CA2433632A1 - A method and system for a smart antenna - Google Patents
A method and system for a smart antenna Download PDFInfo
- Publication number
- CA2433632A1 CA2433632A1 CA 2433632 CA2433632A CA2433632A1 CA 2433632 A1 CA2433632 A1 CA 2433632A1 CA 2433632 CA2433632 CA 2433632 CA 2433632 A CA2433632 A CA 2433632A CA 2433632 A1 CA2433632 A1 CA 2433632A1
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- Prior art keywords
- path
- antenna
- phase
- variable
- phase shifter
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
- H04B7/0837—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using pre-detection combining
- H04B7/0842—Weighted combining
- H04B7/086—Weighted combining using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/007—Details of, or arrangements associated with, antennas specially adapted for indoor communication
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
- H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
- H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
- H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
- H04B7/0617—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal for beam forming
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
- H04B7/0837—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using pre-detection combining
- H04B7/084—Equal gain combining, only phase adjustments
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
- H04B7/0837—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using pre-detection combining
- H04B7/0842—Weighted combining
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Variable-Direction Aerials And Aerial Arrays (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
A system and method for a smart antenna is provided. A system includes a receiver and a transmitter. The receiver includes a pair of antenna path. The first path includes a variable phase shifter and a variable gain amplifier, and the second path includes a variable gain amplifier. For beam forming, the phase shift value of the phase shifter is changed. For example, the phase shift value is changed sequentially within 10-18 packets. For example, the phase shift value is changed in accordance with certain equations within 4 packets. The phase and gain of a receiver mode is applied to a transmitter mode.
Description
A method and system for a smart antenna FIELD OF THE INVENTION:
This invention relates to a signal processing, more particularly to a method and system for a smart antenna.
BACKGROUND OF THE INVENTION
Figure 1 shows a conventional wireless local area network (WLAN) system 10.
The WLAN system 10 includes one access point AP and wireless nodes #1-#3. In the system 10, Electromagnetic signal on air (EM) changes slowly (5-10 seconds).
The conventional system 20 has the following problems:
~5 1- Dead-spots 2- Range 3- Power consumption 4- Interference It is therefore desirable to provide a new smart antenna system and method 20 of operating the smart antenna system.
SUMMARY OF THE INVENTION:
It is an object of the invention to provide a novel smart antenna system and a 25 method that obviate or mitigate at least one of the disadvantages of existing systems.
!n accordance with an aspect of the present invention, there is provided a system for a smart antenna. The system includes: first and second antennas, the phase difference between the first and second antenna being 0; a first path for a first so antenna, which has a variable phase shifter for phase shifting a signal received on the first antenna, and a variable gain amplifier; a second path for a second antenna which has a variable gain amplifier; a combiner for combining the outputs of the first and second paths; and a controller for changing a phase shift value ca of the variable phase shifter at each packet within a certain period to find a maximum 8.
In accordance with a further aspect of the present invention, there is provided a method of operating a smart antenna for beam forming. The method includes the step of; at a first path for a first antenna, phase shifting a signal received on the first antenna at a variable phase shifter and gain adjusting the output of the variable phase shifter; at a second path for a second antenna, gain adjusting a signal received on the second antenna, the phase difference between the first and second antenna being 8; combining the outputs of the first and second paths, and changing a phase shift value ~ of the variable phase shifter at each packet within a certain period to find a maximum e.
Other aspects and features of the present invention will be readily apparent to 15 those skilled in the art from a review of the following detailed description of preferred embodiments in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS:
2o The invention will be further understood from the following description with reference to the drawings in which:
Figure 1 is a diagram showing a conventional WLAN system;
Figure 2 is a diagram showing packets for beam forming in accordance with an 25 embodiment of the present invention;
Figure 3 is a diagram showing a smart antenna receiver in a smart antenna system in accordance with the embodiment of the present invention;
Figure 4 is a flow chart showing operation for beam forming in the smart antenna of Figure 3;
3o Figure 5 is a diagram showing a smart antenna transmitter in the smart antenna system of Figure 3;
Figure 6 is a diagram showing a first embodiment of operation far beam forming of Figure 3;
Figure 7 is a diagram showing a second embodiment of operation for beam forming Figure 3; and Figure 8 is a diagram showing a third embodiment of operation for beam forming of Figure 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:
A smart antenna system in accordance with an embodiment of the present invention and algorithm for beam forming at a wireless node is now described.
The algorithm is applied to Home and/or Small Office/Home Office (SOHO).
