Communication system
First Claim
1. A communication system comprising:
- a transmitter having a signal input means for receiving a signal, a modulating means for producing m signal points, where m is an integer not less than 4, in a signal space diagram through modulation of a carrier wave using an input signal fed from the signal input means, and a transmitting means for transmitting a modulated signal, in which the main procedure includes receiving the input signal containing a first data stream of n values and a second data stream, dividing the m signal points into n signal point groups, assigning n values of the first data stream to the n signal point groups respectively, assigning data of the second data stream to the signal points of each signal point group, and encoding said first and/or second data streams in a Trellis encoder.
1 Assignment
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Accused Products
Abstract
At the transmitter sid , carri r waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rat between first and second data streams is developed by shifting the signal points to other positions in the space diagram. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into, low and high, frequency band components which ar designated as a first and a second data stream respectively. Upon receiving the TV signal, a receiver can reproduce only the low frequency band component or both the low and high frequency band components, depending on its capability.
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Citations
38 Claims
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1. A communication system comprising:
a transmitter having a signal input means for receiving a signal, a modulating means for producing m signal points, where m is an integer not less than 4, in a signal space diagram through modulation of a carrier wave using an input signal fed from the signal input means, and a transmitting means for transmitting a modulated signal, in which the main procedure includes receiving the input signal containing a first data stream of n values and a second data stream, dividing the m signal points into n signal point groups, assigning n values of the first data stream to the n signal point groups respectively, assigning data of the second data stream to the signal points of each signal point group, and encoding said first and/or second data streams in a Trellis encoder. - View Dependent Claims (4, 7, 8, 9, 37)
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2. A communication system comprising:
a receiver having a signal input means for receiving a modulated signal, a demodulating means for demodulating a received QAM signal representing P signal points in a signal space diagram, and an output means for outputting a demodulated signal, in which the main procedure includes dividing the P signal points into n signal point groups, demodulating a first data stream of which n values are assigned to the n signal point groups, demodulating a second data stream of which P/n values are assigned to P/n signal points of each signal point group for reconstruction of data of th first and s cond data str am, and d coding said first and/or second data streams in a Tr llis decoder. - View Dependent Claims (5, 10, 11, 12, 38)
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3. A communication system comprising:
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a transmitter having a signal input circuit, a modulator circuit for producing m (m≧
4) signal points in a signal space diagram through modulation of a carrier wave using an input signal fed from the signal input circuit, and a transmitter circuit for transmitting a modulated signal, in which a main procedure includes receiving the input signal containing a first data stream of n values and a second data stream, dividing the m signal points into n signal point groups, assigning n values of the first data stream to the n signal point groups respectively, assigning data of the second data stream to the signal points of each signal point group, and encoding at least one of said first and second data streams by a Trellis encoder; and
a receiver having an input circuit for reception of said modulated signal transmitted from the transmitter, a demodulator circuit for demodulating a QAM modulated multi-level signal representing P signal points in a signal space diagram, and an output circuit, in which the main procedure includes dividing the P signal points into signal point groups, demodulating the first data stream of which n values are assigned to the n signal point groups, demodulating the second data stream of which P/n values are assigned to P/n signal points of each signal point group for reconstruction of data of the first and second data streams, and decoding at least one of said first and second data streams in a Tr his decoder. - View Dependent Claims (6)
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13. A recording/playback system comprising:
a recording means having a signal input means for receiving a signal, a modulating means for producing m signal points, where m is an integer not less than 4, in a signal space diagram through modulation of a carrier wave using an input signal fed from the signal input means, and a recording means for recording a modulated signal on a recording medium, in which the main procedure includes receiving the input signal containing a first data stream of n values and a second data stream, dividing the m signal points into n signal point groups, assigning n values of the first data stream to the n signal point groups respectively, and assigning data of the second data stream to the signal points of each signal point group. - View Dependent Claims (16, 19, 20, 21)
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14. A recording/playback system comprising:
