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Communication system |
| RE40779 |
Communication system
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| Patent Drawings: | |
| Inventor: |
Oshima, et al. |
| Date Issued: |
June 23, 2009 |
| Application: |
10/782,411 |
| Filed: |
February 20, 2004 |
| Inventors: |
Oshima; Mitsuaki (Kyoto, JP)
Sakashita; Seiji (Osaka, JP)
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| Assignee: |
Panasonic Corporation (Osaka, JP) |
| Primary Examiner: |
Ha; Dac V. |
| Assistant Examiner: |
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| Attorney Or Agent: |
Wenderoth, Lind & Ponack, L.L.P. |
| U.S. Class: |
375/261; 375/265; 375/270; 375/277; 375/301; 375/321; 375/340 |
| Field Of Search: |
375/261; 375/265; 375/270; 375/277; 375/285; 375/296; 375/298; 375/301; 375/321; 375/324; 375/340 |
| International Class: |
H04L 5/16 |
| U.S Patent Documents: |
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| Foreign Patent Documents: |
2095435; 1499725; 2627574; 1569334; 0031193; 0122805; 0282298; 0311188; 0329158; 0365431; 0392538; 0448492; 0485105; 0485108; 0490552; 0506400; 0525641; 0531046; 0540231; 1528854; 1529838; 2 187 611; 53-108215; 53-137657; 57-39629; 58-107740; 58-161427; 58-161547; 60-24753; 61-70861; 62-133842; 62-502932; 63-28145; 63-180222; 63-180280; 63-253738; 64-5135; 64-68144; 64-74836; 2-94814; 2-141049; 2-154583; 2-166979; 2-195732; 2-218279; 2-260726; 2-278940; 3-13145; 3-48587; 3-69295; 04-196822; 4-322592; 5-75568; 5-167633; 5-218978; 7-79415; 7-99522; 2004-159207; 52118; 85/04541; 86-07223; 89/08366; 91/20137; 92/14343; 92/22162 |
| Other References: |
US. Office Action issued May 5, 2008 in U.S. Appl. Ser. No. 11,980,510. cited by other.
U.S. Office Action issued Jun. 24, 2008 in U.S. Appl. Ser. No. 11/905,978. cited by other.
Shinji Matsumoto et al., "200 Mb/s 16 QAM Digital Radio-Relay System Operating in 4 and 5 GHz Bands", Japan Telecommunications Review, Jan. 1982, vol. 24, No. 1, pp. 65-73. cited by other.
M. Pecot et al., "Compatible Coding of Television Images, Part 2. Compatible System", Signal Processing Image Communication, Oct. 2, 1990, No. 3, pp. 259-268. cited by other.
Mitsuaki Oshima, "Constellation-Code Division Multiplex for Digital HDTV", IEEE, 1992, pp. 1086-1092. cited by other.
Tricia Hill et al., "A Performance Study of NLA 64-State QAM", IEEE Transactions on Communications, vol. COM-31, Jun. 1983, No. 6, pp. 821-826. cited by other.
Hideki Ishio et al., "A Proposal of a Carrier Digital Transmission System Using Multi-Level APSK", pp. 1-20. cited by other.
Shanmugam, "Digital and Analog Communication Systems" 1979, p. 272. cited by other.
Khaled Fazel et al., Combined multilevel coding and multiresolution modulation, Feb. 8, 1993, pp. 1081-1085. cited by other.
P. Hoeher et al., Performance of an RCPC-Coded OFDM-based Digital Audio Broadcasting (DAB) System, IEEE Global Telecommunications Conference "Globecom '91", Dec. 2-5, 1991, vol. 1 of 3, pp. 2.1.1-2.1.7. cited by other.
K. M. Uz et al., Combined multiresolution source coding and modulation for digital broadcast of HDTV*, 1992, pp. 283-292. cited by other.
K. M. Uz et al., Multiresolution Source and Channel Coding for Digital Broadcast of HDTV, 1992, pp. 61-69. cited by other.
Nambi Seshadri et al.; Multi-Level Block Coded Modulations with Unequal Error Protection for the Rayleigh Fading Channel, vol. 4, No. 3, May-Jun. 1993, pp. 325-334. cited by other.
William F. Schreiber, Spread-Spectrum Television Broadcasting, SMPTE Journal, Aug. 1992, pp. 538-549. cited by other.
Martin Vetterli et al., Multiresolution Coding Techniques for Digital Television: A Review, Multidimensional Systems and Signal Processing, vol. 3, May 1992, pp. 161-187. cited by other.
Ezio Biglieri et al., Introduction to Trellia-Coded Modulation with Applications, Apr. 6, 1992, pp. 173-207. cited by other.
English Language Abstract of European Patent No. 93 30 7575. cited by other.
Kazuhiko Nitadori, Synthesis of Multichannel Orthogonal VSB Signals by Quadrature Method, 1976 International Conference on Communications, Jun. 14-16, 1976, vol. 1, pp. 3-25-3-29. cited by other.
Thomas M. Cover, Broadcast Channels, IEEE Transactions on Information Theory, Jan. 1972, pp. 2-14. cited by other.
