CONTROL METHOD OF WIRELESS COMMUNICATION SYSTEM, WIRELESS COMMUNICATION SYSTEM, WIRELESS COMMUNICATION APPARATUS, AND ADJUSTMENT METHOD OF ARRAY WEIGHT VECTOR
First Claim
1. A control method of a wireless communication system comprising first and second communication devices, the second communication device comprising an antenna array, and an array weight vector (hereinafter “
- AWV”
) control circuit that changes at least one of amplitudes and phases of transmission signals or received signals of a plurality of antenna elements included in the antenna array, the control method comprising;
when an AWV of at least two antenna elements among the plurality of antenna elements included in the antenna array is independently controlled,(a) receiving, in the second communication device, while scanning a beam direction by changing an AWV of the antenna array of the second communication device, a training signal transmitted from the first communication device by using a fixed beam pattern;
(b) determining at least one direction of arrival (DOA) in the second communication device based on reception signal characteristics of the training signal;
(c) receiving, in the second communication device, the training signal transmitted by the first communication device while changing the AWV of the antenna array of the second communication device in such a manner that a null direction or a direction close to the null direction is successively pointed to one by one from the at least one DOA;
(d) comparing a reception signal characteristic obtained in the step (a) with a reception signal characteristic obtained in the step (c) for each of the at least one DOA, and specifying a DOA for which a ratio or a difference between these reception signal characteristics is smaller than a predefined threshold;
(e) obtaining at least one AWV each having a main beam direction or a sub-beam direction close to the main beam pointing to one of the at least one DOA in the second communication device determined in the step (b) except for the DOA specified in the step (d); and
(f) using the at least one AWV obtained in the step (e) for communication between the first and second communication devices.
1 Assignment
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Accused Products
Abstract
To suppress adverse effects caused by side lobes of an antenna array when an AWV to be used for communication is determined based on a transmission/reception result of a training signal. A first transceiver generates a fixed beam pattern and transmits a training signal. In that state, a second transceiver receives the training signal while scanning for the main beam direction, and thereby determines a plurality of direction of arrivals (DOAs). Next, the second transceiver receives the training signal in a state where the signal receptions from the plurality of DODs are restricted one by one (e.g., a null direction or a direction close to the null direction is fixed in the DOA), and calculates the change of the signal characteristics from that obtained in the first reception. The transceivers obtain and use at least one AWV having the main beam direction or a sub-beam direction close to the main beam pointing to one of the plurality of DOAs except for the DOA for which the change is lower than a predefined threshold.
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Citations
24 Claims
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1. A control method of a wireless communication system comprising first and second communication devices, the second communication device comprising an antenna array, and an array weight vector (hereinafter “
- AWV”
) control circuit that changes at least one of amplitudes and phases of transmission signals or received signals of a plurality of antenna elements included in the antenna array, the control method comprising;when an AWV of at least two antenna elements among the plurality of antenna elements included in the antenna array is independently controlled, (a) receiving, in the second communication device, while scanning a beam direction by changing an AWV of the antenna array of the second communication device, a training signal transmitted from the first communication device by using a fixed beam pattern; (b) determining at least one direction of arrival (DOA) in the second communication device based on reception signal characteristics of the training signal; (c) receiving, in the second communication device, the training signal transmitted by the first communication device while changing the AWV of the antenna array of the second communication device in such a manner that a null direction or a direction close to the null direction is successively pointed to one by one from the at least one DOA; (d) comparing a reception signal characteristic obtained in the step (a) with a reception signal characteristic obtained in the step (c) for each of the at least one DOA, and specifying a DOA for which a ratio or a difference between these reception signal characteristics is smaller than a predefined threshold; (e) obtaining at least one AWV each having a main beam direction or a sub-beam direction close to the main beam pointing to one of the at least one DOA in the second communication device determined in the step (b) except for the DOA specified in the step (d); and (f) using the at least one AWV obtained in the step (e) for communication between the first and second communication devices. - View Dependent Claims (2, 3, 4, 5, 10, 11, 12, 13, 14, 15, 16, 17, 18)
- AWV”
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6. A control method of a wireless communication system comprising first and second communication devices, the second communication device comprising an antenna array, and an array weight vector (AWV) control circuit that changes at least one of amplitudes and phases of transmission signals or received signals of a plurality of antenna elements included in the antenna array, the control method comprising:
