U.S. patent application number 12/366025 was filed with the patent office on 2010-08-05 for multiband-operation in wireless communication systems.
This patent application is currently assigned to Infineon Technologies AG. Invention is credited to Maik Bienas, Hyung-Nam Choi.
Application Number | 20100195586 12/366025 |
Document ID | / |
Family ID | 42338884 |
Filed Date | 2010-08-05 |
United States Patent
Application |
20100195586 |
Kind Code |
A1 |
Choi; Hyung-Nam ; et
al. |
August 5, 2010 |
Multiband-operation in wireless communication systems
Abstract
A method and wireless communication network that employs adapted
control channel information to facilitate centralized and
distributed scheduling of network resources for a network with
mobile communication devices of differing bandwidth capabilities
are described. The method includes transmitting control channel
data of a first format over a control channel, wherein the control
channel data of the first format conveys information related to
data transmitted within a first frequency band and transmitting
control channel data of a second format over the control channel,
wherein the control channel data of the second format conveys
information related to data transmitted over one or more frequency
bands, the one or more frequency bands having a combined bandwidth
equal or greater than the first frequency band.
Inventors: |
Choi; Hyung-Nam; (Hamburg,
DE) ; Bienas; Maik; (Braunschweig, DE) |
Correspondence
Address: |
Viering, Jentschura & Partner
3770 Highland Ave., Suite 203
Manhattan Beach
CA
90266
US
|
Assignee: |
Infineon Technologies AG
Neubiberg
DE
|
Family ID: |
42338884 |
Appl. No.: |
12/366025 |
Filed: |
February 5, 2009 |
Current U.S.
Class: |
370/329 ;
370/343 |
Current CPC
Class: |
H04W 72/042
20130101 |
Class at
Publication: |
370/329 ;
370/343 |
International
Class: |
H04W 72/04 20090101
H04W072/04; H04J 1/00 20060101 H04J001/00 |
Claims
1. A method of transmitting data in a communication system, the
method comprising: transmitting control channel data of a first
format over a control channel, wherein the control channel data of
the first format conveys information related to data transmitted
within a first frequency band; and transmitting control channel
data of a second format over the control channel, wherein the
control channel data of the second format conveys information
related to data transmitted over one or more frequency bands, the
one or more frequency bands having a combined bandwidth equal or
greater than the first frequency band.
2. The method of claim 1, wherein transmitting control channel data
of the second format over the control channel comprises
transmitting control channel data of the second format over the
control channel, wherein the one or more frequency bands include
the first frequency band.
3. The method of claim 1, wherein transmitting control channel data
of the first format over the control channel comprises transmitting
control channel data of the first format over the control channel
with a first bandwidth; and wherein transmitting control channel
data of the second format over the control channel comprises
transmitting control channel data of the second format over the
control channel with the first bandwidth.
4. The method of claim 1, wherein transmitting control channel data
of the first format over the control channel comprises transmitting
control channel data of the first format over the control channel
with a first carrier frequency; and wherein transmitting control
channel data of the second format over the control channel
comprises transmitting control channel data of the second format
over the control channel with the first carrier frequency.
5. The method of claim 1, wherein transmitting control channel data
of the first format over the control channel comprises transmitting
control channel data of the first format over the control channel
with a first carrier frequency; and wherein transmitting control
channel data of the second format over the control channel
comprises transmitting control channel data of the second format
over the control channel with a second carrier frequency, the
second carrier frequency being a different frequency than the first
carrier frequency.
6. The method of claim 1, wherein transmitting control channel data
of the first format over the control channel comprises transmitting
control channel data of the first format over the control channel
with a first bandwidth; and wherein transmitting control channel
data of the second format over the control channel comprises
transmitting control channel data of the second format over the
control channel with a second bandwidth, the second bandwidth being
equal or greater than the first bandwidth.
7. The method of claim 1, wherein transmitting control channel data
of the second format comprises transmitting control channel data of
the second format, wherein the second format includes: a carrier
frequency field, the carrier frequency field being indicative of
one or more carrier frequencies to be used in a transmission; and a
physical resource block field, the physical resource block field
being indicative of a number of physical resource blocks allocated
to each one or more carrier frequencies to be used in the
transmission.
8. The method of claim 7, wherein transmitting control channel data
of the second format further comprises transmitting control channel
data of the second format, wherein the second format includes a
mobile communication device bandwidth field, the mobile
communication device bandwidth field being indicative of a radio
frequency transmission and/or reception bandwidth capability of a
mobile communication device.
9. A wireless communication network, the wireless communication
network comprising: a first mobile communication device, the first
mobile communication device operating over a first frequency band;
a second mobile communication device, the second mobile
communication device operating over one or more frequency bands,
the one or more frequency bands having a combined bandwidth equal
or greater than the first frequency band; and a base station,
wherein the base station is configured to: transmit control channel
data of a first format over a control channel, wherein the control
channel data of the first format conveys information related to
data transmitted within the first frequency band; and transmit
control channel data of a second format over the control channel,
wherein the control channel data of the second format conveys
information related to data transmitted over the one or more
frequency bands.
