U.S. patent application number 12/276232 was filed with the patent office on 2009-05-28 for directional antenna configuration for tdd repeater.
This patent application is currently assigned to QUALCOMM Incorporated. Invention is credited to Kenneth M. Gainey, James C. Otto, James A. Proctor, JR., Christopher A. Snyder.
Application Number | 20090135745 12/276232 |
Document ID | / |
Family ID | 38067877 |
Filed Date | 2009-05-28 |
United States Patent
Application |
20090135745 |
Kind Code |
A1 |
Gainey; Kenneth M. ; et
al. |
May 28, 2009 |
DIRECTIONAL ANTENNA CONFIGURATION FOR TDD REPEATER
Abstract
A wireless communication node, such as a repeater, including a
frequency translating repeater, a physical layer (PHY) repeater,
time divisional duplex repeater (TDD) and the like, is configured
with a pair of directional patch antennae and an omni-directional
antenna. The patch antennae can be selected depending on the
orientation of the repeater package to communicate with a station
such as an access point or a base station. The omni-directional
antenna can be directed toward another station such as a client.
The patch antennae and the omni-directional antenna can be
orthogonally polarized to increase isolation and reduce
electromagnetic coupling. Multiple antennae can be used in
multiple-input-multiple-output (MIMO) configurations.
Inventors: |
Gainey; Kenneth M.;
(Satellite Beach, FL) ; Proctor, JR.; James A.;
(Melbourne Beach, FL) ; Snyder; Christopher A.;
(Melbourne, FL) ; Otto; James C.; (West Melbourne,
FL) |
Correspondence
Address: |
POSZ LAW GROUP, PLC
12040 SOUTH LAKES DRIVE, SUITE 101
RESTON
VA
20191
US
|
Assignee: |
QUALCOMM Incorporated
San Diego
CA
|
Family ID: |
38067877 |
Appl. No.: |
12/276232 |
Filed: |
November 21, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11602455 |
Nov 21, 2006 |
7463200 |
|
|
12276232 |
|
|
|
|
60738579 |
Nov 22, 2005 |
|
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Current U.S.
Class: |
370/279 |
Current CPC
Class: |
H04W 88/085 20130101;
H01Q 1/38 20130101; H01Q 7/00 20130101; H04B 7/1555 20130101; H01Q
19/10 20130101 |
Class at
Publication: |
370/279 |
International
Class: |
H04B 7/14 20060101
H04B007/14 |
Claims
1. A wireless communication apparatus comprising: a receiver
portion; a transmitter portion; a substantially omni-directional
antenna coupled to the receiver portion and the transmitter
portion, wherein the wireless apparatus is configured to use the
transmitter portion to transmit wireless signals from the
omni-directional antenna during a first interval; and a pair of
directional antenna coupled to the receiver portion and the
transmitter portion, the wireless apparatus configured to receive
wireless signals using the pair of directional antenna during at
least a portion of the first interval.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation of U.S. patent
application Ser. No. 11/602,455 filed on Nov. 21, 2006 which claims
priority to U.S. Provisional Patent Application No. 60/738,579,
filed Nov. 22, 2005 entitled "DIRECTIONAL ANTENNA CONFIGURATION FOR
TDD REPEATER," the contents of each of which are incorporated
herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to wireless
communication and more specifically to an antenna configuration
associated with a wireless Time Division Duplex (TDD) repeater, the
antenna configuration made up of closely packaged antennas having
orthogonal polarization and isolation to reduce electromagnetic
coupling and to provide high directivity.
BACKGROUND OF THE INVENTION
[0003] In a wireless communication node, such as a TDD repeater
designed to operate with a TDD based wireless system capable of
simultaneous transmission and reception of TDD packets, the
orientation of the antenna units is crucial in establishing
non-interfering operation as it is critical that the receiver is
not desensitized by the transmitted signals. Further, enclosing
antenna modules and repeater circuitry within the same package is
desirable for convenience, manufacturing cost reduction and the
like, but such packaging can give rise to interference
problems.