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when an AWV of at least two antenna elements among the plurality of antenna elements forming the antenna array is independently controlled, (a) radiating, by the second communication device, a training signal while scanning a beam direction by changing an AWV of the antenna array in a state where the first communication device is performing a receiving operation by using a fixed beam pattern; (b) determining at least one direction of departure (DOD) of the second communication device based on reception signal characteristics of the training signal in the first communication device; (c) radiating, from the second communication device, the training signal while changing the AWV of the antenna array in such a manner that a null direction or a direction close to the null direction is successively pointed to one by one from the at least one DOD in a state where the first communication device is performing a receiving operation by using the fixed beam pattern; (d) comparing a reception signal characteristic of the first communication device obtained in the step (a) with a reception signal characteristic of the first communication device obtained in the step (c) for each of the at least one DOD, and specifying an DOD for which a ratio or a difference between these reception signal characteristics is smaller than a predefined threshold; (e) obtaining at least one AWV each having a main beam direction or a sub-beam direction close to the main beam pointing to one of the at least one DOD of the second communication device determined in the step (b) except for the DOD specified in the step (d); and (f) using the at least one AWV obtained in the step (e) for communication between the first and second communication devices. - View Dependent Claims (7, 8, 9)
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19. A wireless communication system comprising:
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a first communication device configured to be capable of emitting a signal in a fixed beam pattern; and a second communication device comprising an antenna array, and an array weight vector (hereinafter “
AWV”
) control circuit that changes at least one of amplitudes and phases of transmission signals or received signals of a plurality of antenna elements included in the antenna array, whereinthe first and second communication devices are configured to perform an AWV determination process, the AWV determination process comprising; (a) receiving, in the second communication device, while scanning a beam direction by changing an AWV of the antenna array of the second communication device, the training signal transmitted from the first communication device by using the fixed beam pattern; (b) determining at least one direction of arrival (DOA) in the second communication device based on reception signal characteristics of the training signal; (c) receiving, in the second communication device, the training signal transmitted by the first communication device while changing the AWV of the antenna array of the second communication device in such a manner that a null direction or a direction close to the null direction is successively pointed to one by one from the at least one DOA; (d) comparing a reception signal characteristic obtained in the step (a) with a reception signal characteristic obtained in the step (c) for each of the at least one DOA, and specifying a DOA for which a ratio or a difference between these reception signal characteristics is smaller than a predefined threshold; (e) obtaining at least one AWV each having a main beam direction or a sub-beam direction close to the main beam pointing to one of the at least one DOA in the second communication device determined in the step (b) except for the DOA specified in the step (d); and (f) using the at least AWV obtained in the step (e) for communication between the first and second communication devices.
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20. A wireless communication system comprising:
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a first communication device configured to be capable of receiving a signal in fixed beam pattern; and a second communication device comprising an antenna array, and an array weight vector (hereinafter “
AWV”
) control circuit that changes at least one of amplitudes and phases of transmission signals or received signals of a plurality of antenna elements included in the antenna array, whereinthe first and second communication devices are configured to perform an AWV determination process, the AWV determination process comprising; (a) radiating, by the second communication device, a training signal while scanning a beam direction by changing an AWV of the antenna array in a state where the first communication device is performing a receiving operation by using the fixed beam pattern; (b) determining at least one direction of departure (DOD) of the second communication device based on reception signal characteristics of the training signal in the first communication device; (c) radiating, from the second communication device, the training signal while changing the AWV of the antenna array in such a manner that a null direction or a direction close to the null direction is successively pointed to one by one from the at least one DOD in a state where the first communication device is performing a receiving operation by using the fixed beam pattern; (d) comparing a reception signal characteristic of the first communication device obtained in the step (a) with a reception signal characteristic of the first communication device obtained in the step (c) for each of the at least one DOD, and specifying an DOD for which a ratio or a difference between these reception signal characteristics is smaller than a predefined threshold; (e) obtaining at least one AWV each having a main beam direction or a sub-beam direction close to the main beam pointing to one of the at least one DOD of the second communication device determined in the step (b) except for the DOD specified in the step (d); and (f) using the AWV obtained in the step (e) for communication between the first and second communication devices.