10. The wireless communication network of claim 9, wherein the one
or more frequency bands includes the first frequency band.
11. The wireless communication network of claim 9, wherein the base
station is configured to: transmit control channel data of the
first format over the control channel with a first bandwidth; and
transmit control channel data of the second format over the control
channel with the first bandwidth.
12. The wireless communication network of claim 9, wherein the base
station is configured to: transmit control channel data of the
first format over the control channel with a first carrier
frequency; and transmit control channel data of the second format
over the control channel with the first carrier frequency.
13. The wireless communication network of claim 9, wherein the base
station is configured to: transmit control channel data of the
first format over the control channel with a first bandwidth; and
transmit control channel data of the second format over the control
channel with a second bandwidth, the second bandwidth being equal
or greater than the first bandwidth.
14. The wireless communication network of claim 9, wherein the base
station is configured to: transmit control channel data of the
first format over the control channel with a first carrier
frequency; and transmit control channel data of the second format
over the control channel with a second carrier frequency, the
second carrier frequency being a different frequency than the first
carrier frequency.
15. The wireless communication network of claim 9, wherein the
information related to data transmitted over the one or more
frequency bands includes: a carrier frequency field, the carrier
frequency field being indicative of one or more carrier frequencies
to be used in a transmission; and a physical resource block field,
the physical resource block field being indicative of a number of
physical resource blocks allocated to each one or more carrier
frequencies to be used in the transmission.
16. The wireless communication network of claim 15, wherein the
information related to data transmitted over the one or more
frequency bands further includes a mobile communication device
bandwidth field, the mobile communication device bandwidth field
being indicative of a radio frequency transmission and/or reception
bandwidth capability of the second mobile communication device.
17. The wireless communication network of claim 16, further
comprising a relay node.
18. The wireless communication network of claim 17, wherein the
relay node is configured to: receive control channel data of the
second format; decode control channel data of the second format;
reconfigure control channel data of the second format, wherein the
reconfiguration alters the information related to data transmitted
over the one or more frequency bands; re-encode control channel
data of the second format; and transmit the control channel data of
the second format.
19. A base station for transmitting control channels in a
communication system, the base station configured to: generate
control channel data of a first format, wherein the control channel
data of the first format conveys information related to data to be
transmitted within a first frequency band; generate control channel
data of a second format, wherein the control channel data of the
second format conveys information related to data to be transmitted
over one or more frequency bands, the one or more frequency bands
having a combined bandwidth equal or greater than the first
frequency band; transmit control channel data of the first and
second format over a control channel; and transmit data in
conformance with the control channel data of the first and second
format.
20. A wireless communication device, comprising: a transceiver; a
processor; and a memory unit communicatively connected to the
processor and including: computer code that when executed by the
processor causes the wireless communication device to receive
control channel data; and computer code that when executed by the
processor causes the wireless communication device to interpret the
control channel data, wherein the control channel data includes: a
carrier frequency field, the carrier frequency field being
indicative of one or more carrier frequencies to be used in a
transmission; and a physical resource block field, the physical
resource block field being indicative of a number of physical
resource blocks allocated to each one or more carrier frequencies
to be used in the transmission.
21. The wireless communication device of claim 20, wherein the
control channel data further includes a mobile communication device
bandwidth field, the mobile communication device bandwidth field
being indicative of a radio frequency transmission and/or reception
bandwidth capability of a mobile communication device.
22. The wireless communication device of claim 21, wherein the
wireless communication device is a relay node.
23. The wireless communication device of claim 22, wherein the
relay node is configured to reconfigure control channel data of the
second format.
24. The wireless communication device of claim 20, wherein the
wireless communication device is a mobile communication device.
25. The wireless communication device of claim 20, wherein the
wireless communication device is a base station.
Description
BACKGROUND OF THE INVENTION
[0001] Implementing the next generation of mobile communication
standards will require improving system capacity and spectral
efficiency in order to increase data transmission rate beyond
current levels. For example, Long Term Evolution-Advanced (LTE-A)
is a current topic focused on technologies to further evolve the
Long Term Evolution (LTE) air interface in terms of spectral
efficiency, cell edge throughput, coverage, and latency. In
addition to improving the LTE air interface, another important
consideration is designing a communication system compatible with
both LTE and LTE-A equipment.
[0002] For example, LTE networks employ packet-scheduling, which
dynamically allocates resources to mobile communication device
through time and frequency domain scheduling over a shared physical
control channel. Current LTE networks, however, are unable to
support mobile communication device having higher bandwidth
capabilities than LTE mobile communication device. Thus, a network
capable of supporting mobile communication device with different
bandwidth capabilities is desired.
SUMMARY OF THE INVENTION
[0003] Embodiments of the invention provide methods, wireless
communication networks, and base stations that transmit control
channel data of a first format over a control channel, wherein the
control channel data of the first format conveys information
related to data transmitted within a first frequency band and
transmit control channel data over the control channel of a second
format, wherein the control channel data of the second format
conveys information related to data transmitted over one or more
frequency bands, the one or more frequency bands having a combined
bandwidth equal or greater than the first frequency band.