[0004] In a full duplex repeater package for use in a TDD system,
one antenna or set of antennae may operate with, for example, a
base station, and another antenna operates with a subscriber. Since
the frequency for the TDD repeater may be the same, or at least may
be very close in frequency for both sides of the repeater,
isolation becomes important particularly when simultaneous
transmission and reception on both sides of the repeater are
performed. Further, since the repeater unit houses all circuitry
within a single package, it is desirable to closely position the
antennae with minimal antenna-to-antenna interaction while
maintaining acceptable gain and in many cases acceptable
directivity. Directivity in antennae is desirable for use in links
where the direction of the signal arrival will not vary, or at
least will vary infrequently such as in a link from a repeater to a
base station or Access Point (AP). Difficulties arise however, in
that the use of antennae with high directivity requires that
directional alignment with the base station or AP be performed,
typically by trial-and-error manual alignment.
[0005] For ease of manufacture, an exemplary repeater should be
configured such that it can be easily produced in high volume
manufacturing operations using low cost packaging. The exemplary
repeater should be simple to set up to facilitate easy customer
operation. Additional problems arise however when packaging
repeater antennae and circuitry in close proximity. First, it
becomes difficult to achieve high isolation between antennae due
solely to the close physical proximity even where directional
antennae are used. Isolation becomes even more difficult where
antennas having omni directional antenna patterns are used and
where the proximity of the repeater to structures such as walls,
furniture or other objects cannot be anticipated, and thus cannot
be compensated for in advance due to unknown such as the final
placement of the repeater module.
[0006] Simply put, as the antennae are placed closer together, the
more likely the antennae will couple energy into each other, which
reduces the isolation between the sides of the repeater.
Maintaining an omni or semi-omni directional antenna pattern
becomes difficult since overlapping radiation patterns of antennae
which are placed close to each other tend to generate interference
effects. Energy from the antennae can further be electrically
coupled through circuit elements such as through a shared ground
plane especially in configurations where multiple antennas are
integrated and the ground plane is small. While the use of
direction antenna can benefit the repeater in terms of increased
range and reduced wireless signal variation due to Raleigh fading
effects, directional antennas are not typically used for indoor
applications, due to the requirement for directional alignment,
which is beyond the capability or desire of the average user.
[0007] Some improvements can be obtained through cancellation or
similar techniques where a version of a signal transmitted on one
side of the repeater is used to remove the same signal if it
appears on the other side of the repeater. Such cancellation
however can be expensive in that additional circuitry is required,
and can be computationally expensive in that such cancellation can
result in the introduction of a delay factor in the repeater or
alternatively can require the use of more expensive and faster
processors to perform the cancellation function.
SUMMARY OF THE INVENTION
[0008] The present invention overcomes the above problems by
providing an exemplary antenna array configuration in which two
closely spaced patch antennae are combined with a dipole antenna
such that one of the patch antennae can be selected depending on
the orientation of the repeater package to communicate with a base
station, AP, or the like, and the dipole antenna can be directed
generally toward a client device such as a subscriber device, a
user device, a wireless communication node, or the like. The patch
antennae and the dipole antenna are orthogonally polarized to
increase isolation and reduce electromagnetic coupling between the
patch and dipole antennae. The antennae can be fed in a balanced
configuration to reduce common mode currents. The use of multiple
switched directional antennae allows for minimal user interaction
during initial configuration and the repeater electronics may be
utilized for automatic selection of the best directional antenna
for use during initial configuration, and also periodically during
operation.
[0009] The exemplary antenna configuration can include a monopole,
a dipole, or another substantially omni-directional antenna element
facing a client side of the repeater and two patch antennae facing
the base station side of the repeater. The patch antennae are in
parallel relation to each other and a substrate such as a ground
plane located therebetween. The client side element can be arranged
on the ground plane and, as noted, can be a monopole antenna, a
dipole antenna, or the like. Either of the patch antennae can
operate depending on which antenna has the best signal
characteristics for communicating with a base station antenna. An
isolation fence can be used between the patch antennae and the
client side antenna arranged in perpendicular relation to the
planes of the patch antennae and the main ground plane/circuit
substrate.
[0010] It will be appreciated that placement of the repeater unit
will have a large impact on determining the signal quality both
toward the base station and between the repeater client or clients.
Therefore, repeater performance can be analyzed and a user could be
directed to reposition the repeater unit for optimum signal
performance. In accordance with the present invention, the use of
two or more switchable patch antennae can address the placement
issue to an extent by allowing the system to select which of the
patch antenna will provide the best reception toward the base
station.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The accompanying figures, where like reference numerals
refer to identical or functionally similar elements throughout the
separate views and which together with the detailed description
below are incorporated in and form part of the specification, serve
to further illustrate various embodiments and to explain various
principles and advantages in accordance with the present
invention
[0012] FIG. 1 is a diagram illustrating dipole array configurations
in accordance with various exemplary embodiments.