"Optimum Weighted PCM for Speech Signals", Sundberg, IEEE Transactions on Communications, vol. COM-26, No. 6, Jun. 1978, pp. 872-881. cited by other.
Masafumi Saito et al., "Bit Error Rate Characteristics of OFDM in Multipath Environment", 1991. cited by other.
Ryutaro Ohmoto et al., ".pi./4-shift QPSK Subcarrier Transmission", 1991. cited by other.
Shigeki Moriyama et al., "Delay Propagation Characteristics at VHF and UHF bands in Urban Area", 1991 Spring National Convention Record, The Institute of Electronics, Information and Communication Engineers, Part 2, p. 406, Mar. 15, 1991. cited byother.
Yasuhiro Ito et al., "Adaptive Weignted Code Division Multiplexing (AW-CDM) Transmission System for Terrestrial Digital Television Broadcasting", ITE Technical Report vol. 17, No. 13, pp. 27-32, Feb. 25, 1993. cited by other.
J. A. C. Bingham, "Multicarrier Modulation for Data Transmission: An Idea Whose Time Has Come", IEEE Communications Magazine, vol. 28, May 1990, pp. 5-8 and 11-14. cited by examiner.
B. Hirosaki, "An Orthogonally Multiplexed QAM System Using the Discrete Fourier Transform", IEEE Transactions on Communications, vol. Com-29, No. 7, Jul. 1981, pp. 982-989. cited by examiner.
L. J. Cimini, Jr., "Analysis and Simulation of a Digital Mobile Channel Using Orthogonal Frequency Division Multiplexing", IEEE Transactions on Communications, vol. Com-33, No. 7, Jul. 1985, pp. 665-675 and Annex. cited by examiner. |
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| 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. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams 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. Furthermore, a communication system based on an OFDM system is utilized for data transmission of a plurality of subchannels, wherein the subchannels are differentiated by changing the length of a guard time slot or a carrier wave interval of a symbol transmission time slot, or changing the transmission electric power of the carrier. |
| Claim: |
What is claimed is:
.[.1. A signal transmission and reception apparatus for transmitting and receiving an n-level VSB signal, the apparatus comprising a transmitter and a receiver; saidtransmitter comprising: a compression means for compressing an input video signal to a digital video compression signal; an error correction encoding means for adding an error correction code to the digital video compression signal to produce an errorcorrection coded signal; a modulation means for modulating the error correction coded signal to an n-level VSB modulation signal, said modulation means comprising a means for allocating code points along a uniaxial modulation coordinate system, and afilter means having a plurality of coefficients which are a series of impulse responses defined by plotting timebase responses to the VSB modulation signal along the in-phase axis and its orthogonal axis for filtering a series of said code pointsallocated along the uniaxial modulation coordinate system; and a transmission means for transmitting the modulation signal, and said receiver comprising: a means for receiving a transmitted n-level VSB modulation signal; a demodulation means fordemodulating the received n-level VSB modulation signal into a digital reception signal; an error correction means for error correcting the digital reception signal to obtain an error-corrected digital signal; and an expanding means for expanding theerror-corrected digital signal to obtain a video output signal..].
.[.2. A transmission and reception apparatus according to claim 1, wherein the error correction means comprises a trellis decoder..].
.[.3. A transmission and reception apparatus according to claim 2, wherein the trellis decoder is associated with a plurality of memories which each holds a number of selectable correct codes..].
.[.4. A transmission and reception apparatus according to claim 1, wherein the digital reception signal is divided into a high priority signal and a low priority signal, and wherein said error correction means comprises a high code gain firsterror correction means and a low code gain second error correction means, said first error correction means correcting the high priority signal..].
.[.5. A transmission and reception apparatus according to claim 4, wherein the high priority signal carries the address data for all data..].
.[.6. A transmission and reception apparatus according to claim 4, wherein the first error correction means comprises a trellis decoder..].
.[.7. A signal transmission and reception apparatus according to claim 1, further comprising a band path filtering means for filtering the n-level VSB modulation signal before being transmitted..].
.[.8. A signal transmission and reception apparatus for transmitting an n-level VSB signal, comprising: a compression means for compressing an input video signal into a digital video compression signal; an error correction encoding means foradding an error correction code to the digital video compression signal to produce an error correction coded signal; a modulation means for modulating the error correction coded signal to an n-level VSB modulation signal, said modulation meanscomprising a means for allocating code points along a uniaxial modulation coordinate system, and a filter means having a plurality of coefficients which are a series of impulse responses defined by plotting timebase responses to the VSB modulation signalalong the in-phase axis and its orthogonal axis for filtering a series of said code points allocated along the uniaxial modulation coordinate system; and a transmission means for transmitting the modulation signal..].
.[.9. A signal transmission apparatus according to claim 8, further comprising a band path filtering means for filtering the n-level VSB modulation signal before being transmitted..].