[0004] Embodiments further provide an apparatus comprising a
transceiver, a processor, and a memory unit communicatively
connected to the processor. The memory unit includes computer code
that when executed by the processor causes the wireless
communication device to receive and interpret control channel data,
wherein the control channel data includes a carrier frequency field
and a physical resource block field.
[0005] These and other features of the invention will be better
understood when taken in view of the following drawings and a
detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] In the drawings, like reference characters generally refer
to the same parts throughout the different views. The drawings are
not necessarily to scale, emphasis instead generally being placed
upon illustrating the principles of the invention. In the following
description, various embodiments of the invention are described
with reference to the following drawings, in which:
[0007] FIG. 1A shows an example frame structure for use with
embodiments of the invention;
[0008] FIG. 1B shows an example physical resource block for use
with embodiments of the invention;
[0009] FIG. 2 shows an example message scheduling chart for use
with embodiments of the invention;
[0010] FIGS. 3A and 3B show, respectively, control channel data
structure in accordance with an embodiment of the invention;
[0011] FIG. 4 shows an architectural overview of an example network
architecture in accordance with an embodiment of the invention;
[0012] FIG. 5 shows an uplink and downlink frequency distribution
in accordance with an embodiment of the invention;
[0013] FIGS. 6A and 6B show, respectively, message sequence charts
for multiband-operation in an LTE-A communication system in
accordance with an embodiment of the invention; and
[0014] FIG. 7 shows a block diagram of an example architecture for
a wireless communication device for use with embodiments of the
invention.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0015] As detailed below, embodiments of the invention provide
adapting control channel information to facilitate centralized and
distributed scheduling of network resources for a network with
mobile communication devices of differing bandwidth
capabilities.
[0016] Example network interfaces for use with embodiments of the
invention, LTE and LTE-A support multiple access methods for uplink
transmissions (from mobile communication device to base station)
and downlink transmissions (from base station to mobile
communication device). For downlink transmission, Orthogonal
Frequency Division Multiple Access (OFDMA) in combination with Time
Division Multiple Access (TDMA) has been selected for Third
Generation Partnership Project (3GPP) Long Term Evolution (LTE) air
interface. OFDMA in combination with TDMA (OFDMA/TDMA) is a
multicarrier, multiple access method in which a mobile
communication device (MCD), such as a mobile telephone, is provided
with a defined number of subcarriers in the frequency spectrum for
a defined transmission time for the purpose of data transmission.
That is, a MCD is assigned network resources in both the frequency
and time domain. Uplink data transmission is based on Single
Carrier Frequency Division Multiple Access (SC-FDMA) in combination
with TDMA.
[0017] LTE and LTE-A also support the following duplexing methods:
TDD, full-duplex FDD and half-duplex FDD. Full-duplex FDD uses two
separate frequency bands for uplink and downlink transmissions such
as media data or control information. Full-duplex FDD allows for
uplink and downlink transmissions to occur simultaneously.
Half-duplex FDD also uses two separate frequency bands for uplink
and downlink transmissions, but transmissions do not overlap in
time. TDD uses the same frequency band for both uplink and downlink
transmissions. Although embodiments are described below in a
full-duplex FDD environment, half-duplex FDD and TDD
implementations are within the scope of the invention.
[0018] FIG. 1A shows an example frame structure for use with
embodiments of the invention. Frame structure 100 is applicable to
full-duplex FDD, half-duplex FDD, OFDMA, and SC-FDMA. Each radio
frame 102 is 10 ms long and consists of 20 slots 104 of length 0.5
ms, numbered from 0 to 19. Subframe 106 is defined as two
consecutive slots. For FDD, 10 subframes are available for downlink
and uplink transmission in each 10 ms interval. Depending on the
slot format, a slot 104 consists of 6 or 7 OFDMA symbols in
downlink transmission and 6 or 7 SC-FDMA symbols in uplink
transmissions. The OFDMA and SC-FDMA symbols contain data as well
as control information assigning network resources to a user.
[0019] FIG. 1B shows an example resource block for use with
embodiments of the invention. Physical resource block 120 is the
smallest unit of allocation assigned by a base station or relay
node for transmitting uplink or downlink data. Downlink physical
resource block 120 includes a matrix of 12 subcarriers 110 by 6 or
7 OFDM symbols 108. A resource element 112 corresponds to one OFDM
symbol and one subcarrier. A typical transmission in an LTE network
will include multiples of 12 subcarriers being simultaneously
transmitted, and thus many resource blocks are also being
transmitted simultaneously.
[0020] In some embodiments, an eNodeB signals the allocation of
physical radio resources for data transmission on a Downlink Shared
Channel (DL-SCH) and an Uplink Shared Channel (UL-SCH), through a
control channel. As used herein, a control channel is a
communication channel that carries at least control information.