[0013] FIG. 2 is a graph illustrating the radiation patterns of a
dipole portion of an exemplary dipole array configuration with and
without an isolation fence in accordance with various exemplary
embodiments.
[0014] FIG. 3 is a graph illustrating the radiation patterns of a
patch portion of an exemplary dipole array configuration with and
without an isolation fence in accordance with various exemplary
embodiments.
[0015] FIG. 4 is a graph illustrating the combined radiation
patterns of a dipole portion and patch portions of an exemplary
dipole array configuration with an isolation fence in accordance
with various exemplary embodiments.
[0016] FIG. 5 is a graph illustrating isolation vs. frequency
between dipole and patch portions of a dipole array configuration
with an isolation fence in accordance with various exemplary
embodiments.
[0017] FIG. 6 is a graph illustrating the voltage standing wave
ratio (VSWR) for a dipole portion and a patch portion of a dipole
array configuration with and without an isolation fence in
accordance with various exemplary embodiments.
[0018] FIG. 7 is a diagram illustrating monopole array
configurations in accordance with various exemplary
embodiments.
[0019] FIG. 8 is a graph illustrating the radiation patterns of a
monopole portion of an exemplary monopole array configuration with
and without an isolation fence in accordance with various exemplary
embodiments.
[0020] FIG. 9 is a graph illustrating the radiation patterns of a
patch portion of an exemplary monopole array configuration with and
without an isolation fence in accordance with various exemplary
embodiments.
[0021] FIG. 10 is a graph illustrating isolation vs. frequency
between monopole and patch portions of a monopole array
configuration with an isolation fence in accordance with various
exemplary embodiments.
[0022] FIG. 11 is a graph illustrating the voltage standing wave
ratio (VSWR) for a monopole portion and a patch portion of a
monopole array configuration with and without an isolation fence in
accordance with various exemplary embodiments.
[0023] FIG. 12A is a diagram illustrating an enclosure for an
antennae array configuration in accordance with various exemplary
embodiments including a dipole array configuration.
[0024] FIG. 12B is a diagram illustrating an internal view of the
enclosure of 12A in accordance with various exemplary
embodiments.
[0025] FIG. 13A is a diagram illustrating an alternative enclosure
for an antennae array configuration in accordance with various
exemplary embodiments.
[0026] FIG. 13B is a diagram illustrating an internal view of the
enclosure of 13A in accordance with various exemplary
embodiments.
[0027] FIG. 14 is a diagram illustrating switching unit for
switching between directional antennae in accordance with various
exemplary embodiments.
[0028] FIG. 15 is a diagram illustrating a repeater in a system
with a client and an access point in accordance with various
exemplary embodiments.
DETAILED DESCRIPTION OF THE INVENTION
[0029] A directional antenna configuration is disclosed and
described herein for a wireless communication node such as a TDD
repeater. The exemplary antenna configuration can include a
monopole, a dipole, or an alternative omni-directional or quasi
omni-directional antenna element or configuration such as an "F"
shaped antenna or the like, facing a client side of the repeater
and two patch antennae facing the base station side of the
repeater. The patch antennae are arranged in parallel relation to
each other and in relation to a ground plane arranged therebetween
and extending beyond the patch antennae on one side, such as the
client side. The client side element can be arranged on the ground
plane and, as noted, can be a monopole antenna, a dipole antenna,
or the like. The patch antennae are both orthogonally polarized
with respect to the client side antenna and are preferably
vertically polarized, while the client side antenna is horizontally
polarized. Either one of the two patch antenna can be switched into
operation depending on which antenna has the best signal
characteristics for communicating with a base station antenna.
[0030] Circuitry for the repeater can further be arranged on the
ground plane between the patch antennae and thus can be configured
for maximum noise rejection. For example, to reduce generalized
coupling through the ground plane or repeater circuit board
substrate, the antennae can be driven in a balanced fashion such
that any portion of a signal coupling into the feed structure of
another antenna will be common mode coupling for maximum
cancellation. To further improve isolation and increase link
efficiency, an isolation fence can be used between the patch
antennae and the client side antenna. The isolation fence consists
of, for example, a second ground plane or planar conductor portion
arranged in perpendicular relation to the planes of the patch
antennae and the main ground plane/circuit substrate.
