Orthogonal frequency division multiplex modem circuit
First Claim
1. An orthogonal frequency division multiplex modem system which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, wherein one or more of said plurality of subcarriers are assigned to each one of said plurality of communication channels, said system comprising:
- in a transmission side thereof, a randomizer which randomly changes the order of the sequence of the alignment of said plurality of subcarriers on a frequency axis.
1 Assignment
0 Petitions
Accused Products
Abstract
To provide an orthogonal frequency division multiplex modem circuit which can multiplex signals, whose bit rates and QoS are different from one another, and can transmit the signals via one OFDM line. A serial/parallel converter converts input signals into a complex parallel signal respectively, and a sub carrier and a modulation system are assigned every communication channel. A randomizer changes the alignment sequence of the signal, a discrete inverse Fourier transformer processes the signal, a parallel/serial converter converts the signal into a serial signal, and a transmitter performs the orthogonal modulation of the signal to output the signal from an antenna. A receiver performs orthogonal demodulation of the signal received with an antenna, a serial/parallel converter converts the signal into a parallel signal, and a discrete Fourier transformer processes the parallel signal. In addition, a de-randomizer restores the alignment sequence of the subcarriers into the original condition, and a parallel/serial converter decodes and outputs the signal.
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Citations
42 Claims
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1. An orthogonal frequency division multiplex modem system which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, wherein one or more of said plurality of subcarriers are assigned to each one of said plurality of communication channels, said system comprising:
- in a transmission side thereof, a randomizer which randomly changes the order of the sequence of the alignment of said plurality of subcarriers on a frequency axis.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- 11. An transmission system of an orthogonal frequency division multiplex modem system which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, wherein one or more subcarriers are assigned to each of a plurality of the communication channels, and a randomizer which randomly changes the order of the sequence of the alignment of subcarriers on a frequency axis is included.
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19. A receiving system of an orthogonal frequency division multiplex modem system which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, the receiving system comprising:
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a receiver for receiving a signal from an orthogonal frequency division multiplex modulator transmitting a plural of communication channels; a demodulator for demodulating the signal; and a de-randomizer which restores the alignment of subcarriers to the order of sequence of the alignment before it is randomly changed in a transmitting side.
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20. An orthogonal frequency division multiplex communication method that uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, the communication method comprising the steps of:
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assigning one or more subcarriers to each of a plurality of communication channels; changing randomly, the order of the sequence of the alignment of subcarriers on a frequency axis; and restoring the alignment of subcarriers to the order of sequence of the alignment before it is changed. - View Dependent Claims (21, 22, 23, 24, 25)
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26. An orthogonal frequency division multiplex transmission method which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, the transmission method comprises the steps of:
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assigning one or more subcarriers to each of a plurality of the communication channels; changing randomly the order of the sequence of the alignment of subcarriers on a frequency axis. - View Dependent Claims (27, 28, 29, 30, 31)
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32. An orthogonal frequency division multiplex receiving method which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, the receiving method comprising the steps of:
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receiving a signal from an orthogonal frequency division multiplex modulator transmitting a plural of communication channels; demodulating the signal; and restoring the alignment of subcarriers to the order of sequence of the alignment before it is randomly changed in a transmitting side.
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- 33. An orthogonal frequency division multiplex modem system which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, wherein one or more subcarriers are assigned to each of a plurality of communication channels, the modem system comprising a randomizer which randomly assigns subcarriers to each communication channel.
- 35. A transmission system of an orthogonal frequency division multiplex modem system which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, wherein one or more subcarriers are assigned to each of a plurality of the communication channels, the transmission system comprising a randomizer which randomly assigns subcarriers to each communication channel.
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37. A receiving system of an orthogonal frequency division multiplex modem system which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, the receiving system comprising:
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a receiver for receiving a signal from an orthogonal frequency division multiplex modulator transmitting a plural of communication channels; a demodulator for demodulating the signal; and a de-randomizer which restores the sequence of the subcarriers randomly changed in a transmitting side.
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38. An orthogonal frequency division multiplex communication method that uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, the communication method comprising the steps of:
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randomly assigning one or more subcarriers to each of a plurality of communication channels; and restoring the sequence of the subcarriers randomly changed in a transmitting side. - View Dependent Claims (39)
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- 40. An orthogonal frequency division multiplex transmission method which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, the transmission method comprises randomly assigning one or more subcarriers to each of a plurality of the communication channels.
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42. An orthogonal frequency division multiplex receiving method which uses a plurality of subcarriers for communication and transmits and receives a plurality of communication channels, the receiving method comprising:
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receiving a signal from an orthogonal frequency division multiplex modulator transmitting a plural of communication channels; demodulating the signal; and restoring the sequence of the subcarriers randomly changed in a transmitting side.
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Specification