Examples of control information include, but are not limited to,
number of allocated resource blocks in the frequency domain,
modulation and coding scheme, transmit power control commands,
Hybrid Automatic Repeat ReQuest process number, and Positive
Acknowledgements/Negative Acknowledgements (HARQ ACK/NAK).
Scheduling and data transport between MCD and a base station or a
relay node in an LTE or LTE-A network occur over physical
channels.
[0021] The Physical Uplink Shared Channel (PUSCH) carries user and
control data on a UL-SCH transport channel. Resources for the PUSCH
are allocated on a sub-frame basis.
[0022] The Physical Uplink Control Channel (PUCCH) is a physical
channel only. That is, no logical or transport channels are mapped
to this channel. It carries the control information such as Hybrid
Automatic Repeat ReQuest Positive Acknowledgements/Negative
Acknowledgements (HARQ ACK/NAK) in response to downlink
transmissions on PDSCH.
[0023] The Physical Downlink Shared Channel (PDSCH) is used mostly
for data and multimedia transport by carrying user and control data
on DL-SCH. It occupies the OFDMA symbols in a subframe not occupied
by Physical Downlink Control Channel.
[0024] The Physical Downlink Control Channel (PDCCH) carries the
control information related to downlink transmissions such as
resource allocation of DL-SCH. It also carries the control
information related to uplink transmissions such as resource
allocation of UL-SCH and Transmit Power Control commands for PUCCH
and PUSCH. Due to the different types of control information to be
transmitted over the PDCCH, the control information has been
grouped into so-called downlink control information (DCI) formats.
For example, a PDCCH with DCI format 0 is used for the scheduling
resources for the PUSCH.
[0025] In some embodiments, the PDCCH is used by an eNodeB to
inform the MCD about the resource allocation of PUSCH and PDSCH.
The MCD can determine whether the resource allocation is intended
for it or not by detecting its implicitly encoded identity. In LTE
a number of PDCCH formats, also referred to as DCI formats, have
been specified. The payload size for each DCI format is variable
and depends mainly on the cell bandwidth.
[0026] Table 1 shows some examples of the DCI formats.
TABLE-US-00001 TABLE 1 DCI formats used for scheduling PUSCH and
PDSCH in FDD Payload size PDCCH formats Purpose (FDD) DCI format 0
PUSCH scheduling Range: 19 . . . 27 bits DCI format 1 Scheduling of
one PDSCH codeword Range: 24 . . . 42 bits DCI format 1A Compact
scheduling of one PDSCH codeword Range: 21 . . . 29 bits DCI format
1B Compact scheduling of one PDSCH codeword with Range: 22 . . . 32
bits precoding information DCI format 1C Very compact scheduling of
one PDSCH codeword Range: 8 . . . 15 bits DCI format 1D Compact
scheduling of one PDSCH codeword with Range: 22 . . . 32 bits
precoding and power offset information DCI format 2 PDSCH
scheduling in closed-loop spatial multiplexing Range: 28 . . . 57
bits mode DCI format 2A PDSCH scheduling in open-loop spatial
multiplexing Range: 25 . . . 53 bits mode
[0027] FIG. 2 shows an example message scheduling chart for use
with embodiments of the invention. Base station 202 transmits over
PDCCH 206 to MCD 204 at Subframe #i indicating that the base
station will transmit data over PDSCH 208 intended for MCD 204.
Once the data has been received from PDSCH 208, a HARQ ACK/NAK is
required to be transmitted by MCD 204 at Subframe #i+4 over the
PUCCH 212. At Subframe #i+1, base station 202 transmits over PDCCH
210 with DCI format 0 to MCD 204 indicating to MCD 204 to adjust
PUSCH 214 transmission scheduled for subframe #i+5.
[0028] The PDCCH formats as currently specified for LTE, however,
cannot be applied to LTE-A as they do not support the resource
allocation of bandwidths larger than 20 MHz. LTE-A requires
resource allocation of bandwidths larger than 20 MHz, for example
up to 100 MHz of bandwidth.
[0029] FIG. 3A shows control channel data structure 300 in
accordance with an embodiment of the invention. Physical resource
allocation information element 302 includes information as to which
carrier frequencies (CFs) are to be used in an uplink or downlink
transmission and the number of physical resource blocks (PRBs)
allocated to each carrier frequency. These two elements enable an
LTE-A network to assign PRBs over multiple carrier frequencies to
an LTE-A MCD. MCD ID element 304 includes an identification number
of a MCD. Payload size element 306 includes transport block size.
Modulation scheme element 308 includes information about which
modulation scheme will be used, e.g., Quadrature Phase-Shift Keying
(QPSK), 16-Quadrature Amplitude Modulation (QAM), 64-QAM. HARQ
information element 310 is implemented to send positive
acknowledgement (ACK) or negative acknowledgement (NAK) signals,
indicating whether a MCD received valid data or not.
[0030] Thus, one embodiment of the invention adapts the PDCCH
structure to facilitate scheduling LTE and LTE-A MCDs. The physical
resource allocation information element of PDCCH formats are
adapted to include information about the carrier frequency assigned
to the LTE-A MCD in uplink or downlink transmission and the number
of resource blocks allocated in each associated frequency band.
