., frame or multiple frames or periodic
pattern, etc.). The UE may acquire this information based on any
one or more of: [0153] scheduling data on UL and/or DL time
resources by the network node; [0154] semi-static or
semi-persistent scheduling pattern for physical signals or channels
configured by the network node; [0155] any kind of periodic or
aperiodic pattern of scheduling of data on UL and DL time resources
by the network node.
[0156] If the acquired minimum transmit-receive frequency
separation and/or maximum transmit power values are valid then the
UE uses the acquired information related to these values at the
next scheduling occurrence. The UE may also store the statistics
related to the minimum transmit-receive frequency separation or
maximum transmit power used for performing the scheduling and use
it in future time e.g., for reporting the statistics to the network
node.
Method in a Network Node of Determining and Configuring a UE with
Adaptive Minimum Transmit-Receive Frequency Separation and Maximum
Transmit Power
[0157] The steps which may be performed by a network node serving a
FD-FDD capable UE comprise: [0158] Obtaining at least one parameter
(e.g., bandwidth or number of PRBs to be simultaneous transmitted)
related to an adaptive transmit-receive frequency separation
parameter (.DELTA.f), which can be a function of the at least two
values of transmit-receive frequency separation (.DELTA.f1 and
.DELTA.f2), and which parameter is used by the UE for determining
the transmit-receive frequency separation (.DELTA.f) between UL and
DL time resources. Furthermore, obtaining at least one combination
of transmit-receive frequency separation and allowed transmit power
to be employed by the UE for a given transmit-receive frequency
separation. [0159] Signaling the obtained at least one parameter to
the UE for enabling it to configure the time-frequency distance
between UL and DL time resources to be transmitted and received as
UL and DL radio signals respectively and/or the combination of
transmit-receive distance and allowed transmit power to be employed
by the UE.
[0160] In this context, the network node implicitly or explicitly
obtains information related to the minimum transmit-receive
frequency separation parameter (.DELTA.f and/or maximum transmit
power to be used by the UE for scheduling and transmitting UL PRBs.
The determined value of .DELTA.f based on the obtained information
may further be associated with the maximum number of UL and/or DL
physical channels (e.g., UL/DL RBs) and/or maximum transmit power
which can be used by the UE for UL transmission. The association
may also be pre-defined. Therefore, the UE can also determine the
maximum number of UL and/or DL physical channels (e.g., UL/DL RBs)
and/or maximum transmit power based on the value of .DELTA.f
received from the network node and the pre-defined association.
[0161] The network node may also configure its own UL signal
reception from the UE and DL signal transmission towards the UE
based on the determined value of .DELTA.f for the UE. This will
allow the network node to perform radio communication with the UE
which is configured to operate using the determined value of
.DELTA.f.
[0162] The network node may also configure the UE with information
which allows the UE to determine when to employ the indicated
minimum transmit-receive frequency separation parameter (.DELTA.f)
and/or maximum transmit power for scheduling of UL PRBs.
[0163] Steps which may be performed by the network node comprise:
[0164] Obtaining information related to the minimum
transmit-receive frequency separation parameter (.DELTA.f) and or
the maximum transmit power. [0165] Signaling this information to
assist the UE in determining the permitted PRBs to transmit data on
and the maximum transmit power that can be employed.
[0166] An additional or optional step performed by the network node
comprises: [0167] Configuring the UE with UL and/or DL time
resources and the permitted maximum transmit power.
[0168] The above steps, which may be performed in any order, are
described below.
[0169] Obtaining information related to frequency separation--In
this step, the network node determines the minimum transmit-receive
frequency separation parameter (.DELTA.f) and/or the maximum
transmit power to be used by the UE.
[0170] The network uses one or more of the following information to
determine which minimum transmit-receive frequency separation
and/or the maximum transmit power should be used by the UE or any
implicit information to be used by the UE for determining these
values. Examples of such information to be used the network node
are the same as described above.
[0171] Depending upon the type of the information, the network node
obtains the above information based on any one or more of the
following: [0172] Measurement performed by the network node itself
on at least the signals transmitted by the UE; [0173] Pre-defined
information; [0174] Measurement performed by the UE.
[0175] The network node based on the above information may
determine the minimum transmit-receive frequency separation and/or
the maximum transmit power to be used by the UE. The network node
may also determine the threshold value to be used by the UE for
determining the minimum transmit-receive frequency separation
and/or the maximum transmit power based on a comparison between one
or more parameters (P) which is indicative of the frequency
separation and transmit power of the UE and the respective
thresholds (H).