-!n presence of two or more APs, this algorithm disables itself and becomes a conventional WLAN. For example, inconsistent Received Signal Strength Indicator 15 (RSSI) is used for an indictor to find multiple APs.
- A slow algorithm (1 second beam forming interval) in accordance with one embodiment of the invention is good enough. For faster beam forming, shorter beam forming intervals in accordance with further embodiment of the present invention is used (Figures 2-6).
20 - For example, as shown in Figures 2 and 4, 10 packets (10 mS) are used for beam forming. For more accurate beam forming or higher antennas, more than 10 packets are used as shown in Figure 5.
- This results in less than 1 % packet loss.
- Protocol independent, 802.11 a/bJg, BT etc.
Figure 3 shows a smart antenna receiver 20 in accordance with the embodiment of the invention. The smart antenna receiver 20 includes two antennas A1 and A2 and antenna paths 30 and 40. The path 30 has a variable phase shifter 32 that receives a signal from the antenna A1, and a variable gain amplifier 34 that 3o receives the output of the variable phase shifter 32. The path 40 has a variable gain amplifier 42 that receives a signs! from the antenna A2. The outputs of the paths 30 and 40 are combined by a combiner 44.
A~ Sin(wt) represents a signal on the antenna path 30. A2 Sin(wt+8) represents a signal on the antenna path 40.
The phase shift value c~ at the variable phase shifter 32 is changed so as to be equal to 8. The system of Figure 3 performs beam forming by changing ~.
Figure 4 is a flow diagram showing the operation for beam forming in the system of Figure 3.
Figure 5 shows a smart antenna transmitter ~60. The transmitter 60 has variable phase shifters.
Phase and gain of each antenna path 30, 40 of Figure 3 is set in receive mode o for maximum performance. Same phase and gain can be applied for transmit mode.
Figure 6 shows a first algorithm for beam forming applied to the smart antenna receiver 20 of Figure 3. The algorithm of Figure 6 uses 10 packets at the maximum for beam forming.
Using the first packet p1, the absolute value of A~ is measured. Using the second packet p2, the absolute value of A2 is measured. At the subsequent packets, ~ is alternatively set to 0, 45, 90, 135, 180, 225, 270 and 315. At packet p4-p10, the system continuously increases phase by 45 steps and measures /observes received signal level to find optimum phase that gives maximum reception, or minimum 2o interference. There are two known smart antenna general algorithms: 1-maximizing wanted received signal 2-minimizing unwanted interference.
The feature of the algorithm is as follows:
1- Once maximum found (8} by observing (measuring received signal level of smart 2s antenna receiver, beam forming will be stopped 2- Maximum 10 tries {i.e. Maximum 10 packets) 3- Less than 45° cD phase error {45° error--> 1.37 dB loss}
4- Adaptive phase step (Smarter algorithm) 3o In Figure 6, fixed phase steps (45 degrees) are used. A smarter algorithm changes this step by looking behavior of the system during process of algorithm. The smarter algorithm has a complex decision making capability to decide and change phase steps during the process of finding optimum phase.
Figure 7 shows a second algorithm for beam forming applied to the smart antenna receiver 20 of Figure 3. The algorithm of Figure 7 uses 18 packets at the 5 maximum for beam forming.
Using the first packet p1, the absolute value of A~ is measured. Using the second packet p2, the absolute value of A2 is measured. At the subsequent packets, ~ is alternatively set to 0, 22.5, 45, ..., 292.5, 315, and 337.5.
The feature of the algorithm is as follows:
1- Once maximum found (8), beam forming will be stopped 2- Maximum 18 tries (i.e. Maximum 18 packets) 3- Less than 22.5° c~ phase error (22.5° error--r 0.33 dB loss) 4- Adaptive phase step (Smarter algorithm) Figure 8 shows a third algorithm for beam forming applied to the smart antenna receiver 20 of Figure 3. In Figure 6, V~=A~ Sin(wt) represents a signal on the antenna path 30 of Figure 1, and Vz=A2Sin(wt+8) represents a signal on the antenna path 40 of Figure 1.
2o Using the first packet p1, the absolute value of A~ is measured. Using the second packet p2, the absolute value of Az is measured. At the third packet p3, ~ is set in accordance with the following equation:
IY xA I +IY xAI
~=kx180°+2xcos-' ' 2xAlxAz~
At the fourth packet p4, K (K: integer} is set to 1 or 0 in accordance with the following equation:
if (V~X~Az~)+(VZX~A~i)=0 -i K=1 if (V~XfAz~)+(VZX~A~~)>0 -~ K=0 According to the embodiment of the present invention, the algorithm as shown in Figure 8 is faster than that of Figures 6-7. On the other hand, the algorithm of Figures 6-7 is robust.