[0031] FIG. 3B shows control channel data structure 320 in
accordance with another embodiment of the invention. In some
embodiments, control channel data structure 320 is a PDCCH. Control
channel data structure 320 shares elements 302-310 (i.e., physical
resource allocation information element 302, MCD ID element 304,
payload size element 306, modulation scheme element 308, and HARQ
information element 310) with control channel data structure 300,
but also includes RF transmission (for uplink) and/or RF reception
(for downlink) bandwidth capabilities of an LTE-A MCD at element
312. Element 312 allows an LTE-A network to implement a distributed
scheduling of network resources. That is, both base stations and
relay nodes may allocate network resources to MCDs since a
bandwidth capability of a MCD is known by the network.
[0032] It will be understood that although specific control channel
data structures were recited in describing FIGS. 3A and 3B, FIGS.
3A and 3B are only two possible configurations within the scope of
the invention and that there may be many variations or additions to
this configuration. For example, carrier frequency and physical
resource block information may be contained in separate element
blocks and not in Physical resource allocation information element
302.
[0033] FIG. 4 shows an architectural overview of an example network
architecture in accordance with an embodiment of the invention.
Network 400 includes base station 404, which provides coverage for
cell 402. In some embodiments, base station 404 is an LTE-Advanced
eNodeB. Base station 404 supports direct connections with LTE MCDs
406 and LTE-A MCDs 408. Relay nodes 410 and 412, sometimes referred
to as NodeRs, may be deployed in the cell for providing additional
coverage at cell-edge or coverage holes. Relay nodes 410 and 412
may include a process and a memory unit. LTE MCD 407 and LTE-A MCD
409 communicate with base station 404 via uplink and downlink
transmissions through the intermediate relay nodes 410 and 412.
[0034] The scheduling of uplink and downlink transmissions for LTE
MCDs 406 and 407 may be performed by base station 404 applying an
LTE physical control channel structure, as described in detail
above in Table 1. But for scheduling transmissions for LTE-Advanced
MCDs 408 and 409, current LTE physical control channel structures
cannot be applied and need to be modified. Current LTE physical
control channel structures do not support bandwidths larger than 20
MHz, flexible spectrum usage, or spectrum sharing, all of which an
LTE-A MCD and network may be capable of.
[0035] Moreover, the scheduling of uplink and downlink
transmissions for MCDs 407 and 409 may be performed by relay nodes
410 and 412. For example, relaying or multi-hop communication is
one way to improve the coverage, throughput, and capacity for
existing and future cellular communication systems at low
deployment costs. In a multi-hop embodiment, relay nodes 410 and
412 are deployed in the coverage area of the macro cell 402 for
providing additional coverage at cell edge or coverage holes. In
some embodiments, relay nodes 410 and 412 are adapted to function
like a base station for MCDs 407 and 409 and/or adapted to function
like a MCD for base station 404.
[0036] In one embodiment, base station 404 is an LTE-A eNodeB,
which supports direct connections with LTE MCD 406 and LTE-A MCD
408. Further, connections with LTE MCD 407 and LTE-A MCD 409 are
supported through relay nodes 410 and 412, respectively.
[0037] In some embodiments, LTE MCD 406 and LTE MCD 407 support a
maximum RF transmission/reception bandwidth of 20 MHz and operate
only in 20 MHz uplink and downlink bandwidths.
[0038] In some embodiments, LTE-A MCD 408 and LTE-A MCD 409 support
a maximum RF transmission/reception bandwidth of 60 MHz and operate
in a combined 25 MHz uplink band. In some embodiments, LTE-A MCD
408 and LTE-A MCD 409 operate in an overall 65 MHz downlink band.
In some embodiments, the PDCCHs are transmitted in a frequency band
shared by all MCDs (LTE MCD 406, LTE MCD 407, LTE-A MCD 408, and
LTE-A MCD 409).
[0039] Embodiments within the scope of the present invention
encompass several types of relay nodes, which are categorized
according to the functionality, mobility, and processing
capabilities of the relay node.
[0040] A relay node may be categorized by the protocol layers the
relay affects when relaying a signal, An L1 relay sends an
amplified copy of its received signal and thus only affects the
physical layer of an LTE or LTE-A network. An L2 relay receives and
decodes signals up to an L2 protocol level and transmits a
re-encoded signal. Thus, an L2 relay affects the physical layer and
L2 protocol layers (e.g. MAC and RLC). An L3 relay affects the
physical, L2, and L3 protocol layers and receives and forwards IP
packets.
[0041] A relay node may be also categorized according to the
mobility of the relay node. A Fixed Relay Node is permanently
installed at a fixed location. A Nomadic Relay Node is intended to
function from a location that is fixed for only periods of time. A
Mobile Relay node is designed to function while in motion.
[0042] A relay node may also be classified as an Infrastructure
Relay Node or a UE Relay Node.
