MULTI-CARRIER COMMUNICATION APPARATUS, POWER LINE COMMUNICATION CIRCUIT, AND MULTI-CARRIER COMMUNICATION METHOD
First Claim
1. A multi-carrier communication apparatus which receives a multi-carrier signal from one multi-carrier communication apparatuses via a transmission line, the multi-carrier communication apparatus comprising:
- a complex signal-transformer which transforms a time-domain signal received via the transmission line into at least three complex signals, each of the three complex signals being corresponding to frequency different from each other;
a phase difference-calculator which calculates a phase difference between a pair of the complex signals among the at least three complex signals, the pair of the complex signals being not adjacent to each other on a frequency domain; and
a multi-carrier signal-determining unit which determines, on the basis of the phase difference, whether the time-domain signal is the multi-carrier signal.
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Accused Products
Abstract
Provided is a multi-carrier communication apparatus, power line communication circuit, and multi-carrier communication method capable of decreasing omission of carrier detection even when a plurality of communication apparatuses are simultaneously transmitting signals at the state of time discord. Digital signals transmitted from a digital signal-processing unit 1 are converted into analog signals by an analog circuit unit 2 and then transmitted from a pair of lines 61 and 62 via a communication transformer 3. The digital signal-processing unit 1 has a frequency carrier detecting unit 10 which detects the existence of a carrier on the basis of a frequency characteristic of the received signal and the frequency carrier detecting unit 10 detects the carrier by taking correlation between sub-carriers adjacent to each other at every other interval.
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Citations
16 Claims
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1. A multi-carrier communication apparatus which receives a multi-carrier signal from one multi-carrier communication apparatuses via a transmission line, the multi-carrier communication apparatus comprising:
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a complex signal-transformer which transforms a time-domain signal received via the transmission line into at least three complex signals, each of the three complex signals being corresponding to frequency different from each other;
a phase difference-calculator which calculates a phase difference between a pair of the complex signals among the at least three complex signals, the pair of the complex signals being not adjacent to each other on a frequency domain; and
a multi-carrier signal-determining unit which determines, on the basis of the phase difference, whether the time-domain signal is the multi-carrier signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A multi-carrier communication apparatus which receives a multi-carrier signal from one multi-carrier communication apparatuses via a transmission line, the multi-carrier communication apparatus comprising:
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a complex signal-transformer which transforms a time domain signal received via the transmission line into a first complex signal corresponding to a first frequency, a second complex signal corresponding to a second frequency, and a third complex signal corresponding to a third complex signal, where the third frequency is higher than the second frequency and the second frequency is higher than the first frequency, and the first complex signal has a first phase and the third complex signal has a third phase;
a phase difference-calculator which calculates a phase difference between the first phase and the third phase; and
a multi-carrier signal-determining unit which determines, on the basis of the phase difference, whether the time signal is the multi-carrier signal.
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15. A power line communication circuit which performs communication by using a power line, comprising:
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a coupler separating a communication signal from an alternating voltage of the power line;
a filter block which is connected to the coupler and to which the communication signal separated by the coupler is inputted;
an AD converter which is connected to the filter block and converts the communication signal passed through the filter block into a digital signal, wherein the filter block has a plurality of high-pass filters having mutually different cutoff frequencies, a plurality of low-pass filters having mutually different cutoff frequencies, a selector passing the communication signal separated by the coupler, selecting at least one high-pass filter and one low-pass filter among the plurality of high-pass filters and the plurality of low-pass filters.
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16. A multi-carrier communication method of receiving a multi-carrier signal from one multi-carrier communication apparatuses via a transmission line, the method comprising the steps of:
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transforming a time domain signal received via the transmission line into three or more complex signals, each of the three complex signals being corresponding to frequency different from each other;
calculating a phase difference between a pair of the complex signals, the pair of the complex signals being not adjacent to each other on a frequency domain; and
determining, on the basis of the phase difference, whether the time domain signals is the multi-carrier signal.
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Specification