Note: Descriptions are shown in the official language in which they were submitted.
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METHOD OF CONTROLLING A PLURALITY OF INTERNAL ANTENNAS IN A
MOBILE COMMUNICATION DEVICE
FIELD OF THE DISCLOSURE
The present disclosure relates to the field of antennas for handheld devices
and
more particularly to the optimization of a set of two or more antennas in a
mobile
communications device.
BACKGROUND OF THE DISCLOSURE
Mobile communication devices commonly use internal, rather than external,
antennae for wireless communication. The reception and transmission quality of
an
internal a.ntenna in a mobile communication device can be affected by the
environment
surrounding the device. For example, antenna performance can be negatively
affected
when a user's hand or other object covers or blocks all or part of the
antenna.
Accordingly, an internal antenna is often designed to compromise between two
or more
environments likely to be encountered in use, rather than being optimized for
any one
particular environment.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present disclosure will now be described by way of example
with reference to attached figures, wherein:
FIG. 1 is a block diagram illustrating pertinent components of a mobile
communications device communicating within a wireless communication network
according to one embodiment of the present disclosure;
FIG. 2 is a more detailed diagram of an embodiment of the mobile communication
device of FIG. 1 according to the present disclosure;
FIG. 3 illustrates a mobile communication device incorporating a dual antenna
array and diversity controller according to one embodiment of the present
disclosure;
FIG. 4 illustrates a dual antenna array and dual sensor array according to one
embodiment of the present disclosure;
FIG. 5 illustrates a dual antenna layout according to one embodiment of the
present
disclosure;
FIG. 6A illustrates a mobile communications device being held in a right hand;
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FIG. 6B illustrates a mobile communications device being held in a left hand;
FIG. 7 illustrates a flowchart of a method for selecting an antenna according
to one
embodiment;
FIG. 8A illustrates a flowchart of a method for optimizing antenna usage
according
to one embodiment;
FIG. 8B illustrates a flowchart of a method for optimizing antenna usage
according
to one embodiment; and
FIG. 9 illustrates a flowchart of a method for optimizing antenna selection
according to one embodiment.
DETAILED DESCRIPTION
By using multiple antennas in a diversity arrangement, a mobile communication
device is operable to automatically optimize the best antenna or antenna
combination in
reaction to the device's immediate environment. The individual antenna designs
can be
optimized to provide high antenna system efficiency for a number of likely
device
environments.
According to a first aspect, the present disclosure relates to a method of
operating a
mobile communications device having a housing, a wireless transceiver and a
plurality of
antennas connected to a wireless transceiver. The method comprises the steps
of receiving
a first received signal via a first antenna, receiving a second received
signal via a second
antenna and generating a resultant received signal from the first received
signal and
second received signal. The resultant received signal is generated using a
signal
transformation technique operable to manipulate the first and second received
signals.
According to a second aspect, the present disclosure relates to a method of
operating a mobile communications device having a housing and a plurality of
antennas.
The method comprises the steps of generating, from a raw outgoing signal
(i.e., an
unprocessed signal), first and second transformed outgoing signals for a first
and second
antenna according to a signal transformation technique responsive to at least
a condition
associated with the first and second antennas and transmitting the first and
second
transformed outgoing signals via the first and second antennas.
According to a third aspect, the present disclosure relates to a method of
operating
a mobile communication device having a housing and a plurality of antennas.
The method
comprises the steps of providing the plurality of antennas, determining which
of the
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antennas are optimal for operation of the mobile communication device and
selecting the
optimal antennas for operation of the mobile communication device.
FIG. 1 is a block diagram of a communication system 100 that includes a mobile
communication device 102 that communicates through a wireless communication
network. Mobile communication device 102 preferably includes a visual display
112, a
keyboard 114, and perhaps one or more auxiliary user interfaces (UI) 116, each
of which
is coupled to a controller 106. Controller 106 is also coupled to radio
frequency (RF)
transceiver circuitry 108 and an antenna 110.