[0043] As the above classifications illustrate, incorporating
relaying functionality into the LTE-A system impacts both MCD and
base stations. One issue is the scheduling of physical radio
resources for uplink and downlink transmission. For example, in a
distributed scheduling scheme, the resource allocation is
determined by a relay node in cooperation with a base station. That
is, the relay node is able to change and adapt the resource
allocation in the frequency and/or time domain if required. The
PDCCH. formats as currently specified for LTE cannot support a
distributed scheduling mode in an LTE-A network.
[0044] Thus, in an embodiment of the invention, the PDCCH structure
is adapted to include the RF transmission and reception capability
of LTE-A MCDs. Distributed scheduling between base stations and
relay stations is supported by such a PDCCH structure because a
relay station will be able to change and adapt network resources in
ways that are within the RF transmission and reception capability
of an LTE-A MCD. The physical resource allocation information
element of PDCCH formats are adapted to include information about
the RE transmission/reception bandwidth capability of an
LTE-Advanced MCD, information about the carrier frequency assigned
to the MCD in uplink and downlink transmission, and the number of
resource blocks allocated in the associated frequency band.
[0045] FIG. 5 shows an uplink and downlink frequency distribution
in accordance with an embodiment of the invention. In some
embodiments, an LTE-A radio cell operates in full-duplex FDD mode.
For uplink transmission of an LTE-A MCD, an overall 25 MHz is
allocated with two adjacent frequency bands 502 and 504 with
respective carrier frequencies f1 and f2. For downlink transmission
of an LTE-A MCD, an overall 65 MHz are allocated consisting of four
frequency bands: two adjacent bands 506 and 508 with respective
carrier frequencies f3 and f4, and two non-adjacent bands 510 and
512 with respective carrier frequencies f5 and f6. For uplink
transmission of an LTE MCD, 20 MHz is allocated via frequency band
504 with carrier frequency f2. For downlink transmission of an LTE
MCD, 20 MHz is allocated via frequency band 506 with carrier
frequency f3.
[0046] Although LTE MCDs and LTE-A MCDs operate over different
bandwidths, downlink control information, PDCCH for example, is
transmitted over the frequency band that both types of MCDs use,
frequency band 506. This enables an LTE-A network to be backwards
compatible with LTE MCD.
[0047] It will be understood that although specific frequency
bands, bandwidth, and number of frequency bands were recited in
describing FIG. 5, FIG. 5 is one possible configuration within the
scope of the invention and that there may be many variations or
additions to this configuration. Variations within the scope of the
invention include, but are not limited to, frequency bands larger
or smaller than 5 MHz and 20 MHz, control channel information being
transmitted over multiple carrier frequencies, and a total number
of carrier frequencies being more or fewer than six.
[0048] FIG. 6A shows a message sequence chart for
multiband-operation in an LTE-A communication system in accordance
with an embodiment of the invention. At 608, eNodeB 602 transmits
PDCCH format 1 in a subframe over a 20 MHz frequency band for the
downlink scheduling of LTE MCD 604. PDCCH format 1 allocates a
definite number of resource blocks for the PDSCH within a 20 MHz
frequency band. Upon detection of PDCCH format 1 in the first OFDMA
symbols of the subframe, LTE MCD 604 adjusts the associated PDSCH
reception in the remaining OFDMA symbols of the subframe according
to the received PDCCH format 1 information. Adjustments may include
modulation and coding scheme and HARQ process number.
[0049] At 610, eNodeB 602 transmits LTE-A PDCCH format 1, formatted
in accordance with an embodiment of the invention, over the same 20
MHz frequency band for the downlink scheduling of LTE-A MCD 606.
LTE-A PDCCH format 1 allocates a definite number of resource blocks
for the PDSCH within downlink frequency bands with respective
carrier frequencies f3, f4, and f5, as follows: Carrier frequency
f3: N1 resource blocks; Carrier frequency f4: N2 resource blocks;
Carrier frequency f5: N3 resource blocks.
[0050] Upon detection of LTE-A PDCCH format 1 in the first OFDMA
symbols of the subframe, LTE-A MCD 606 adjusts the associated PDSCH
reception in the remaining OFDMA symbols of the subframe according
to the received PDCCH format 1 information.
[0051] FIG. 6B shows a message sequence chart for
multiband-operation in an LTE-A communication system in accordance
with an embodiment of the invention. The downlink scheduling of LTE
MCD 616 and LTE-A MCD 618 is partly conducted through intermediate
NodeRs 612 and 614. In this embodiment, NodeR2 614 is able to
adapt, in the frequency and/or time domains, resource allocation
transmissions.
[0052] At 620, eNodeB 611 transmits PDCCH format 1 over a 20 MHz
frequency band to NodeR1 612 for the downlink scheduling of LTE MCD
616. PDCCH format 1 allocates a definite number of resource blocks
RBs for the PDSCH within the 20 MHz frequency band. At 624, NodeR1
612 forwards the received PDCCH format 1 to LTE-MCD 616. Upon
detection of PDCCH format 1 in the first OFDMA symbols of the
subframe, LTE MCD 616 adjusts the associated PDSCH reception in the
remaining OFDMA symbols of the subframe according to the received
PDCCH format 1 information.