[0031] It will be appreciated that placement of the repeater unit
will have a large impact on determining the signal quality both
toward the base station and toward the repeater client or clients.
In some embodiments, a sounding signal can be used to analyze
repeater performance. Based on the analysis, a user could be
directed to reposition the repeater unit for optimum signal
performance. In accordance with the present invention, the use of
two switchable patch antennae can address the placement issue to an
extent by allowing the system to select which of the patch antenna
will provide the best reception toward the base station.
[0032] As noted above, the exemplary repeater can be configured as
a dipole patch array 100 as shown in FIG. 1. In arrangements 110
and 120, a pair of parallel patch antennae 114 and 115 can be
arranged on either side of a ground plane 113, which can also be
used as the circuit board for the repeater circuitry. Each of the
patch antennae 114 and 115 are arranged in parallel with the ground
plane 113 and can be printed on a printed circuit board (PCB),
wiring board or the like, or can be constructed of a stamped metal
portion embedded in a plastic housing. A planar portion of the PCB
associated with the ground plane 113 can contain an antenna, such
as a dipole antenna 111 configured, for example, as an embedded
trace thereon and directed toward the client side of the repeater.
It will be appreciated that the orientation of the patch antennae
114 and 115 are orthogonal with respect to the dipole antenna 111
and thus are orthogonally polarized leading to greater isolation
and link efficiency. Typically, the patch antennae 114 and 115 are
vertically polarized and the dipole antenna 111 is horizontally
polarized.
[0033] As shown in arrangement 110, a conductive barrier, such as
an isolation fence 112, can be used to provide an electromagnetic
barrier between the physical regions of the patch antennae 114 and
115 and the dipole section 111 which are most likely to couple into
each other. In arrangement 120, the isolation fence is not present.
The isolation fence can be electrically coupled to the ground plane
113 to further enhance common mode noise rejection.
[0034] The result of the use of the dipole patch array in various
embodiments with a selected one of the patch antennae 114 and 115
and the dipole antenna 111 can be seen in FIG. 2, where a radiation
plot shows the gain versus angle of azimuth and elevation are shown
for the dipole antenna 111. In a trace 210, the gain vs. azimuth
angle of the dipole antenna 111 is shown for an exemplary dipole
patch array without the fence 112. Trace 211 shows the gain vs.
elevation angle of the dipole antenna 111 without the fence 112. A
peak gain of 4.7 dBi is realized with an azimuth of 160.degree. and
elevation of 75.degree.. When the fence 112 is used, the
improvement in peak gain and directivity can be seen. For example,
a trace 220 shows the gain vs. azimuth angle of the dipole antenna
111 and a trace 221 shows the gain vs. elevation angle of the
dipole antenna 111 with the fence 112. With the fence 112 in use, a
peak gain of 5.5 dBi is realized with an azimuth of 130.degree. and
elevation of 65.degree..
[0035] Additional results of the use of the dipole patch array in
various embodiments with a selected one of the patch antennae 114
and 115 and the dipole antenna 111 can be seen in FIG. 3, where a
radiation plot shows the gain versus angle of azimuth and elevation
are shown for a selected one of the patch antennae 114 and 115. In
a trace 310, the gain vs. azimuth angle of the selected patch
antennae 114 and 115 is shown for an exemplary dipole patch array
without the fence 112. Trace 311 shows the gain vs. elevation angle
of the selected patch antennae 114 and 115 without the fence 112. A
peak gain of 7.8 dBi is realized with an azimuth of 65.degree. and
elevation of 70.degree.. When the fence 112 is used, improved roll
off at the outer pattern regions is seen. For example, a trace 320
shows the gain vs. azimuth angle of the selected patch antennae 114
and 115 and a trace 321 shows the gain vs. elevation angle of the
selected patch antennae 114 and 115 with the fence 112. With the
fence 112 in use, a peak gain of 7.5 dBi is realized with an
azimuth of 70.degree. and elevation of 75.degree., however, as
noted the roll off in the greater than 90.degree. and less than
-90.degree. regions, which regions are most likely to cause
interference with the dipole antenna 111, is improved.