a playback means having a signal reproducing means for reproducing a recorded signal from a recording medium, a demodulating means for demodulating a received QAM signal representing P signal points in a signal space diagram, and an output means for outputting a demodulated signal, in which the main procedure includes dividing the P signal points into n signal point groups, demodulating a first data stream of which n values are assigned to the n signal point groups, and demodulating a second data stream of which P/n values are assigned to P/n signal points of each signal point group for reconstruction of data of the first and second data stream. - View Dependent Claims (17, 22, 23, 24)
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15. A recording/playback system comprising:
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a recorder having a signal input circuit, a modulator circuit for producing m (m≧
4) signal points in a signal space diagram through modulation of a carrier wave using an input signal fed from the signal input circuit, and a recording circuit for recording a modulated signal on a recording medium, in which a main procedure includes receiving th input signal containing a first data stream of n values and a second data stream, dividing the m signal points into n signal point groups, and assigning n values of the first data stream to the n signal point groups respectively, assigning data of the second data stream to the signal points of each signal point group; and
a playback unit having a signal reproducing circuit for reproducing a recorded signal from said recording medium, a demodulating circuit for demodulating a received QAM signal representing P signal points in a signal space diagram, and an output circuit for outputting a demodulated signal, in which the main procedure includes dividing the P signal points into n signal point groups, demodulating a first data stream of which n values are assigned to the n signal point groups, and demodulating a second data stream of which P/n values are assigned to P/n signal points of each signal point group for reconstruction of data of the first and second data stream. - View Dependent Claims (18)
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25. A communication system comprising:
a transmitter of OFDM type in which an input signal is serial to parallel converted into a plurality of input signals and then transmitted through modulation in a plurality of modulators whose carrier waves are 90°
-out-of-phase with each other, each of said modulators having a signal input means for receiving an input signal, a modulating means for producing m signal points, where m is an integer not less than 4, in a signal space diagram through modulation of said carrier wave using an input signal fed from the signal input means, and a transmitting means for transmitting a modulated signal, in which the main procedur includes receiving the input signal containing a first data stream of n values and a second data stream, dividing the m signal points into n signal point groups, assigning n values of the first data stream to the n signal point groups respectively, and assigning data of the second data stream to the signal points of each signal point group.- View Dependent Claims (28, 31, 32, 33)
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26. A communication system comprising:
a receiver having a signal input means for converting a modulated signal into a plurality of carrier waves in an FFT converter, a demodulating means for demodulating a received QAM signal representing P signal points in a signal space diagram, and an output means for outputting a demodulated signal, in which the main procedure includes dividing the P signal points into n signal point groups, demodulating a first data stream of which n values are assigned to the n signal point groups, and demodulating a second data stream of which P/n values are assigned to P/n signal points of each signal point group for reconstruction of data of the first and second data stream. - View Dependent Claims (29, 34, 35, 36)
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27. A communication system comprising:
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a transmitter of OFDM type in which an input signal is serial to parallel converted into a plurality of input signals and then transmitted through modulation in a plurality of modulators whose carrier waves are 90°
-out-of-phase with each oth r, each of said modulators having a signal input circuit for receiving an input signal, a modulating circuit for producing m (m≧
4) signal points in a signal space diagram through modulation of said carrier wave using an input signal fed from the signal input circuit, and a transmitting circuit for transmitting a modulated signal, in which the main procedure includes receiving the input signal containing a first data stream of n values and a second data stream, dividing the m signal points into n signal point groups, assigning n values of the first data stream to the n signal point groups respectively, and assigning data of the second data stream to the signal points of each signal point group; and
a receiver having a signal input circuit for converting said modulated signal transmitted from said transmitting circuit into a plurality of carrier waves in an FFT converter, a demodulating circuit for demodulating a received QAM signal representing P signal points in a signal space diagram, and an output circuit for outputting a demodulated signal, in which the main procedure includes dividing the P signal points into n signal point groups, demodulating a first data stream of which n values are assigned to th n signal point groups, and demodulating a second data stream of which P/n values are assigned to P/n signal points of each signal point group for reconstruction of data of the first and second data stream. - View Dependent Claims (30)
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Specification