[0053] At 622, eNodeB 611 transmits LTE-A PDCCH format 4 to NodeR2
614 over the same 20 MHz frequency band for the downlink scheduling
of LTE-A MCD 618. LTE-A PDCCH format 4 is formatted in accordance
with an embodiment of the invention.
[0054] LTE-A PDCCH format 4 allocates a definite number of resource
blocks for the PDSCH within downlink frequency bands with
respective carrier frequencies f3, f4, and f5, as follows: Carrier
frequency f3: N1 resource blocks; Carrier frequency f4: N2 resource
blocks; Carrier frequency f5: N3 resource blocks. In addition, the
RF transmission/reception bandwidth capability of LTE-A MCD 618,
expressed as T MHz, is also included with LTE-A PDCCH format 4.
[0055] NodeR2 614 receives the PDCCH format 4 information and
adapts the resource allocation, due to, for example, temporary bad
channel conditions in frequency bands with respective carrier
frequencies of f3 and f4. Another example for adaption the resource
allocation is to evenly distribute the traffic load over all
available carrier frequencies for reducing signal processing
efforts at the transmitter and receiver. An example adaption by
NodeR2 may then be as follows: Carrier frequency f5: M1 resource
blocks; Carrier frequency f6: M2 resource blocks. At 626, NodeR2
614 transmits the adapted resource allocation on LTE-A PDCCH format
1 to LTE-A MCD 618.
[0056] Upon detection of LTE-A PDCCH format 1 in the first OFDMA
symbols of the subframe, LTE-A MCD 618 adjusts the associated PDSCH
reception in the remaining OFDMA symbols of the subframe according
to the received PDCCH format 1 information.
[0057] It will be understood that although a specific number of
frequency bands were recited in describing FIG. 6, it is only one
possible configuration within the scope of the invention and that
there may be many variations or additions to this configuration.
For example, a relay node may transmit data more or fewer than six
carrier frequencies. Further, a relay node may be able to transmit
both PDCCH format 1 and LTE-A PDCCH format 1.
[0058] FIG. 7 shows a block diagram of an example architecture for
wireless communication device 700 (WCD). As used herein, a wireless
communication device is a device capable of receiving and/or
transmitting signals over a wireless communication network.
Examples include, but are not limited to, base stations, eNodeBs,
relay stations, NodeRs, and mobile phones. WCD 700 includes
processor 702, memory 704, transceiver 706, and network interface
708, connected by bus 710. In some embodiments, memory 704 may
include random access memory 712, such as conventional DRAM, and
non-volatile memory 714, such as conventional flash memory, for
storing the firmware that operates WCD 700, as well as other
parameters and settings that should be retained by WCD 700.
[0059] Transceiver 706 includes antenna 716, which is used for
communication wirelessly with one or more MCDs and/or WCDs. In some
embodiments, for example eNodeBs and NodeRs, network interface 708
connects the WCD 700 to the core network, and may be a conventional
wired network interface, such as a DSL interface, an Ethernet
interface, or a USB interface that connects to an external computer
or network interface device for connection to the core network.
Alternatively, network interface 708 may be a wireless network
interface that communicates with the core network via a wireless
local-area network, a wireless metropolitan area network, or a
wireless wide area network.
[0060] It will be understood that the architecture shown in FIG. 7
is only one possible architecture for WCD 700, and that there may
be many variations or additions to the architecture. For example,
WCD 700 may include I/O devices, such as a display (not shown), a
smart card interface, and a smart card (not shown), to verify that
WCD 700 is authorized for operation, or a variety of indicator
lights or LEDs (not shown), to indicate the current status of WCD
700.
[0061] In summary, an embodiment of the invention provides a method
of transmitting data in a communication system that transmit
control channel data of a first format over a control channel,
wherein the control channel data of the first format conveys
information related to data transmitted within a first frequency
band. The method further transmits control channel data of a second
format over the control channel, wherein the control channel data
of the second format conveys information related to data
transmitted over one or more frequency bands, the one or more
frequency bands having a combined bandwidth equal or greater than
the first frequency band.
[0062] In some embodiments, the one or more frequency bands include
the first frequency band. In some embodiments, the control channel
data of the first format is transmitted over the control channel
with a first bandwidth, and the control channel data of the second
format is transmitted over the control channel with the first
bandwidth.
[0063] In some embodiments, the control channel data of the first
format is transmitted over the control channel with a first carrier
frequency, and the control channel data of the second format is
transmitted over the control channel with the first carrier
frequency.
[0064] In some embodiments, the control channel data of the first
format is transmitted over the control channel with a first
bandwidth, and the control channel data of the second format is
transmitted over the control channel with a second bandwidth the
second bandwidth being equal or greater than the first
bandwidth.
[0065] In some embodiments, the control channel data of the first
format is transmitted over the control channel with a first carrier
frequency, and the control channel data of the second format is
transmitted over the control channel with a second carrier
frequency, the second carrier frequency being a different frequency
than the first carrier frequency.