[0036] The above described performance relations are better seen in
the combined plot shown in FIG. 4. Therein, a radiation pattern 430
of the dipole antenna 111 is shown against radiation patterns 410
and 420 of the patch antennae 114 and 115 in an exemplary dipole
patch array using a fence 112. As a result of the configuration of
the antennae and the use of the fence isolation, particularly at
the desired frequency for the present example, such as the 2.44 GHz
frequency band commonly associated with the IEEE 802.11(b)
specification or the 802.11(g) specification commonly referred to
as "Wi-Fi," as shown in FIG. 5. It should be appreciated that the
present invention can also be used in other networks or systems
such as Wi-Max systems, Wi-Bro systems, and/or systems operating in
accordance with well-known IEEE "802" standards such as 802.16
systems and 802.20 systems including their respective subparts,
such as 802.16(e) systems, or in any TDD wireless system. A trace
510 shows the isolation between antenna elements vs. frequency for
an exemplary dipole patch array without a fence 112. It should be
noted that within the 2.44 GHz band, the isolation is locally poor
in comparison to a trace 511, which shows isolation with the fence
112 and shows improved isolation in the 2.44 GHz band.
[0037] It will be appreciated that the use of fence 112 can lead to
further improvement, for example in the area of antenna matching,
particularly for the selected one of the patch antennae 114 and 115
as can be seen in FIG. 6. A trace 610 shows the VSWR vs. frequency
for the dipole antenna 111 without the fence 112. It will be noted
that the VSWR is relatively flat across the frequency range which
is desirable. A trace 611 shows the VSWR vs. frequency for the
selected one of the patch antennae 114 and 115 without the fence
112. As can be seen, the VSWR in the desired bandwidth is poor for
the selected one of the patch antennae 114 and 115 without the
fence 112 indicating mismatching and reduced radiation and
reception efficiency. By using the fence 112, only marginal
improvement in VSWR is realized for the dipole antenna 111 as shown
in a trace 620. However, with the use of the fence 112, VSWR
performance is drastically improved for the selected one of the
patch antennae 114 and 115 as shown in a trace 621.
[0038] In accordance with various alternative embodiments, as noted
above, the exemplary repeater can be configured as a monopole patch
array 700 as shown in FIG. 7. As with the dipole configuration, a
pair of parallel patch antennae 714 and 715 can be arranged on
either side of a ground plane 713, which can also be used as the
circuit board for the repeater circuitry. Each of the patch
antennae 714 and 715 are arranged in parallel with the ground plane
713 and can be printed on a printed circuit board (PCB), wiring
board or the like, or can be constructed of a stamped metal portion
embedded in a plastic housing. A planar portion of the PCB
associated with the ground plane 713 can contain an antenna, such
as a monopole antenna 711 configured, for example, as an embedded
trace thereon and directed toward the client side of the repeater.
It will be appreciated that the orientation of the patch antennae
714 and 715 are orthogonal with respect to the monopole antenna 711
and thus are orthogonally polarized leading to greater isolation
and link efficiency. Typically, the patch antennae 714 and 715 are
vertically polarized and the monopole antenna 711 is horizontally
polarized.
[0039] An isolation fence 712 can be used to provide an
electromagnetic barrier between the physical regions of the patch
antennae 714 and 715 and the monopole antenna 711 which are most
likely to couple into each other. The isolation fence can be
electrically coupled to the ground plane 713 to further enhance
common mode noise rejection.
[0040] The result of the use of the monopole patch array in various
embodiments with a selected one of the patch antennae 714 and 715
and the monopole antenna 711 can be seen in FIG. 8, where a
radiation plot shows the gain versus angle of azimuth and elevation
are shown for the monopole antenna 711. In a trace 810, the gain
vs. azimuth angle of the monopole antenna 711 is shown for an
exemplary monopole patch array without the fence 712. Trace 811
shows the gain vs. elevation angle of the monopole antenna 711
without the fence 712. When the fence 712 is used, an improvement
in localized directivity can be seen. For example, a trace 820
shows the gain vs. azimuth angle of the monopole antenna 711 and a
trace 821 shows the gain vs. elevation angle of the monopole
antenna 711 with the fence 712. With the fence 712 in use, a peak
azimuthal gain of 1.8 dBi is realized an a peak elevation gain of
2.8 dBi is realized.
