Communication system

• US 6,549,716 B1
• Filed: 02/16/2000
• Issued: 04/15/2003
• Est. Priority Date: 03/26/1992
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Oshima, Mitsuaki
• Primary Examiner(s): Chevalier, Robert
• Application Number:
  US09/505,753
• Time in Patent Office: 1,154 Days
• Field of Search: H04/N.708, H04/N.7081, 386/46, 386/92, 386/95, 386/1, 386/123, 348/6, 348/17, 348/21, 348/725, 348/726, 348/723, 348/724, 360/32
• US Class Current: 386/241
• CPC Class Codes: H03M 13/256 with trellis coding, e.g. with convolutional codes and TCM
• CPC Class Codes: H03M 13/35 Unequal or adaptive error protection, e.g. by providing a different level of protection according to significance of source information or by adapting the coding according to the change of transmission channel characteristics
• CPC Class Codes: H04L 1/0042 Encoding specially adapted to other signal generation operation, e.g. in order to reduce transmit distortions, jitter, or to improve signal shape H04L1/0067 takes precedence
• CPC Class Codes: H04L 1/0047 Decoding adapted to other signal detection operation in conjunction with sequence estimation or equalization H04L25/03286
• CPC Class Codes: H04L 1/0054 Maximum-likelihood or sequential decoding, e.g. Viterbi, Fano, ZJ algorithms
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/006 Trellis-coded modulation
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 1/007 Unequal error protection for format H04L1/0078; for codes per se H03M13/35
• CPC Class Codes: H04L 27/02 Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation H04L27/32 takes precedence
• CPC Class Codes: H04L 27/04 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/183 Multiresolution systems
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2604 Multiresolution systems by means of multiresolution subcarriers H04L27/183, H04L27/3488
• CPC Class Codes: H04L 27/2627 Modulators
• CPC Class Codes: H04L 27/2649 Demodulators
• CPC Class Codes: H04L 27/3488 Multiresolution systems
• CPC Class Codes: H04L 27/3854 using a non - coherent carrier, including systems with baseband correction for phase or frequency offset
• CPC Class Codes: H04N 19/30 using hierarchical techniques, e.g. scalability H04N19/63 takes precedence
• CPC Class Codes: H04N 19/37 : with arrangements for assigning different transmission priorities to video input data or to video coded data
• CPC Class Codes: H04N 19/60 : using transform coding
• CPC Class Codes: H04N 19/63 : using sub-band based transform, e.g. wavelets
• CPC Class Codes: H04N 21/234327 : by decomposing into layers, e.g. base layer and one or more enhancement layers
• CPC Class Codes: H04N 21/2365 : Multiplexing of several video streams
• CPC Class Codes: H04N 21/2383 : Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/426 : Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/4347 : Demultiplexing of several video streams
• CPC Class Codes: H04N 21/4382 : Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/440227 : by decomposing into layers, e.g. base layer and one or more enhancement layers
• CPC Class Codes: H04N 21/631 : Multimode Transmission, e.g. transmitting basic layers and enhancement layers of the content over different transmission paths or transmitting with different error corrections, different keys or with different transmission protocols
• CPC Class Codes: H04N 5/455 : Demodulation-circuits
• CPC Class Codes: H04N 5/46 : for receiving on more than one standard at will deflecting circuits of multi-standard receivers H04N3/27
• CPC Class Codes: H04N 7/015 : High-definition television systems
• CPC Class Codes: H04N 7/24 : Systems for the transmission of television signals using pulse code modulation H04N21/00 takes precedence

Abstract

At the transmitter side, carrier 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 rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal.

Claims

1. A signal transmission apparatus for transmitting a plurality of data streams, including at least a first data stream and a second data stream, said signal transmission apparatus comprising:

a VSB modulator operable to modulate the first data stream to an n-level VSB modulated signal and the second data stream to an 8-level VSB modulated signal, wherein n is an integer and n is less than 8, and

a transmitter operable to transmit the n-level VSB modulated signal and the 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal.

2. A signal receiving apparatus for reconstructing a plurality of data streams including at least a first data stream and a second data stream, said signal receiving apparatus comprising:

a receiving unit operable to receive an n-level VSB modulated signal and an 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal, and

a VSB demodulator operable to demodulate the n-level VSB modulated signal to the first data stream and demodulating the 8-level VSB modulated signal to the second data stream, wherein n is an integer and n is less than 8.

3. A signal transmission and receiving system comprising:

a signal transmission apparatus operable to transmit a plurality of data streams, including at least a first data stream and a second data stream, said signal transmission apparatus comprising

a VSB modulator operable to modulate the first data stream to an n-level VSB modulated signal and the second data stream to an 8-level VSB modulated signal, wherein n is an integer and n is less than 8, and

a transmitter operable to transmit the n-level VSB modulated signal and the 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal; and

a signal receiving apparatus operable to reconstruct the plurality of data streams including at least the first data stream and the second data stream, said signal receiving apparatus comprising

a receiving unit operable to receive the n-level VSB modulated signal and the 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal, and

a VSB demodulator operable to demodulate the n-level VSB modulated signal to the first data stream and demodulating the 8-level VSB modulated signal to the second data stream, wherein n is an integer and n is less than 8.

4. A signal transmission method for transmitting a plurality of data streams, including at least a first data stream and a second data stream, said signal transmission method comprising:

modulating the first data stream to an n-level VSB modulated signal and the second data stream to an 8-level VSB modulated signal, wherein n is an integer and n is less than 8, and

transmitting the n-level VSB modulated signal and the 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal.