Typically, controller 106 is embodied as a central processing unit (CPU) which
runs operating system software in a memory component (not shown). Controller
106 will
normally control overall operation of mobile communication device 102, whereas
signal
processing operations associated with communication functions are typically
performed in
RF transceiver circuitry 108. Controller 106 interfaces with device display
112 to display
received information, stored information, user inputs, and the like. Keyboard
114, which
may be a telephone type keypad or full alphanumeric keyboard, is normally
provided for
entering data for storage in mobile communication device 102, information for
transmission to network, a telephone number to place a telephone call,
commands to be
executed on mobile communication device 102, and possibly other or different
user inputs.
Mobile communication device 102 sends communication signals to and receives
communication signals from the wireless network over a wireless link via
antenna 110.
Although represented by a single icon for simplicity, antenna 110 may
represent any
number of separate antennas. RF transceiver circuitry 108 performs functions
similar to
those of a base station and a base station controller (BSC) (not shown),
including for
example modulation/demodulation and possibly encoding/decoding and
encryption/decryption. It is also contemplated that RF transceiver circuitry
108 may
perform certain functions in addition to those performed by a BSC. It will be
apparent to
those skilled in art that RF transceiver circuitry 108 will be adapted to
particular wireless
network or networks in which mobile communication device 102 is intended to
operate.
Mobile communication device 102 includes a battery interface (IF) 134 for
receiving one or more rechargeable batteries 132. Battery 132 provides
electrical power to
electrical circuitry in mobile communication device 102, and battery IF 134
provides for a
mechanical and electrical connection for battery 132. Battery IF 134 is
coupled to a
regulator 136 which regulates power to the device. When mobile communication
device
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102 is fully operational, an RF transmitter of RF transceiver circuitry 108 is
typically
keyed or turned on only when it is sending to network, and is otherwise turned
off to
conserve resources. Similarly, an RF receiver of RF transceiver circuitry 108
is typically
periodically turned off to conserve power until it is needed to receive
signals or
information (if at all) during designated time periods.
Mobile communication device 102 may, operate using a Subscriber Identity
Module (SIM) 140 which is connected to or inserted in mobile communication
device 102
at a SIM interface (IF) 142. SIM 140 is one type of a conventional "smart
card" used to
identify an end user (or subscriber) of mobile communication device 102 and to
personalize the device, among other things. In one embodiment, without SIM
140, the
mobile communication device terminal is not fully operational for
communication through
the wireless network. By inserting SIM 140 into mobile communication device
102, an
end user can have access to any and all of his/her subscribed services. SIM
140 generally
includes a processor and memory for storing information. Since SIM 140 is
coupled to
SIM IF 142, it is coupled to controller 106 through communication lines 144.
In order to
identify the subscriber, SIM 140 contains some user parameters such as an
International
Mobile Subscriber Identity (IMSI). An advantage of using SIM 140 is that end
users are
not necessarily bound by any single physical mobile communication device. SIM
140
may store additional user information for the mobile communication device as
well,
including datebook (or calendar) information and recent call information.
Mobile communication device 102 may be comprised of a single unit, such as a
data communication device, a multiple-function communication device with data
and
voice communication capabilities, a personal digital assistant (PDA) enabled
for wireless
communication, or a computer incorporating an internal modem. Alternatively,
mobile
communication device 102 may be a multiple-module unit comprising a plurality
of
separate components, including but in no way limited to a computer or other
device
connected to a wireless modem. In particular, for example, in the mobile
communication
device block diagram of FIG. 1, RF transceiver circuitry 108 and antenna 110
may be
implemented as a radio modem unit that may be inserted into a port on a laptop
computer.
In this case, the laptop computer would include display 112, keyboard 114, one
or more
auxiliary UIs 116, and controller 106 embodied as the computer's CPU. It is
also
contemplated that a computer or other equipment not normally capable of
wireless
communication may be adapted to connect to and effectively assume control of
RF
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transceiver circuitry 108 and antenna 110 of a single-unit device such as one
of those
described above. Such a mobile communication device 102 may have a more
particular
implementation as described later in relation to mobile communication device
202 of
FIG. 2.