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21. A wireless communication device comprising:
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an antenna array; an array weight vector (AWV) control unit that changes amplitudes and phases of received signals of a plurality of antenna elements included in the antenna array; a receiving unit that performs a process for the received signals; and a processing unit that determines an AWV used for wireless communication with a corresponding device, and supplies the determined AWV to the control unit, wherein the processing unit performs; (a) determining at least one direction of arrival (DOA) based on reception signal characteristics obtained by receiving a training signal transmitted from the corresponding device at the receiving unit while scanning a beam direction by changing an AWV of the antenna array; (b) comparing a reception signal characteristic obtained by receiving the training signal at the receiving unit while changing the AWV of the antenna array in such a manner that a null direction or a direction close to the null direction is successively pointed to one by one from the at least one DOA, with the reception signal characteristic obtained in the step (a), and specifying an DOA for which a ratio or a difference between these reception signal characteristics is smaller than a predefined threshold; and (c) obtaining at least one AWV each having a main beam direction or a sub-beam direction close to the main beam pointing to one of the at least one DOA determined in the step (a) except for the DOA specified in the step (b).
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22. A wireless communication device comprising:
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an antenna array; an array weight vector (AWV) control unit that changes amplitudes and phases of transmission signals of a plurality of antenna elements included in the antenna array; and a processing unit that determines an AWV used for wireless communication with a corresponding device, and supplies the determined AWV to the control unit, wherein the processing unit performs; (a) determining at least one direction of departure (DOD) based on reception signal characteristics of a training signal in the corresponding device, the reception signal characteristics being obtained by radiating the training signal while scanning a beam direction by changing an AWV of the antenna array; (b) comparing a reception signal characteristic of the training signal in the corresponding device obtained by radiating the training signal while changing the AWV of the antenna array in such a manner that a null direction or a direction close to the null direction is successively pointed to one by one from the at least one DOD, with the reception signal characteristic obtained in the step (a), and specifying a DOD for which a ratio or a difference between these reception signal characteristics is smaller than a predefined threshold; and (c) obtaining at least one AWV having a main beam direction or a sub-beam direction close to the main beam pointing to one of the at least one DOD determined in the step (a) except for the DOD specified in the step (b).
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23. An array weight vector (hereinafter “
- AWV”
) adjustment method of a wireless communication device comprising an antenna array, and an AWV control unit that changes amplitudes and phases of received signals of a plurality of antenna elements included in the antenna array, the AWV adjustment method comprising;(a) receiving, while scanning a beam direction by changing an AWV of the antenna array, a training signal transmitted from a corresponding device; (b) determining at least one direction of arrival (DOA) based on reception signal characteristics of the training signal; (c) comparing a reception signal characteristic obtained by receiving the training signal while changing the AWV of the antenna array in such a manner that a null direction or a direction close to the null direction is successively pointed to one by one from the at least one DOA, with the reception signal characteristic obtained in the step (a), and specifying an DOA for which a ratio or a difference between these reception signal characteristics is smaller than a predefined threshold; (d) obtaining at least one AWV having a main beam or a sub-beam direction close to the main beam pointing to one of the at least one DOA determined in the step (b) except for the DOA specified in the step (c); and (e) using the at least one AWV obtained in the step (d) for wireless communication with the corresponding device.
- AWV”
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24. An array weight vector (hereinafter “
- AWV”
) adjustment method of a wireless communication device comprising an antenna array, and an AWV control unit that changes amplitudes and phases of transmission signals of a plurality of antenna elements included in the antenna array, the AWV adjustment method comprising;(a) radiating a training signal while scanning a beam direction by changing an AWV of the antenna array; (b) determining at least one direction of departure (DOD) based on reception signal characteristics of the training signal obtained in a corresponding device; (c) comparing a reception signal characteristic of the training signal in the corresponding device obtained by radiating the training signal while changing the AWV of the antenna array in such a manner that a null direction or a direction close to the null direction is successively pointed to one by one from the at least one DOD, with the reception signal characteristic obtained in the step (a), and specifying a DOD for which a ratio or a difference between these reception signal characteristics is smaller than a predefined threshold; (d) obtaining at least one AWV having a main beam direction or a sub-beam direction close to the main beam pointing to one of the at least one DOD determined in the step (b) except for the DOD specified in the step (c); and (e) using the at least one AWV obtained in the step (d) for wireless communication with the corresponding device.
- AWV”
Specification