While particular embodiments of the present invention have been shown and described, changes and modifications may be made to such embodiments without departing from the true scope of the invention.
This invention relates to a signal processing, more particularly to a method and system for a smart antenna.
BACKGROUND OF THE INVENTION
Figure 1 shows a conventional wireless local area network (WLAN) system 10.
The WLAN system 10 includes one access point AP and wireless nodes #1-#3. In the system 10, Electromagnetic signal on air (EM) changes slowly (5-10 seconds).
The conventional system 20 has the following problems:
~5 1- Dead-spots 2- Range 3- Power consumption 4- Interference It is therefore desirable to provide a new smart antenna system and method 20 of operating the smart antenna system.
SUMMARY OF THE INVENTION:
It is an object of the invention to provide a novel smart antenna system and a 25 method that obviate or mitigate at least one of the disadvantages of existing systems.
!n accordance with an aspect of the present invention, there is provided a system for a smart antenna. The system includes: first and second antennas, the phase difference between the first and second antenna being 0; a first path for a first so antenna, which has a variable phase shifter for phase shifting a signal received on the first antenna, and a variable gain amplifier; a second path for a second antenna which has a variable gain amplifier; a combiner for combining the outputs of the first and second paths; and a controller for changing a phase shift value ca of the variable phase shifter at each packet within a certain period to find a maximum 8.
In accordance with a further aspect of the present invention, there is provided a method of operating a smart antenna for beam forming. The method includes the step of; at a first path for a first antenna, phase shifting a signal received on the first antenna at a variable phase shifter and gain adjusting the output of the variable phase shifter; at a second path for a second antenna, gain adjusting a signal received on the second antenna, the phase difference between the first and second antenna being 8; combining the outputs of the first and second paths, and changing a phase shift value ~ of the variable phase shifter at each packet within a certain period to find a maximum e.
Other aspects and features of the present invention will be readily apparent to 15 those skilled in the art from a review of the following detailed description of preferred embodiments in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS:
2o The invention will be further understood from the following description with reference to the drawings in which:
Figure 1 is a diagram showing a conventional WLAN system;
Figure 2 is a diagram showing packets for beam forming in accordance with an 25 embodiment of the present invention;
Figure 3 is a diagram showing a smart antenna receiver in a smart antenna system in accordance with the embodiment of the present invention;
Figure 4 is a flow chart showing operation for beam forming in the smart antenna of Figure 3;
3o Figure 5 is a diagram showing a smart antenna transmitter in the smart antenna system of Figure 3;
Figure 6 is a diagram showing a first embodiment of operation far beam forming of Figure 3;
Figure 7 is a diagram showing a second embodiment of operation for beam forming Figure 3; and Figure 8 is a diagram showing a third embodiment of operation for beam forming of Figure 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:
A smart antenna system in accordance with an embodiment of the present invention and algorithm for beam forming at a wireless node is now described.
The algorithm is applied to Home and/or Small Office/Home Office (SOHO).
-!n presence of two or more APs, this algorithm disables itself and becomes a conventional WLAN. For example, inconsistent Received Signal Strength Indicator 15 (RSSI) is used for an indictor to find multiple APs.
- A slow algorithm (1 second beam forming interval) in accordance with one embodiment of the invention is good enough. For faster beam forming, shorter beam forming intervals in accordance with further embodiment of the present invention is used (Figures 2-6).
20 - For example, as shown in Figures 2 and 4, 10 packets (10 mS) are used for beam forming. For more accurate beam forming or higher antennas, more than 10 packets are used as shown in Figure 5.
- This results in less than 1 % packet loss.
- Protocol independent, 802.11 a/bJg, BT etc.
Figure 3 shows a smart antenna receiver 20 in accordance with the embodiment of the invention. The smart antenna receiver 20 includes two antennas A1 and A2 and antenna paths 30 and 40. The path 30 has a variable phase shifter 32 that receives a signal from the antenna A1, and a variable gain amplifier 34 that 3o receives the output of the variable phase shifter 32. The path 40 has a variable gain amplifier 42 that receives a signs! from the antenna A2. The outputs of the paths 30 and 40 are combined by a combiner 44.