FIG. 2 is a detailed block diagram of a mobile communication device 202.
Mobile
communication device 202 is preferably a two-way communication device having
at least
voice and advanced data communication capabilities, including the capability
to
communicate with other computer systems. Depending on the functionality
provided by
mobile communication device 202, it may be referred to as a data messaging
device, a
two-way pager, a cellular telephone with data messaging capabilities, a
wireless Internet
appliance, or a data communication device (with or without telephony
capabilities).
Mobile communication device 202 may communicate with any one of a plurality of
fixed
transceiver stations 200 within its geographic coverage area.
Mobile communication device 202 will normally incorporate a communication
subsystem 211, which includes a receiver, a transmitter, and associated
components, such
as one or more (preferably embedded or internal) antenna elements and, local
oscillators
(LOs), and a processing module such as a digital signal processor (DSP) (all
not shown).
Communication subsystem 211 is analogous to RF transceiver circuitry 108 and
antenna
110 shown in FIG. 1. As will be apparent to those skilled in field of
communications,
particular design of communication subsystem 211 depends on the communication
network in wliich mobile communication device 202 is intended to operate.
Network access is associated with a subscriber or user of mobile communication
device 202 and therefore mobile communication device 202 may require a
Subscriber
Identity Module or "SIM" card 262 to be inserted in a SIM IF 264 in order to
operate in
the network. SIM 262 includes those features described in relation to FIG. 1.
Mobile
communication device 202 is a battery-powered device so it also includes a
battery IF 254
for receiving one or more rechargeable batteries 256. Such a battery 256
provides
electrical power to most if not all electrical circuitry in mobile
communication device 202,
and battery IF 254 provides for a mechanical and electrical connection for it.
The battery
IF 254 is coupled to a regulator (not shown) which provides power V+ to all of
the
circuitry.
Mobile communication device 202 includes a microprocessor 238 (which is one
implementation of controller 106 of FIG. 1) which controls overall operation
of mobile
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communication device 202. Communication functions, including at least data and
voice
communications, are performed through communication subsystem 211.
Microprocessor
238 also interacts with additional device subsystems such as a display 222, a
flash memory
224, a random access memory (RAM) 226, auxiliary input/output (I/O) subsystems
228, a
serial port 230, a keyboard 232, a speaker 234, a microphone 236, a short-
range
communications subsystem 240, and any other device subsystems generally
designated at
242. Some of the subsystems shown in FIG. 2 perform communication-related
functions,
whereas other subsystems may provide "resident" or on-device functions.
Notably, some
subsystems, such as keyboard 232 and display 222, for example, may be used for
both
communication-related functions, such as entering a text message for
transmission over a
communication network, and device-resident functions such as a calculator or
task list.
Operating system software used by microprocessor 238 is preferably stored in a
persistent
store such as flash memory 224, which may alternatively be a read-only memory
(ROM)
or similar storage element (not shown). Those skilled in the art will
appreciate that the
operating system, specific device applications, or parts thereof, may be
temporarily loaded
into a volatile store such as RAM 226.
Microprocessor 238, in addition to its operating system functions, preferably
enables execution of software applications on mobile communication device 202.
A
predetermined set of applications which control basic device operations,
including at least
data and voice communication applications, will normally be installed on
mobile
communication device 202 during its manufacture. A preferred application that
may be
loaded onto mobile coinmunication device 202 may be a personal information
manager
(PIM) application having the ability to organize and manage data items
relating to the user
such as, but not limited to, instant messaging (IM), e-mail, calendar events,
voice mails,
appointments, and task items. Naturally, one or more memory stores are
available on
mobile communication device 202 and SIM 262 to facilitate storage of PIM data
items and
other information.