[0041] Additional results of the use of the monopole patch array in
various embodiments with a selected one of the patch antennae 714
and 715 and the monopole antenna 711 can be seen in FIG. 9, where a
radiation plot shows the gain versus angle of azimuth and elevation
are shown for a selected one of the patch antennae 714 and 715. In
a trace 910, the gain vs. azimuth angle of the selected patch
antennae 714 and 715 is shown for an exemplary monopole patch array
without the fence 712. Trace 911 shows the gain vs. elevation angle
of the selected patch antennae 714 and 715 without the fence 712. A
peak gain of 7.6 dBi is realized with an azimuth of 60.degree. and
elevation of 80.degree.. When the fence 712 is used, some change in
roll off at the outer pattern regions is seen however performance
closely matches non-fence performance. For example, a trace 920
shows the gain vs. azimuth angle of the selected patch antennae 714
and 715 and a trace 921 shows the gain vs. elevation angle of the
selected patch antennae 714 and 715 with the fence 712. With the
fence 712 in use, a peak gain of 7.4 dBi is realized with an
azimuth of 60.degree. and elevation of 80.degree., which is nearly
identical to the performance without the fence. Likewise, isolation
with the use of the fence shows nominal improvement as shown in
FIG. 10. A trace 1010 shows the isolation between antenna elements
vs. frequency for an exemplary monopole patch array without a fence
712. In comparison to a trace 1011, which shows isolation with the
fence 712, a small margin of improved isolation is realized.
[0042] Use of fence 712 leads to only marginal improvement in VSWR
for the selected one of the patch antennae 714 and 715 as can be
seen in FIG. 11, while actually decreasing the VSWR performance
slightly for the monopole antenna 711. A trace 1110 shows the VSWR
vs. frequency for the monopole antenna 711 without the fence 712.
It will be noted that the VSWR is relatively flat across the
frequency range which is desirable. A trace 1111 shows the VSWR vs.
frequency for the selected one of the patch antennae 714 and 715
without the fence 712. As can be seen, the VSWR is relatively flat
across the frequency range which is desirable. By using the fence
712, a marginal degradation in VSWR is realized for the monopole
antenna 711 as shown in a trace 1120. With the use of the fence
712, VSWR performance is only nominally improved for the selected
one of the patch antennae 714 and 715 as shown in a trace 1121.
[0043] It will be appreciated that the exemplary dipole or monopole
patch array along with the repeater electronics can be efficiently
housed in a compact enclosure 1200 as shown in FIG. 12A. The
structure of the enclosure 1200 can be such that it will be
naturally oriented in one of two ways however, instructions can
guide a used in how to place the enclosure to maximize signal
reception. An exemplary dipole patch array is shown in FIG. 12B,
where a ground plane 1213, preferably incorporated with a PCB for
the repeater electronics can be arranged in parallel between two
patch antennae 1214 and 1215 using, for example, standoffs 1220. It
will be appreciated that in some embodiments, in order to reduce
costs, standoffs will be unnecessary as the enclosure 1200 can be
molded with slots or other fixative structures to hold the ground
plane 1213 and the two patch antennae 1214 and 1215 in position
when the enclosure 1200 is assembled. An isolation fence 1212 can
be used as noted above to improve isolation in many instances. In
alternative embodiments as shown in FIG. 13A and FIG. 13B, a
claimshell enclosure 1310 can be used with a ground plane/PCB
substrate 1313 positioned therewithin and a patch antenna 1314 and
client side antenna 1311, which can be a dipole antenna, a monopole
antenna or the like, for example, as described hereinabove.
[0044] As described above, the directional antenna includes two or
more antennae such as patch antennae which can be switched as
illustrated in exemplary scenario 1400 as shown in FIG. 14. An
exemplary repeater unit can include a directional antenna section
1410, an omni directional or quasi omni directional antenna section
1420 and a radio frequency (RF) front end section 1430 some or all
of which can be integrated into, for example, an integrated antenna
array. The directional antenna section 1410 includes a first
directional antenna 1411, a second directional antenna 1412, and
possibly additional antenna which can include patch portions etched
into a printed circuit board material or can be stamped from metal
and laminated as described hereinabove. The first directional
antenna 1411 and the second directional antenna 1412 or additional
antenna can be switched into operation using an antenna switch 1413
depending on which of the directional antenna have the best signal
characteristics. In a set up procedure, which can be performed by a
user, the repeater is positioned near the desired base station or
AP and a button is pressed. Input is provided to the repeater that
will allow it to be configured according to a button press
procedure such as that described in pending application U.S. patent
application Ser. No. 10/536,471, entitled "IMPROVED WIRELESS
NETWORK REPEATER," filed May 26, 2005, attorney docket no.
WF02-09/27-007 and incorporated herein by reference. The integrated
antenna array can be housed in a compact housing, for example as
described hereinabove in connection with FIG. 12.