[0066] In some embodiments, the control channel data of the second
format includes a carrier frequency field, the carrier frequency
field being indicative of one or more carrier frequencies to be
used in a transmission, and a physical resource block field, the
physical resource block field being indicative of a number of
physical resource blocks allocated to each one or more carrier
frequencies to be used in the transmission.
[0067] In some embodiments, the control channel data of the second
format includes a mobile communication device bandwidth field, the
mobile communication device bandwidth field being indicative of a
radio frequency transmission and/or reception bandwidth capability
of a mobile communication device.
[0068] Some embodiments of the invention provide a wireless
communication network, the wireless communication network including
a first mobile communication device, the first mobile communication
device operating over a first frequency band, a second mobile
communication device, the second mobile communication device
operating over one or more frequency bands, the one or more
frequency bands having a combined bandwidth equal or greater than
the first frequency band, a base station. The base station is
configured to transmit control channel data of a first format over
a control channel, wherein the control channel data of the first
format conveys information related to data transmitted within the
first frequency band. The base station is further configured to
transmit control channel data of a second format over the control
channel, wherein the control channel data of the second format
conveys information related to data transmitted over the one or
more frequency bands.
[0069] In some embodiments the one or more frequency bands includes
the first frequency band. In some embodiments, the base station is
further configured to transmit control channel data of the first
format over the control channel with a first bandwidth, and
transmit control channel data of the second format over the control
channel with the first bandwidth.
[0070] In some embodiments the base station is further configured
to transmit control channel data of the first format over the
control channel with a first carrier frequency, and transmit
control channel data of the second format over the control channel
with the first carrier frequency.
[0071] In some embodiments, the base station is further configured
to transmit control channel data of the first format over the
control channel with a first bandwidth, and transmit control
channel data of the second format over the control channel with a
second bandwidth, the second bandwidth being equal or greater than
the first bandwidth.
[0072] In some embodiments the base station is further configured
to transmit control channel data of the first format over the
control channel with a first carrier frequency, and transmit
control channel data of the second format over the control channel
with a second carrier frequency, the second carrier frequency being
a different frequency than the first carrier frequency.
[0073] In some embodiments, the information related to data
transmitted over the one or more frequency bands includes a carrier
frequency field, the carrier frequency field being indicative of
one or more carrier frequencies to be used in a transmission, and a
physical resource block field, the physical resource block field
being indicative of a number of physical resource blocks allocated
to each one or more carrier frequencies to be used in the
transmission.
[0074] In some embodiments, the information related to data
transmitted over the one or more frequency bands further includes a
mobile communication device bandwidth field, the mobile
communication device bandwidth field being indicative of a radio
frequency transmission and/or reception bandwidth capability of the
second mobile communication device.
[0075] In some embodiments, the wireless communication network
further includes a relay node. In some embodiments, the relay node
is configured to receive control channel data of the second format,
decode control channel data of the second format, reconfigure
control channel data of the second format, wherein the
reconfiguration alters the information related to data transmitted
over the one or more frequency bands, re-encode control channel
data of the second format, and transmit the control channel data of
the second format.
[0076] Some embodiments of the invention provide a base station for
transmitting control channels in a communication system. The base
station is configured to generate control channel data of a first
format, wherein the control channel data of the first format
conveys information related to data to be transmitted within a
first frequency band. The base station is further configured to
generate control channel data of a second format, wherein the
control channel data of the second format conveys information
related to data to be transmitted over one or more frequency bands,
the one or more frequency bands having a combined bandwidth equal
or greater than the first frequency band. The base station is
further configured to transmit control channel data of the first
and second format over a control channel and transmit data in
conformance with the control channel data of the first and second
format.
[0077] Some embodiments of the invention provide a wireless
communication device including a transceiver, a processor, and a
memory unit communicatively connected to the processor. The memory
unit includes computer code that when executed by the processor
causes the wireless communication device to receive control channel
data, and computer code that when executed by the processor causes
the wireless communication device to dynamically interpret the
control channel data. The control channel data includes a carrier
frequency field, the carrier frequency field being indicative of
one or more carrier frequencies to be used in a transmission and a
physical resource block field, the physical resource block field
being indicative of a number of physical resource blocks allocated
to each one or more carrier frequencies to be used in the
transmission.
[0078] In some embodiments, the control channel data further
includes a mobile communication device bandwidth field, the mobile
communication device bandwidth field being indicative of a radio
frequency transmission and/or reception bandwidth capability of a
mobile communication device.
[0079] In some embodiments, the wireless communication device is a
relay node. In some embodiments, the relay node is configured to
reconfigure control channel data of the second format. In some
embodiments, the wireless communication device is a mobile
communication device. In some embodiments, the wireless
communication device is a base station.
[0080] While the invention has been particularly shown and
described with reference to specific embodiments, it should be
understood by those skilled in the art that various changes in form
and detail may be made therein without departing from the spirit
and scope of the invention as defined by the appended claims. The
scope of the invention is thus indicated by the appended claims and
all changes which come within the meaning and range of equivalency
of the claims are therefore intended to be embraced.
* * * * *