The PIM application preferably has the ability to send and receive data items
via
the wireless network. In a preferred embodiment, PIM data items are seamlessly
integrated, synchronized, and updated via the wireless network, with the
mobile
communication device user's corresponding data items stored and/or associated
with a
host computer system thereby creating a mirrored host computer on mobile
communication device 202 with respect to such items. This is especially
advantageous
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where the host computer system is the mobile communication device user's
office
computer system. Additional applications may also be loaded onto mobile
communication
device 202 through a network of fixed transceiver stations 200, an auxiliary
I/O subsystem
228, serial port 230, short-range communications subsystem 240, or any other
suitable
subsystem 242, and installed by a user in RAM 226 or preferably a non-volatile
store (not
shown) for execution by microprocessor 238. Such flexibility in application
installation
increases the functionality of mobile communication device 202 and may provide
enhanced on-device functions, communication-related functions, or both. For
example,
secure communication applications may enable electronic commerce functions and
other
such financial transactions to be performed using mobile communication device
202.
In a data communication mode, a received signal such as a text message, an e-
mail
message, or web page download will be processed by communication subsystem 211
and
input to microprocessor 238. Microprocessor 238 will preferably further
process the
signal for output to display 222, to auxiliary I/O device 228 or both as
described further
herein below with reference to Figures 3-7. A user of mobile communication
device 202
may also compose data items, such as e-mail messages, for example, using
keyboard 232
in conjunction with display 222 and possibly auxiliary I/O device 228.
Keyboard 232 is
preferably a complete alphanumeric keyboard and/or telephone-type keypad.
These
composed items may be transmitted over a communication network through
communication subsystem 211.
For voice communications, the overall operation of mobile communication device
202 is substantially similar, except that the received signals would be output
to speaker
234 and signals for transmission would be generated by microphone 236.
Alternative
voice or audio I/O subsystems, such as a voice message recording subsystem,
may also be
implemented on mobile communication device 202. Although voice or audio signal
output is preferably accomplished primarily through speaker 234, display 222
may also be
used to provide an indication of the identity of a calling party, duration of
a voice call, or
other voice call related infomlation, as some examples.
Serial port 230 in FIG. 2 is normally implemented in a personal digital
assistant
(PDA)-type communication device for which synchronization with a user's
desktop
computer is a desirable, albeit optional, component. Serial port 230 enables a
user to set
preferences through an external device or software application and extends the
capabilities
of mobile communication device 202 by providing for information or software
downloads
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to mobile communication device 202 other than through a wireless communication
network. The alternate download path may, for example, be used to load an
encryption
key onto mobile communication device 202 through a direct and thus reliable
and trusted
connection to thereby provide secure device communication.
Short-range communications subsystem 240 of FIG. 2 is an additional optional
component which provides for communication between mobile communication device
202
and different systems or devices, which need not necessarily be similar
devices. For
example, subsystem 240 may include an infrared device and associated circuits
and
components, or a BluetoothTM communication module to provide for communication
with
similarly-enabled systems and devices. BluetoothTM is a registered trademark
of
Bluetooth SIG, Inc.
In accordance with an embodiment of the disclosure, mobile communication
device 202 is a multi-tasking handheld wireless communications device
configured for
sending and receiving data items and for making and receiving voice calls. To
provide a
user-friendly environment to control the operation of mobile communication
device 202,
an operating system resident on communication device 202 (not shown) provides
a GUI
having a main screen and a plurality of sub-screens navigable from the main
screen.
FIG. 3 depicts an embodiment of a mobile communications device 302 in
accordance with the present disclosure. The mobile communications device 302
illustratively includes a housing 304, and a wireless transceiver 306 disposed
within the
housing 304. The mobile communications device 302 also illustratively includes
an
antenna assembly 308 for cooperating with the wireless transceiver 306 to
communicate
over the wireless network described above. More particularly, the mobile
communications
device 302 may be a PDA-type device in which the wireless transceiver 306 and
antenna
assembly 308 cooperate to communicate various types of data, such as voice
data, video
data, text (e.g., email) data, Internet data, etc. over the wireless network.
More
specifically, the antenna assembly 308 may be used for placing telephone
calls, in which
case the mobile communication device 302 may generally take the form or shape
of a
typical cellular telephone or a cellular-enabled PDA device, for example.