A~ Sin(wt) represents a signal on the antenna path 30. A2 Sin(wt+8) represents a signal on the antenna path 40.
The phase shift value c~ at the variable phase shifter 32 is changed so as to be equal to 8. The system of Figure 3 performs beam forming by changing ~.
Figure 4 is a flow diagram showing the operation for beam forming in the system of Figure 3.
Figure 5 shows a smart antenna transmitter ~60. The transmitter 60 has variable phase shifters.
Phase and gain of each antenna path 30, 40 of Figure 3 is set in receive mode o for maximum performance. Same phase and gain can be applied for transmit mode.
Figure 6 shows a first algorithm for beam forming applied to the smart antenna receiver 20 of Figure 3. The algorithm of Figure 6 uses 10 packets at the maximum for beam forming.
Using the first packet p1, the absolute value of A~ is measured. Using the second packet p2, the absolute value of A2 is measured. At the subsequent packets, ~ is alternatively set to 0, 45, 90, 135, 180, 225, 270 and 315. At packet p4-p10, the system continuously increases phase by 45 steps and measures /observes received signal level to find optimum phase that gives maximum reception, or minimum 2o interference. There are two known smart antenna general algorithms: 1-maximizing wanted received signal 2-minimizing unwanted interference.
The feature of the algorithm is as follows:
1- Once maximum found (8} by observing (measuring received signal level of smart 2s antenna receiver, beam forming will be stopped 2- Maximum 10 tries {i.e. Maximum 10 packets) 3- Less than 45° cD phase error {45° error--> 1.37 dB loss}
4- Adaptive phase step (Smarter algorithm) 3o In Figure 6, fixed phase steps (45 degrees) are used. A smarter algorithm changes this step by looking behavior of the system during process of algorithm. The smarter algorithm has a complex decision making capability to decide and change phase steps during the process of finding optimum phase.
Figure 7 shows a second algorithm for beam forming applied to the smart antenna receiver 20 of Figure 3. The algorithm of Figure 7 uses 18 packets at the 5 maximum for beam forming.
Using the first packet p1, the absolute value of A~ is measured. Using the second packet p2, the absolute value of A2 is measured. At the subsequent packets, ~ is alternatively set to 0, 22.5, 45, ..., 292.5, 315, and 337.5.
The feature of the algorithm is as follows:
1- Once maximum found (8), beam forming will be stopped 2- Maximum 18 tries (i.e. Maximum 18 packets) 3- Less than 22.5° c~ phase error (22.5° error--r 0.33 dB loss) 4- Adaptive phase step (Smarter algorithm) Figure 8 shows a third algorithm for beam forming applied to the smart antenna receiver 20 of Figure 3. In Figure 6, V~=A~ Sin(wt) represents a signal on the antenna path 30 of Figure 1, and Vz=A2Sin(wt+8) represents a signal on the antenna path 40 of Figure 1.
2o Using the first packet p1, the absolute value of A~ is measured. Using the second packet p2, the absolute value of Az is measured. At the third packet p3, ~ is set in accordance with the following equation:
IY xA I +IY xAI
~=kx180°+2xcos-' ' 2xAlxAz~
At the fourth packet p4, K (K: integer} is set to 1 or 0 in accordance with the following equation:
if (V~X~Az~)+(VZX~A~i)=0 -i K=1 if (V~XfAz~)+(VZX~A~~)>0 -~ K=0 According to the embodiment of the present invention, the algorithm as shown in Figure 8 is faster than that of Figures 6-7. On the other hand, the algorithm of Figures 6-7 is robust.
While particular embodiments of the present invention have been shown and described, changes and modifications may be made to such embodiments without departing from the true scope of the invention.
Claims (6)
1. A system for a smart antenna comprising;
first and second antennas, the phase difference between the first and second antenna being .theta.;
a first path for a first antenna, which has a variable phase shifter for phase shifting a signal received on the first antenna, and a variable gain amplifier;
a second path for a second antenna which has a variable gain amplifier;
a combiner for combining the outputs of the first and second paths, and a controller for changing a phase shift value .PHI. of the variable phase shifter at each packet within a certain period to find a maximum .theta..
first and second antennas, the phase difference between the first and second antenna being .theta.;
a first path for a first antenna, which has a variable phase shifter for phase shifting a signal received on the first antenna, and a variable gain amplifier;
a second path for a second antenna which has a variable gain amplifier;
a combiner for combining the outputs of the first and second paths, and a controller for changing a phase shift value .PHI. of the variable phase shifter at each packet within a certain period to find a maximum .theta..