[0045] Accordingly, the exemplary repeater can select the first
directional antenna 1411 and scans all allowable frequency channels
for beacon transmissions from an AP. The repeater stores each
received beacon and information about the quality of the signal
associated with the beacon in a table. The repeater then selects
the second directional antenna 1412 and repeats the scan of the
allowable frequency channels as noted above. If additional
directional antennae are used, then the repeater will scan and
record beacon signal information for all the directional antennae
and store the information in a table. When scanning is compete for
all the directional antennae, the directional antenna associated
with the beacon signal information having the best quality metric
such as power, signal-to-noise-ration (SNR) or the like between the
two antennae will be selected and identified as the master or
target AP and an identifier such as a BSS_ID, which is typically
the MAC address of the target AP, is stored. The identifier can
then be provided to the repeater showing the "affiliated" AP for
reference during subsequent start ups. Once the affiliated AP
information, such as the BSS_ID for the affiliated AP, is stored
and the scanning task is indicated as being complete, the user will
re-position the repeater.
[0046] Once the repeater is relocated and powered, the above
described scan process or a modified scan process can be repeated.
However, once information associate with the affiliated AP is
obtained in a first scan or a first portion of a scanning
procedure, it can be used in making the decision as to which patch
antenna is deemed to have the best signal quality and therefore is
selected as the patch for initial operation. It will further be
appreciated that in some embodiments, a combined scan procedure
that locates APs and selects a best signal patch antenna can be
used in one initialization procedure. When initialization is
complete, a "configured" indication is provided to a user such as a
simple LED indicator (not shown).
[0047] Additional scanning can be performed based on various scan
criteria. For example, additional scans can be performed
periodically after the expiration of a time interval, when a
quality metric, including a received power level of the AP signal,
drops below a threshold, when the packet error rate exceeds a
threshold value, or when various other criteria are met. Additional
scanning can also be performed opportunistically during periods
where no important information is or will be transmitted over the
repeater link based, for example, on known characteristics of the
wireless MAC protocol.
[0048] To illustrate the placement of an exemplary repeater in a
wireless TDD system, an exemplary wireless network scenario 1500 is
shown in FIG. 15. Therein a base station 1510 can communicate with
a repeater 1520 for communication with a client 1530. An air
interface 1511 can be used for communication to and from the base
station 1510 and the repeater 1520 through one or more directional
antennae 1521 one of which can be selected for optimum operation
using switch 1522. The selection of the antennae 1521 can be
changed in accordance with a periodic scanning interval or a
scanning performed based on additional criteria as described
hereinabove. A repeater unit 1523 is capable of simultaneously
handing transmission and reception of information to and from the
base station 1510 while communicating with the client 1530 using a
directional antenna 1524, which broadcasts the repeated signal to
client 1530 over air interface 1525 and also receives signal energy
from client 1530 to re-transmit to base station 1510. It will also
be appreciated that depending on the particular embodiment, the
repeater 1523 can act as a physical (PHY) layer repeater simply
re-transmitting without parsing the protocol information such as
the packet header or the like, or can be provided with additional
intelligence such that the repeater 1523 can provide additional
higher layer protocol functions, such as media access control (MAC)
functions which require header parsing, error correction, routing,
and the like typically associated with a higher layer protocol.
[0049] In accordance with some embodiments, multiple antenna
modules can be constructed within the same repeater or device, such
as multiple directional antennae or antenna pairs as described
above and multiple omni or quasi-omni-directional antennae for use,
for example, in a multiple-input-multiple-output (MIMO) environment
or system.
[0050] This disclosure is intended to explain how to fashion and
use various embodiments in accordance with the invention rather
than to limit the true, intended, and fair scope and spirit
thereof. The foregoing description is not intended to be exhaustive
or to limit the invention to the precise form disclosed.
Modifications or variations are possible in light of the above
teachings. The embodiment(s) was chosen and described to provide
the best illustration of the principles of the invention and its
practical application, and to enable one of ordinary skill in the
art to utilize the invention in various embodiments and with
various modifications as are suited to the particular use
contemplated. All such modifications and variations are within the
scope of the invention. The various circuits described above can be
implemented in discrete circuits or integrated circuits, as desired
by implementation. Further, portions of the invention may be
implemented in software or the like as will be appreciated by one
of skill in the art and can be embodied as methods associated with
the content described herein.
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