The antenna assembly 308 includes a plurality of antennas, preferably a pair
of an
antennas 310, 312 as illustrated. The pair of antennas 310, 312 are positioned
in side-by-
side relation preferably in the upper portion of the housing 304. A diversity
controller 314
is connected to the wireless transceiver 306 to preferentially operate with
the pair of
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antennas 310, 312 to optimize reception based upon the environment within
which the
mobile communication device 302 is disposed.
The housing 304 preferably has opposing parallel front and back surfaces and
the
plurality of antennas 310, 312 are arranged in side-by-side relation extending
in a plane
parallel to the front and back surfaces. A display, a user input device and
other
components (not shown) may be carried by the housing 304 as discussed above.
The
transceiver 306 and the plurality of antennas 310, 312 are operable to
communicate with
fixed transceiver stations 200 as part of a cellular wireless network or a LAN
wireless
network. In certain embodiments, the wireless LAN may operate in accordance
with
various wireless LAN standards, such as IEEE 802.11/802.1 l.b, BluetoothTM or
ZigbeeTM
for example, as will also be appreciated by those skilled in the art.
As discussed above, a mobile communication device will commonly use internal,
rather than external, antennas for wireless communication. The reception and
transmission quality of an internal antenna in a mobile communications device
can, and
generally will, be affected by the environment surrounding the device. For
example,
antenna performance can be negatively affected when a user's hand or other
object covers
or blocks all or part of the antenna. Accordingly, an internal antenna is
often designed to
compromise between two or more environments likely to be encountered in use,
rather
then being optimized for any one particular environment.
FIG. 4 shows an embodiment of a mobile communication device 402 having a
housing 404 in which two sensors 406, 408 are disposed. Each of sensors 406,
408 is
associated with a corresponding antenna 410, 412. The antennas 410, 412 may
have the
same or a different form. In one embodiment, the two sensors 406, 408 may be
used to
determine whether one or both antennas are covered up by a user. In certain
embodiments, one of antennas 410, 412 may be selected as a primary antenna.
Turning additionally to FIG. 5, further details of an embodiment of the
antenna
assembly 308 of FIG. 3 will be described. The antenna assembly 308
illustratively
includes the first antenna 310 coupled to the transceiver 306 at a feed point
500 and
having a first shape. The antenna assembly 308 also illustratively includes
the second
antenna 312 coupled to the wireless transceiver 306 at a feed point 502. It
will be noted
that second antenna 312 has a shape different from the shape of first antenna
310.
The polarizations of the first and second antennas 310, 312 may be orthogonal
to
one another in order to provide maximum polarization diversity, as will be
appreciated by
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those skilled in the art: Of course, other arrangements may be possible in
other
embodiments.
The first and second antennas 310, 312 may advantageously be implemented as
planar, printed radiative elements on a circuit board 504. The circuit board
may be
mounted on the back side of the mobile communication device 302 (i.e., the
side pointing
away from the user when holding the device to place a telephone call) or at
the top of the
mobile communication device (i.e., adjacent the end of the device with the ear
speaker).
First and second antennas 310, 312 are shown with hatching to provide greater
clarity of
illustration.
First antenna 310 illustratively includes a feed branch 506 including the
first feed
point 500, a second feed point 508 which is connected to ground, and a feed
section 510
connected between the first and second feed points 500, 508. First antenna 310
further
illustratively includes a loop branch 512 having a first end 514 coupled to
the feed section
510 adjacent the first feed point 500. A second end 516 of the loop branch 512
is spaced
apart from the feed section 510 by a gap 518, and the second end is adjacent
the second
feed point 508. A loop-back section 520 extends between the first and second
ends 514,
516. More specifically, the loop-back section 520 generally loops in a
clockwise direction
from the first end 514 to the second end 516, as shown. First antenna 310 thus
generally
defines a dual feed point, open loop configuration. This configuration
advantageously
provides increased space savings (i.e., reduced antenna footprint), as will be
appreciated
by those skilled in the art.