5. A signal receiving method for reconstructing a plurality of data streams including at least a first data stream and a second data stream, said signal receiving method comprising:

receiving an n-level VSB modulated signal and an 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal, and

demodulating the n-level VSB modulated signal to the first data stream and demodulating the 8-level VSB modulated signal to the second data stream, wherein n is an integer and n is less the 8.

6. A signal transmission and receiving method comprising:

a signal transmission method for transmitting a plurality of data streams, including at least a first data stream and a second data stream, said signal transmission method comprising

modulating the first data stream to an n-level VSB modulated signal and the second data stream to an 8-level VSB modulated signal, wherein n is an integer and n is less than 8, and

transmitting the n-level VSB modulated signal and the 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal; and

a signal receiving method for reconstructing the plurality of data streams including at least the first data stream and the second data stream, said signal receiving method comprising

receiving the n-level VSB modulated signal and the 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal, and

demodulating the n-level VSB modulated signal to the first data stream and demodulating the 8-level VSB modulated signal to the second data stream, wherein n is an integer and n is less then 8.

7. A signal transmission apparatus for transmitting a plurality of data streams, including at least a first data stream and a second data stream, said signal transmission apparatus comprising:

an ASK modulator operable to modulate the first data stream to an n-level ASK modulated signal and the second data stream to an 8-level ASK modulated signal, wherein n is an integer and n is less than 8,

a filter operable to filter the n-level ASK modulated signal and the 8-level ASK modulated signal to produce an n-level VSB modulated signal and an 8-level VSB modulated signal; and

a transmitter operable to transmit the n-level VSB modulated signal and the 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal.

8. A signal receiving apparatus for reconstructing a plurality of data streams including at least a first data stream and a second data stream, said signal receiving apparatus comprising:

a receiving unit operable to receive an n-level VSB modulated signal and an 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal,

a filter operable to filter the received n-level VSB modulated signal and the received 8-level VSB modulated signal, and

a VSB demodulator operable to demodulate the filtered n-level VSB modulated signal to the first data stream and demodulating the filtered 8-level VSB modulated signal to the second data stream, wherein n is an integer and n is less than 8.

9. A signal transmission and receiving system comprising:

a signal transmission apparatus operable to transmit a plurality of data streams, including at least a first data stream and a second data stream, said signal transmission apparatus comprising

an ASK modulator operable to modulate the first data stream to an n-level ASK modulated signal and the second data stream to an 8-level ASK modulated signal, wherein n is an integer and n is less than 8,

a filter operable to filter the n-level ASK modulated signal and the 8-level ASK modulated signal to produce an n-level VSB modulated signal and an 8-level VSB modulated signal, and

a transmitter operable to transmit the n-level VSB modulated signal and the 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal; and

a signal receiving apparatus operable to reconstruct the plurality of data streams including at least the first data stream and the second data stream, said signal receiving apparatus comprising

a receiving unit operable to receive the n-level VSB modulated signal and the 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal,

a filter operable to filter the received n-level VSB modulated signal and the received 8-level VSB modulated signal, and

a VSB demodulator operable to demodulate the filtered n-level VSB modulated signal to the first data stream and demodulating the filtered 8-level VSB modulated signal to the second data stream, wherein n is and integer and n is less than 8.

10. A signal transmission method for transmitting a plurality of data streams, including at least a first data stream and a second data stream, said signal transmission method comprising:

modulating the first data stream to an n-level ASK modulated signal and the second data stream to an 8-level ASK modulated signal, wherein n is an integer and n is less than 8,

filtering the n-level ASK modulated signal and the 8-level ASK modulated signal to produce an n-level VSB modulated signal and an 8-level VSB modulated signal; and

transmitting the n-level VSB modulated signal and the 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal.

11. A signal receiving method for reconstructing a plurality of data streams including at least a first data stream and a second data stream, said signal receiving method comprising:

receiving an n-level VSB modulated signal and an 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal,

filtering the received n-level VSB modulated signal and the received 8-level VSB modulated signal, and

demodulating the filtered n-level VSB modulated signal to the first data stream and demodulating the filtered 8-level VSB modulated signal to the second data stream, wherein n is an integer and n is less than 8.

12. A signal transmission and receiving method comprising:

a signal transmission method for transmitting a plurality of data streams, including at least a first data stream and a second data stream, said signal transmission method comprising

assigning the first data stream to an n-level ASK modulated signal and the second data stream to an 8-level ASK modulated signal, wherein n is an integer and n is less the 8,

filtering the n-level ASK modulated signal and the 8-level ASK modulated signal to produce an n-level VSB modulated signal and an 8-level VSB modulated signal; and

transmitting the n-level VSB modulated signal and the 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal; and

a signal receiving method for reconstructing the plurality of data streams including at least the first data stream and the second data stream, said signal receiving apparatus comprising

receiving the n-level VSB modulated signal and the 8-level VSB modulated signal under a condition where the transmission power of the n-level VSB modulated signal is larger than the transmission power of the 8-level VSB modulated signal,

filtering the received n-level VSB modulated signal and the received 8-level VSB modulated signal, and

demodulating the filtered n-level VSB modulated signal to the first data stream and demodulating the filtered 8-level VSB modulated signal to the second data stream, wherein n is an integer and n is less than 8.