Communication apparatus performing key feature extraction for cognitive radio system
First Claim
1. A communication apparatus, comprising:
- an extraction unit configured to extract a reception key feature of a temporal change in received power in each frequency band contained in a received signal;
a storage unit configured to store, in correspondence with one another, a system name of at least one system which uses the frequency band, event information indicating that a communication apparatus belonging to the system starts or stops transmission, and at least one transmission key feature of a temporal waveform change shape of a transmission signal from a communication apparatus belonging to the system, at least one transmission key feature corresponding to the event information;
a determination unit configured to determine whether there is any transmission key feature matching the reception key feature, by comparing the reception key feature with the transmission key feature; and
a selection unit configured to select, when the determination unit determines that there is a matched transmission key feature, the event information and the system name which correspond to the transmission key feature from the storage unit, whereinthe extraction unit extracts a derivative of a temporal waveform change shape of the received power as the reception key feature,the storage unit stores a threshold corresponding to the temporal waveform change shape of the transmission signal corresponding to the event information, andthe determination unit compares the extracted derivative with the stored threshold with reference to signs and magnitudes, and determines that key features match, if a sign of the extracted derivative equals to a sign of the stored threshold match and a magnitude of the extracted derivative is larger than a magnitude of the stored threshold.
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Abstract
A communication apparatus, includes unit extracting a reception key feature of a temporal change in received power in each frequency band contained in a received signal, unit storing, in correspondence with one another, a system name of a system which uses the frequency band, event information indicating that a communication apparatus belonging to the system starts or stops transmission, and a transmission key feature of a temporal waveform change shape of a transmission signal from a communication apparatus belonging to the system, a transmission key feature corresponding to the event information, unit determining whether there is any transmission key feature matching the reception key feature, by comparing the reception key feature with the transmission key feature, and unit selecting, when the determination unit determines that there is a matched transmission key feature, the event information and the system name which correspond to the transmission key feature from the storage unit.
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Citations
16 Claims
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1. A communication apparatus, comprising:
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an extraction unit configured to extract a reception key feature of a temporal change in received power in each frequency band contained in a received signal; a storage unit configured to store, in correspondence with one another, a system name of at least one system which uses the frequency band, event information indicating that a communication apparatus belonging to the system starts or stops transmission, and at least one transmission key feature of a temporal waveform change shape of a transmission signal from a communication apparatus belonging to the system, at least one transmission key feature corresponding to the event information; a determination unit configured to determine whether there is any transmission key feature matching the reception key feature, by comparing the reception key feature with the transmission key feature; and a selection unit configured to select, when the determination unit determines that there is a matched transmission key feature, the event information and the system name which correspond to the transmission key feature from the storage unit, wherein the extraction unit extracts a derivative of a temporal waveform change shape of the received power as the reception key feature, the storage unit stores a threshold corresponding to the temporal waveform change shape of the transmission signal corresponding to the event information, and the determination unit compares the extracted derivative with the stored threshold with reference to signs and magnitudes, and determines that key features match, if a sign of the extracted derivative equals to a sign of the stored threshold match and a magnitude of the extracted derivative is larger than a magnitude of the stored threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A communication apparatus, comprising:
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an extraction unit configured to extract a reception key feature of a temporal change in received power in each frequency band contained in a received signal; a storage unit configured to store, in correspondence with one another, a system name of at least one system which uses the frequency band, event information indicating that a communication apparatus belonging to the system starts or stops transmission, and at least one transmission key feature of a temporal waveform change shape of a transmission signal from a communication apparatus belonging to the system, at least one transmission key feature corresponding to the event information; a determination unit configured to determine whether there is any transmission key feature matching the reception key feature, by comparing the reception key feature with the transmission key feature; and a selection unit configured to select, when the determination unit determines that there is a matched transmission key feature, the event information and the system name which correspond to the transmission key feature from the storage unit, wherein the extraction unit includes; a calculation unit configured to extract a slow change in key feature measured during a predetermined past period of time from a current point of time in a given frequency band; a prediction unit configured to predict a change in key feature after a lapse of a predetermined period of time on the basis of the extracted slow change; and a correction unit configured to generate a corrected key feature by correcting the reception key feature by subtracting the predicted change from the reception key feature detected at a time corresponding to the lapse of the predetermined period of time, and wherein the determination unit compares the corrected key feature with the transmission key feature.
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13. A communication apparatus, comprising:
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an extraction unit configured to extract a reception key feature of a temporal change in received power in each frequency band contained in a received signal; a storage unit configured to store, in correspondence with one another, a system name of at least one system which uses the frequency band, event information indicating that a communication apparatus belonging to the system starts or stops transmission, and at least one transmission key feature of a temporal waveform change shape of a transmission signal from a communication apparatus belonging to the system, at least one transmission key feature corresponding to the event information; a determination unit configured to determine whether there is any transmission key feature matching the reception key feature, by comparing the reception key feature with the transmission key feature; a selection unit configured to select, when the determination unit determines that there is a matched transmission key feature, the event information and the system name which correspond to the transmission key feature from the storage unit; an instructing unit configured to generate an instruction to change a likelihood used for error correction decoding; and a decoding unit configured to perform error correction decoding after changing a likelihood in accordance with the instruction, and wherein if it is determined that the reception key feature extracted in a second frequency band matches a key feature of a temporal waveform change shape of a transmission signal when a communication apparatus of another system which uses each frequency band which a communication apparatus belonging to a self system receives starts transmission, the instructing unit decreases a likelihood corresponding to a time slot including a time when it is determined that the key feature of the signal matches the key feature of a signal received in the second frequency band.
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14. A communication apparatus, comprising:
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an extraction unit configured to extract a reception key feature of a temporal change in received power in each frequency band contained in a received signal; a storage unit configured to store, in correspondence with one another, a system name of at least one system which uses the frequency band, event information indicating that a communication apparatus belonging to the system starts or stops transmission, and at least one transmission key feature of a temporal waveform change shape of a transmission signal from a communication apparatus belonging to the system, at least one transmission key feature corresponding to the event information; a determination unit configured to determine whether there is any transmission key feature matching the reception key feature, by comparing the reception key feature with the transmission key feature; a selection unit configured to select, when the determination unit determines that there is a matched transmission key feature, the event information and the system name which correspond to the transmission key feature from the storage unit; a requesting unit configured to issue a retransmission request to a communication apparatus belonging to a self system for each block constituting the signal; a correction unit configured to perform error correction of the signal; and a block selection unit configured to select a block for which a retransmission request is to be issued, on the basis of an error correction result obtained by the correction unit and event information and a system which are selected by the selection unit, and wherein the requesting unit issues a retransmission request for the block for which the retransmission request is to be issued. - View Dependent Claims (15, 16)
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Specification