The second antenna 312 also illustratively includes a feed branch defined by
the
feed point 502 and a feed section 522. Further, a loop branch having a first
end 524
coupled to the feed section 522, a second end 526 adjacent the feed branch and
separated
therefrom by a gap 528, and a loop-back section 530 extending between the
first and
second ends. The loop-back section 530 illustratively includes an arcuate
portion 532. The
second antenna 312 thus defines a single feed point, open loop element
configuration.
Again, this provides space savings, and, thus, reduced antenna footprint.
As will be appreciated by those skilled in the art, various design parameters
(e.g.,
widths, lengths, loop shapes, notches, etc.) may be altered in the first and
second antennas
310, 312 to provide different signal characteristics. By way of example, the
overall
dimensions of the first and second antennas 310, 312 may be 2 to 3 cm high by
2 to 3 cm
wide for each element, although other dimensions may also be used. The
antennas 310,
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312 preferably operate over a number of frequency bands and ranges, a wireless
frequency
range of about 2.4 to 2.5 GHz, for example, although other frequencies are
also possible.
Moreover, the coupling between the first and second antennas 310, 312 may also
be
adjusted to provide desired performance characteristics. By way of example, a
preferred
coupling distance or gap between the first and second antennas 310, 312 may be
in a range
of about 3 to 7 mm, although other gap distances may also be used as
appropriate for
different embodiments.
Because the first and second antennas 310, 312 have different shapes, they
will
also have different gain patterns, and thus advantageously provide pattern
diversity, as will
be appreciated by those skilled in the art. Moreover, the first and second
antennas 310,
312 are preferably tuned to have substantially equal main lobe gain for
enhanced
performance. Of course, it will be appreciated that other antenna element
shapes or types
may be used in addition to those noted above. Electromagnetic shielding may be
placed
over one or both sides of the circuit board 504 as necessary in certain
applications, as will
also be appreciated by those skilled in the art.
One aspect of the present disclosure may include controlling the wireless
transceiver 306 to preferentially operate with the pair of antennas 310, 312
based upon a
relative position of the housing 304 with respect to a hand of a human user.
Again,
controlling the wireless transceiver 306 may include preferentially weighting
transmit
signals or preferentially switching one antenna on and one antenna off for
transmit signals.
Additional aspects will be appreciated by those skilled in the art from the
foregoing
description.
Turning now to FIGS. 6A and 6B, an embodiment of the pair of antennas 310, 312
and associated diversity controller 314 of mobile communication device 302
will be
described with respect to ergonomic aspects of device handling by users.
Firstly, by using
multiple antennas 310, 312, mobile communication device 302 can select the
best antenna,
or weighted or otherwise processed combination, based upon the environment
surrounding
the device. The environment generally includes, but is not limited to,
portions of the
device user's body, including the user's hands. Accordingly, the FIGS. 6A and
6B depict
situations in which the antenna reception is affected by a user's hand 600
covering a
portion of the housing 304, though similar situations arise when, for example,
a portion of
the housing 304 is covered by a user's head or clothing.
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The antennas 310, 312 are designed to provide an overall high antenna system
efficiency for the common user holding positions. The figures respectively
illustrate a
user holding the device 302 in a right hand 600 and a left hand 602. As can be
seen, a
user's hand 600, 602 may be directly adjacent one of antennas 310, 312,
thereby affecting
the performance of one or both of antennas 310, 312. Accordingly, the
associated diversity
controller 314 will preferentially operate the pair of antennas 310, 312 to
provide
optimized signal transmission/reception. In FIG. 6A, the user's right hand 600
is partially
blocking antenna 312, while leaving antenna 310 unobstructed. In FIG. 6B, the
user's left
hand 602 is partially blocking antenna 310, while leaving antenna 312
unobstructed. In
either case, either of the unobstructed antennas may nevertheless have their
signals
affected by the proximity of the user's hand. Conversely, either of the
partially obstructed
antennas may nevertheless retain the capability to transmit or receive some
level of signal,
though reduced in strength or quality. In certain embodiments, diversity
controller 314
may employ one or more partially obstructed antennas. In certain embodiments,
diversity
controller 314 may perform some form of signal transformation or conditioning
in order to
compensate for the effect of the obstruction or other interference.