[0176] The network node may use a similar comparison between one or
more parameters (Pi) and thresholds (Hi, Bi) as used by the UE for
determining the frequency separation and maximum transmit power.
Therefore, examples in tables 1, 2, 3, 4, 5 and 6 are also
applicable for use by the network node.
[0177] Signaling information to assist the UE based on obtained
information--Upon determining the frequency separation and/or
transmit power to be used by the UE, the network node may signal
one or more pieces of information to the UE that assists the UE to
use or itself determine the frequency separation and transmit power
of the UE.
[0178] The network node may or may not signal the determined
frequency separation and/or transmit power to the UE. If the
network node signals the frequency separation and/or transmit power
to the UE then it may signal either the absolute value of the
frequency separation and/or transmit power or it may signal only
the identifier of the determined frequency separation and/or
transmit power. In the latter case, both identifiers and the
corresponding frequency separation and/or transmit power can be
pre-defined; this is shown in examples in tables 1-3.
[0179] For example, the network node may also decide to signal only
the threshold(s) to be used by the UE for comparing P with H to
obtain the frequency separation and/or transmit power.
[0180] In case the network node signals the determined frequency
separation and/or transmit power, the UE uses it for scheduling and
transmitting UL resources. On the other hand, if the network node
signals implicit information to the UE such as thresholds and/or
type of parameters to be used by the UE for determining the
frequency separation and/or transmit power, then the UE uses the
received information and the pre-defined relations for determining
the frequency separation and/or transmit power.
[0181] The network node may also signal information related to the
validity time over which the signaled parameters or associated
information is valid. This can be realized by configuring a timer
at the UE. For example, the UE can be configured that the
information related to the frequency separation and/or transmit
power is valid for use by the UE up to 500 milliseconds from the
moment the information is received at the UE. In another example it
may be pre-defined or configured by the network node at the UE that
the information related to the frequency separation and/or transmit
power is valid for performing up to Z (e.g., Z=1, Z=10, etc.)
number of transitions between UL-DL time resources.
[0182] Any one or more of the above information can be provided to
the UE using higher layer signaling (e.g., RRC, MAC, etc.) or in
lower layer signaling (e.g., L1 channels such as PDCCH, etc.). The
information may also be signaled as part of the scheduling
information.
[0183] The network node (also referred to as transmitting network
node) may also signal one or more set of the above information
related to one or plurality of the UEs to another network node
(also referred to as receiving network node), e.g., a neighboring
eNode B over X2 interface. The receiving network node may use the
received information for determining one or more parameters related
to the frequency separation and/or transmit power to be used for
its own UEs and/or the received information be used for the UEs
after their cell change from the transmitting network node.
[0184] In some embodiments, in case the network is not able to
signal the information to assist the UE, e.g., during an
initialization phase, the network assumes that the UE is applying a
predefined default value instead until it is able to obtain the
assistance information from the network. It may also be pre-defined
that the UE will assume a pre-defined value for frequency
separation and/or transmit power in case it does not obtain the
frequency separation and/or transmit power or associated
information to drive or obtain the frequency separation and/or
transmit power. In another example the pre-defined default value
can be the smallest of the pre-defined values. The network will in
such a situation determine the frequency separation and/or transmit
power based on the pre-defined rule and adapts its scheduling as
will be described later.
[0185] In some embodiments, the network applies a hysteresis in the
comparison between a parameter value and a threshold in order to
avoid unnecessarily frequent changes between different frequency
separation and/or transmit power values e.g., due to statistical
fluctuations in measurement values.
[0186] Configuring UE with UL and DL time resources--The network
node schedules the data for UL transmission and DL transmission on
UL time resource and DL time resource respectively. The scheduling
can be done on a subframe basis, e.g., sending a scheduling grant
on the PDCCH. The network node may also pre-configure the UE with a
pattern of UL and DL time resources for UL and DL transmissions
respectively. The scheduling information acquired by the UE is used
by the UE for transmission on the UL and reception on the DL.
[0187] According to another embodiment, the network node also
adapts it's scheduling to account for the currently used frequency
separation and/or transmit power.