.[.10. A signal receiving apparatus comprising: a tuner for receiving a transmission signal containing a digital modulation signal and an analog modulation signal and for selecting the digital modulation signal using a local oscillation signal; an interference detecting means for detecting interference caused by the analog modulation signal from the digital modulation signal selected by the tuner; a notch filter means responsive to the interference detected by the interference detecting meansfor removing a carrier of the analog modulation signal in a same frequency band as a frequency band of the digital modulation signal; an error ratio calculating means for calculating a bit error ratio of an output of the notch filter means; and anautomatic frequency correcting means for changing a frequency of the local oscillation signal of the tuner according to a level of the interference detected by the interference detecting means and the bit error ratio calculated by the error ratiocalculating means to compensate for a frequency offset of the carrier of the analog modulated signal..].
.[.11. A signal receiving apparatus according to claim 10, wherein the digital modulation signal is an n-level VSB modulation signal..].
.[.12. A signal receiving apparatus comprising: a tuner for receiving a transmission signal containing at least one of a VSB modulated signal and a QAM modulated signal and for selecting one of the VSB modulated signal and the QAM modulatedsignal to obtain a selected signal; an analog-to-digital converter for converting the selected signal into a series of digital codes; a transversal filter provided on an orthogonal axis for suppressing a transmission distortion of the series of digitalcodes with respect to both orthogonal axes to obtain a series of filtered digital codes allocated on the orthogonal axes; a carrier recovery means for phase-compensating a carrier of the filtered digital codes allocated on the orthogonal axis outputtedfrom the transversal filter; and a control means for producing a control signal to extract detected codes at equal time intervals from the VSB modulated signal; a clock reproducing means for phase synchronizing entire codes of the QAM modulated signalwhen the selected signal is the QAM modulated signal and for phase synchronizing codes of the VSB modulated signal intermittently at predetermined intervals when the selected signal is the VSB modulated signal; and a decoding means for decoding anoutput of the carrier recovery means..].
.Iadd.13. A signal transmission apparatus comprising: a modulator operable to modulate data for demodulation according to an m-level PSK and modulate a data stream according to an n-level PSK or an n-level QAM to produce modulated signals; anda transmitter operable to transmit the modulated signals, wherein said data for demodulation includes information representing the value of n..Iaddend.
.Iadd.14. A signal transmission apparatus according to claim 13, wherein m and n are integers, and m is equal to 2..Iaddend.
.Iadd.15. A signal receiving apparatus comprising: a receiver operable to receive an input signal to produce a received signal; and a demodulator operable to demodulate the received signal to produce data for demodulation and a data stream,wherein said input signal has information of the data for demodulation and the data stream, said data for demodulation is assigned to an m-level PSK, said data stream is assigned to an n-level PSK or an n-level QAM, said data for demodulation includesinformation representing the value of n, and said data stream is produced according to said information representing the value of n..Iaddend.
.Iadd.16. A signal receiving apparatus according to claim 15, wherein m and n are integers, and m is equal to 2..Iaddend.
.Iadd.17. A signal transmission system comprising a signal transmission apparatus and a signal receiving apparatus, said signal transmission apparatus comprising: a modulator operable to modulate data for demodulation according to an m-levelPSK and modulate a data stream according to an n-level PSK or an n-level QAM to produce modulated signals; and a transmitter operable to transmit the modulated signals, said signal receiving apparatus comprising: a receiver operable to receive atransmitted signal to produce a received signal, and a demodulator operable to demodulate the received signal to produce data for demodulation and a data stream, wherein said data for demodulation includes information representing the value of n, andsaid data stream is produced according to said information representing the value of n..Iaddend.
.Iadd.18. A signal transmission system according to claim 17, wherein m and n are integers, and m is equal to 2..Iaddend.
.Iadd.19. A signal transmission method comprising: modulating data for demodulation according to an m-level PSK and modulating a data stream according to an n-level PSK or an n-level QAM to produce modulated signals; and transmitting themodulated signals, wherein said data for demodulation includes information representing the value of n..Iaddend.
.Iadd.20. A signal transmission method according to claim 19, wherein m and n are integers, and m is equal to 2..Iaddend.
.Iadd.21. A signal receiving method comprising: receiving an input signal to produce a received signal; and demodulating the received signal to produce data for demodulation and a data stream, wherein said input signal has information of thedata for demodulation and the data stream, said data for demodulation is assigned to an m-level PSK, said data stream is assigned to an n-level PSK or an n-level QAM, said data for demodulation includes information representing the value of n, and saiddata stream is produced according to said information representing the value of n..Iaddend.
.Iadd.22. A signal receiving method according to claim 21, wherein m and n are integers, and m is equal to 2..Iaddend.
.Iadd.23. A signal transmission method comprising a signal transmission method and a signal receiving method, said signal transmission method comprising: modulating data for demodulation according to an m-level PSK and modulating a data streamaccording to an n-level PSK or an n-level QAM to produce modulated signals; and transmitting the modulated signals, said signal receiving method comprising: receiving a transmitted signal to produce a received signal, and demodulating the receivedsignal to produce data for demodulation and a data stream, wherein said data for demodulation includes information representing the value of n, and said data stream is produced according to said information representing the value of n..Iaddend.
.Iadd.24. A signal transmission method according to claim 23, wherein m and n are integers, and m is equal to 2..Iaddend. |
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