The diversity controller 314 (shown in FIG. 3) processes incoming and outgoing
signals in order to optimize the use of antennas 310, 312. Diversity
controller 314 may,
for example, preferentially weight transmit signals, or switch at least one
antenna on and
at least one antenna off, for example, based upon received signal strength.
Other
processing methods will be known to those of skill in the art. The plurality
of antennas
310, 312 may be operable on a common frequency, have different polarizations,
have
different conductive patterns or have different frequencies for transmit and
receive,
depending on the particular application.
FIG. 7 shows an embodiment of a method for selecting between multiple
antennas.
Although the flowchart of FIG. 7 relates to a dual antenna arrangement, it is
to be
understood that a similar method may be employed for a device having more than
two
antennas. Process flow begins at block 702. In decision block 704, the
diversity
controller inquires whether antenna 1 is obstructed. This may be determined,
for example,
by a sensor corresponding to antenna 1, or by the existence of very weak
signal reception
at antenna 1. If antenna 1 is not obstructed, the diversity controller selects
antenna 1 for
communication (block 706). If antenna 1 is obstructed, the diversity
controller selects
antenna 2 for communication (block 708).
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FIG. 8A depicts one embodiment of a method for optimizing antenna usage in a
receive mode. In block 800, diversity controller 314 receives a first received
signal via a
first antenna. In block 802, diversity controller 314 receives a second
received signal via a
second antenna. In block 804, diversity controller 314 generates a resultant
received
signal from the first received signal and second received signal using a
signal
transformation technique operable to manipulate the first and second received
signals. In
certain embodiments, the signal transformation technique may constitute
amplification of
one or both of the received signals. In certain embodiments, the signal
transformation
technique may constitute attenuation of one or both of the received signals.
Other signal
processing techniques, such as filtering and phase shifting techniques, may be
employed in
particular applications. In certain embodiments, the signal transformation
technique is
selected or optimized based on the characteristics of one or more of the
received signals.
FIG. 8B depicts one embodiment of a method for optimizing antenna usage in a
transmit mode. In block 806, the diversity controller 314 generates, from a
raw outgoing
signal, first and second transfornied outgoing signals for a first and second
antenna. The
transformed outgoing signals are generated according to a signal
transformation technique
responsive to at least one condition associated with the first and second
antennas. The
condition may relate, for example, to the relative strength of received
signals or the state
of certain sensors. Signal transformation may include one or more of a number
of signal
processing techniques, such as amplification, attenuation, filtering and phase
shifting
techniques, as examples. In block 808, the diversity controller transmits the
first and
second transformed outgoing signals via the first and second antennas.
FIG. 9 depicts one embodiment of a method for optimizing antenna selection in
either a receive or a transmit mode. In block 900, a plurality of antennas are
provided. In
block 902, diversity controller 314 determines which antennas are optimal for
operation of
the mobile communication device. As above, determination may be based on, for
example, the relative strength of received signals or the state of certain
sensors. In block
904, the optimal antennas are selected for operation of the mobile
communication device.
According to one embodiment, a method of operating a mobile communications
device may include both receiving and transmitting signals via two or more
antennas.
Initially, signals are received via each of the antennas and analyzed. Based
on the
analysis, a received signal transformation algorithm and outgoing signal
transformation
algorithm is selected or generated for each of the antennas. A resultant
received signal can
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CA 02584375 2007-04-17
WO 2006/042399 PCT/CA2005/001586
then be generated from the received signals using the received signal
transformation
algorithms, and a set of transformed outgoing signals can be generated from a
raw
outgoing signal according to the outgoing signal transformation algorithms.
The
transformed outgoing signals can then be transmitted via the antennas
associated
therewith.
Although the foregoing disclosure has been described in relation to certain
particular applications and embodiments, those of skill in the art will
recognize that other
variations are contemplated and within the spirit of the present disclosure.
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