Method in a UE Signaling Capability Related to Obtaining and
Applying Adaptive Frequency Separation and/or Transmit Power
[0188] According to this embodiment, a UE signals a capability
information to another node (a network node such as base station,
eNode B, relay, core network (MME), another UE capable of D2D
operation, etc.) to inform whether the UE is capable of acquiring
and using or applying information related to the minimum
transmit-receive frequency separation and/or transmit power. More
specifically, the UE capability information may indicate whether
the UE is capable of obtaining and using adaptive frequency
separation and/or transmit power, wherein the adaptation is done by
selecting between at least two values of switching times. More
generally the UE may indicate whether it has the capability to
obtain one or more parameters related to the frequency separation
and/or transmit power, use them to determine the frequency
separation and/or transmit power and use the determined frequency
separation and/or transmit power for scheduling and transmitting
data. i.e., whether UE is capable of any of the procedures
described above. The capability information is sent via higher
layer signaling (e.g., RRC signaling) to the network node. The
information may be sent during initial call setup or after cell
change (e.g., handover, etc.) or during the session or call.
[0189] The UE capability information may also contain additional or
more specific information such as: [0190] UE is capable of
autonomously determining the adaptive frequency separation and/or
transmit power e.g., based on pre-defined parameters and/or rules,
and using the determined frequency separation and/or transmit power
for switching; [0191] UE is capable of determining the adaptive
frequency separation and/or transmit power based on information
received from the network node e.g., threshold for comparing with
the determined parameter to find the frequency separation and/or
transmit power, and using the determined frequency separation
and/or transmit power values; [0192] UE is capable of determining
the adaptive frequency separation and/or transmit power based on
any combination of: information received from the network node
and/or another UE, pre-defined parameters and/or rules, and
autonomous determination by the UE, and using the determined
frequency separation and/or transmit power values; [0193] the
frequency bands for which the UE is capable of performing any one
or more of the above.
[0194] The acquired UE capability information may be used by the
network node (e.g., eNode B, base station, etc.) for performing one
or more radio operation tasks or network management tasks: [0195]
The tasks comprise forwarding the received UE capability
information to another network node which may use it after cell
change of the UE. [0196] The network node may store the received
capability information and use it in future e.g., when the same UE
performs switching or returns to be served by the network node.
[0197] The network node may also decide based on the received
information whether to configure or signal any information related
to the frequency separation and/or transmit power or any
information which may assist the UE in determining or using the
frequency separation and/or transmit power. For example, if the UE
needs to receive the frequency separation and/or transmit power as
it cannot determine it autonomously, then the network node itself
determines the frequency separation and/or transmit power and
signals the determined value to the UE.
[0198] In general, the idea according to some embodiments of the
present invention is that a UE or network node determines an
adaptive transmit-receive frequency separation parameter (.DELTA.f)
out of at least two values of transmit-receive frequency separation
(.DELTA.f1 and .DELTA.f2) for a frequency band, based on one or
more criteria (e.g., pre-defined rule, transmit power, etc.). The
determined value of the .DELTA.f is associated with at least one
of: a maximum number of UL and/or DL RBs, and maximum UE transmit
power allowed by the UE when using the determined value of the
.DELTA.f. The network node may also signal the determined value of
the .DELTA.f to the UE. The UE and the network node may further
adapt their respective radio transmitters and/or receivers based on
the determined value of the .DELTA.f. The UE and the network node
communicate with each using the determined value of the .DELTA.f
and the values of the associated parameters.
[0199] FIG. 8 shows a User Equipment 800 according to an embodiment
of the present invention. The User Equipment 800 comprises a
receiver 810 and a transmitter 820. According to embodiments of the
present invention, the User Equipment 800 is operable, e.g., using
processing circuitry comprising a controller or processor
configured with appropriate firmware and/or software, stored in
memory associated with the controller or processor, to determine a
frequency separation between a frequency of a transmit signal and a
frequency of a receive signal within a frequency band in a wireless
communications network based on at least one of a power of the
transmit signal, a number of physical channels associated with the
transmit signal, and a number of physical channels associated with
the receive signal. The User Equipment 810 is further operable to
transmit and receive signals in the frequency band in accordance
with the determined frequency separation. The frequency band may be
a predefined frequency band.
[0200] The transmit signal may be an "uplink signal", from the User
Equipment to a network node; and the receive signal may be a
"downlink signal", from the network node to the User Equipment.