2. The system according to claim 1, wherein the controller sets the phase shift value .PHI. in accordance with the following equation:
where V1=A1 Sin(.omega.t) represents a signal on the first path, and V2=A2 Sin(.omega.t+.theta.) represents a signal on the second path, wherein the controller sets "K" at a next packet in accordance with the following equation:
if (V1X¦A2¦)+(V2X¦A1¦)=0 .fwdarw. K=1 if (V1X¦A2¦)+(V2X¦A1¦)>0 .fwdarw. K=0
where V1=A1 Sin(.omega.t) represents a signal on the first path, and V2=A2 Sin(.omega.t+.theta.) represents a signal on the second path, wherein the controller sets "K" at a next packet in accordance with the following equation:
if (V1X¦A2¦)+(V2X¦A1¦)=0 .fwdarw. K=1 if (V1X¦A2¦)+(V2X¦A1¦)>0 .fwdarw. K=0
3. The system according to claim 1 further comprising a transmitter for transmitting a signal, the transmitter has a third path having a variable phase shifter for phase shifting a signal, and a fourth path, the phase of the variable phase shifter in the firth path being applied to that of the third path.
4. A method of operating a smart antenna for beam forming, the method comprising the step of;
at a first path for a first antenna, phase shifting a signal received on the first antenna at a variable phase shifter and gain adjusting the output of the variable phase shifter;
at a second path for a second antenna, gain adjusting a signal received on the second antenna, the phase difference between the first and second antenna being .theta.;
combining the outputs of the first and second paths, changing a phase shift value .PHI. of the variable phase shifter at each packet within a certain period to find a maximum .theta..
at a first path for a first antenna, phase shifting a signal received on the first antenna at a variable phase shifter and gain adjusting the output of the variable phase shifter;
at a second path for a second antenna, gain adjusting a signal received on the second antenna, the phase difference between the first and second antenna being .theta.;
combining the outputs of the first and second paths, changing a phase shift value .PHI. of the variable phase shifter at each packet within a certain period to find a maximum .theta..
5. A method of claim 4, wherein the step of controlling includes the step of setting the phase shift value .PHI. in accordance with the following equation:
where V1=A1 Sin(.omega.t) represents a signal on the first path, and V2=A2 Sin(.omega.t+.theta.) represents a signal on the second path, the step of controlling further includes the step of setting "K" at a next packet in accordance with the following equation:
if (V1X¦A2¦)+(V2X¦A1¦)=0 .fwdarw. K=1 if (V1X¦A2¦)+(V2X¦A1¦)>0 .fwdarw. K=0
where V1=A1 Sin(.omega.t) represents a signal on the first path, and V2=A2 Sin(.omega.t+.theta.) represents a signal on the second path, the step of controlling further includes the step of setting "K" at a next packet in accordance with the following equation:
if (V1X¦A2¦)+(V2X¦A1¦)=0 .fwdarw. K=1 if (V1X¦A2¦)+(V2X¦A1¦)>0 .fwdarw. K=0
6. A method of claim 4 further comprising the step of applying the phase in the variable phase shifter at the first path to a variable phase shifter at a transmitter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2433632 CA2433632A1 (en) | 2003-06-26 | 2003-06-26 | A method and system for a smart antenna |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2433632 CA2433632A1 (en) | 2003-06-26 | 2003-06-26 | A method and system for a smart antenna |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2433632A1 true CA2433632A1 (en) | 2004-12-26 |
Family
ID=33569454
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2433632 Abandoned CA2433632A1 (en) | 2003-06-26 | 2003-06-26 | A method and system for a smart antenna |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2433632A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011023211A1 (en) * | 2009-08-28 | 2011-03-03 | Verigy (Singapore) Pte. Ltd. | Apparatus and method for wireless testing of a plurality of transmit paths and a plurality of receive paths of an electronic device |
| EP2624478A4 (en) * | 2010-09-30 | 2017-06-14 | Panasonic Corporation | Wireless communication device |
-
2003
- 2003-06-26 CA CA 2433632 patent/CA2433632A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011023211A1 (en) * | 2009-08-28 | 2011-03-03 | Verigy (Singapore) Pte. Ltd. | Apparatus and method for wireless testing of a plurality of transmit paths and a plurality of receive paths of an electronic device |
| EP2624478A4 (en) * | 2010-09-30 | 2017-06-14 | Panasonic Corporation | Wireless communication device |
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|---|---|---|---|
| FZDE | Dead |