[0201] In some embodiments, the User Equipment 800 may be operable
to determine the frequency separation by selecting a
transmit-receive frequency separation value from at least two
predefined transmit-receive frequency separation values based on at
least one of a power of the transmit signal, a number of physical
channels associated with the transmit signal, and a number of
physical channels associated with the receive signal. The at least
two predefined transmit-receive frequency separation values may be
stored in the User Equipment's memory (not shown).
[0202] In some embodiments, the User Equipment 800 may be operable
to select the transmit-receive frequency separation value by
comparing at least one of a parameter indicative of a power of the
transmit signal, a parameter indicative of a number of physical
channels associated with the receive signal, and a parameter
indicative of a number of physical channels associated with the
receive signal with a threshold; and selecting the transmit-receive
frequency separation value from the plurality of predefined
transmit-receive frequency separation values based on the
comparison.
[0203] The determined frequency separation may be associated with
at least one of a respective maximum transmit power of the User
Equipment 800, a respective maximum number of uplink physical
channels, and a respective maximum number of downlink physical
channels.
[0204] The User Equipment 800 may further be operable to adapt its
transmitter and or receiver based on the determined frequency
separation.
[0205] The User Equipment 800 may further be operable to schedule
transmission of uplink data using the determined frequency
separation.
[0206] The User Equipment 800 may be capable of full-duplex
Frequency Division Duplex (FDD) operation. The User Equipment 800
may be capable of narrowband operation.
[0207] The physical channels may be Physical Resource Blocks (PRBs)
or Resource Elements (REs).
[0208] The determined frequency separation may be a minimum
transmit-receive carrier frequency separation.
[0209] FIG. 9 shows a network node 900 according to an embodiment
of the present invention. The network node 900 comprises a receiver
910 and a transmitter 920. The network node 900 is operable, e.g.,
using processing circuitry comprising a controller or processor
configured with appropriate firmware and/or software, stored in
memory associated with the controller or processor, to determine a
frequency separation between a frequency of a transmit signal and a
frequency of a receive signal within a frequency band in a wireless
communications network based on at least one of a power of the
transmit signal, a number of physical channels associated with the
transmit signal, and a number of physical channels associated with
the receive signal. The network node 900 is further operable to
transmit and receive signals in the frequency band in accordance
with the determined frequency separation. The frequency band may be
a predefined frequency band.
[0210] The "transmit signal" may be an "uplink signal", from a User
Equipment to the network node, and the "receive signal" may be a
downlink signal, from the network node to the User Equipment.
[0211] In some embodiments, the network node 900 may further be
operable to signal the determined frequency separation to the User
Equipment. The signalling may comprise an identifier identifying
the determined frequency separation. In preferred embodiments, the
network node 900 may be operable to signal the determined frequency
separation to the User Equipment in Radio Resource Control (RRC)
signalling or Layer 1 signalling. The network node 900 may be
operable to signal the determined frequency separation to the User
Equipment as part of scheduling information.
[0212] The network node 900 may be operable to adapt its
transmitter and or receiver based on the determined frequency
separation.
[0213] The network node 900 may further be operable to schedule
transmission of downlink data and or uplink data using the
determined frequency separation.
[0214] The User Equipment may be capable of full-duplex Frequency
Division Duplex (FDD) operation. The User Equipment may be capable
of narrowband operation.
[0215] The physical channels may be Physical Resource Blocks (PRBs)
or Resource Elements (REs).
[0216] The determined frequency separation may be a minimum
transmit-receive carrier frequency separation.
[0217] The skilled person will understand that the User Equipment
800 and or network node 900 may comprise appropriate hardware and
or software such that it is operable to perform the above described
methods. For example, the User Equipment 800 and network node 900
may each comprise a processor and a memory. The skilled person will
also understand that each of the User Equipment 800 and network
node 900 may be considered to include a number of "virtual units"
each configured to, in use, perform a respective step of the above
described methods. For example, each of the User Equipment 800 and
network node 900 may be considered to comprise a determining unit
configured to determine a frequency separation between a frequency
of a transmit signal and a frequency of a receive signal within a
frequency band in a wireless communications network based on at
least one of a power of the transmit signal, a number of physical
channels associated with the transmit signal, and a number of
physical channels associated with the receive signal.
[0218] Embodiments of the present invention have the advantage that
radio resources may be used more efficiently without unacceptably
degrading User Equipment and or network node performance.
* * * * *