Communication system

• US 8,160,173 B2
• Filed: 04/29/2009
• Issued: 04/17/2012
• Est. Priority Date: 03/26/1992
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Oshima, Mitsuaki
• Primary Examiner(s): Kim, Kevin
• Application Number:
  US12/432,287
• Publication Number:
  US 20090274240A1
• Time in Patent Office: 1,084 Days
• Field of Search: 375/270, 375/277
• US Class Current: 375/270
• 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 1/0041 Arrangements at the transmitter end
• 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 1/006 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 2027/0036 using a recovered symbol clock
• CPC Class Codes: H04L 2027/0053 Closed loops
• CPC Class Codes: H04L 2027/0067 Phase error detectors
• 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 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
• CPC Class Codes: H04L 27/3488 Multiresolution systems
• CPC Class Codes: H04L 27/36 : Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/38 : Demodulator circuits; Receiver circuits
• 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 19/36 : Scalability techniques involving formatting the layers as a function of picture distortion after decoding, e.g. signal-to-noise [SNR] scalability
• 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 21/4621 : Controlling the complexity of the content stream or additional data, e.g. lowering the resolution or bit-rate of the video stream for a mobile client with a small screen arrangements for using the results of monitoring on user's side in broadcast systems H04H60/65; flow control in packet networks H04L47/10
• CPC Class Codes: H04N 21/64792 : Controlling the complexity of the content stream, e.g. by dropping packets intermediate media network packet handling H04L65/765; proxy provisioning conversion or adaptation for reducing the amount or size of exchanged application data H04L67/5651; negotiation of resources in wireless networks H04W28/16
• 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. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. 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.

Claims

1. A signal transmission apparatus comprising:

a modulator operable to modulate a first data stream according to an m-level VSB to produce a modulated signal of a first layer, and modulate a second data stream according to an n-level VSB to produce a modulated signal of a second layer;

wherein an amplitude of m-level VSB modulation scheme is different from an amplitude of n-level VSB modulation scheme; and

a transmitter transmit the modulated signal of the first layer and the modulated signal of the second layer;

wherein the electric power of the modulated signal of the first layer is different from the electric power of the modulated signal of the second layer.

2. A signal receiving apparatus comprising:

a receiver operable to receive a modulated signal of a first layer and a modulated signal of a second layer; and

wherein the modulated signal of the first layer has information of a first data stream and the modulated signal of the second layer has information of a second data stream, the modulated signal of the first layer is modulated according to an m-level VSB and the modulated signal of the second layer is modulated according to an n-level VSB,

and wherein an amplitude of m-level VSB modulation scheme is different from an amplitude of n-level VSB modulation scheme;

a demodulator operable to demodulate the modulated signal of the first layer according to m-level VSB to produce the first data stream, and demodulate the modulated signal of the second layer according to n-level VSB to produce the data stream;

wherein the electric power of the modulated signal of the first layer is different from the electric power of the modulated signal of the second layer.

3. A signal transmission method comprising:

modulating a first data stream according to an m-level VSB to produce a modulated signal of a first layer, and modulating a second data stream according to an n-level VSB to produce a modulated signal of a second layer;

wherein an amplitude of m-level VSB modulation scheme is different from an amplitude of n-level VSB modulation scheme; and

transmitting the modulated signal of the first layer and the modulated signal of the second layer;

wherein the electric power of the modulated signal of the first layer is different from the electric power of the modulated signal of the second layer.

4. A signal receiving method comprising:

receiving a modulated signal of a first layer and a modulated signal of a second layer; and

wherein the modulated signal of the first layer has information of a first data stream and the modulated signal of the second layer has information of a second data stream, the modulated signal of the first layer is modulated according to an m-level VSB and the modulated signal of the second layer is modulated according to an n-level VSB,

and wherein an amplitude of m-level VSB modulation scheme is different from an amplitude of n-level VSB modulation scheme;

demodulating the modulated signal of the first layer according to m-level VSB to produce the first data stream, and demodulating the modulated signal of the second layer according to n-level VSB to produce the data stream;

wherein the electric power of the modulated signal of the first layer is different from the electric power of the modulated signal of the second layer.

5. A signal transmission apparatus comprising:

a modulator operable to modulate a first data stream according to an m-level PSK or an m-level QAM to produce a modulated signal of a first layer, and modulate a second data stream according to an n-level PSK or an n-level QAM to produce a modulated signal of a second layer;

wherein an amplitude of m-level PSK modulation scheme or m-level QAM modulation scheme is different from an amplitude of n-level PSK modulation scheme or m-level QAM modulation scheme; and

a transmitter transmit the modulated signal of the first layer and the modulated signal of the second layer;

wherein the electric power of the modulated signal of the first layer is different from the electric power of the modulated signal of the second layer.

6. A signal receiving apparatus comprising:

a receiver operable to receive a modulated signal of a first layer and a modulated signal of a second layer; and

wherein the modulated signal of the first layer has information of a first data stream and the modulated signal of the second layer has information of a second data stream, the modulated signal of the first layer is modulated according to an m-level PSK or an m-level QAM and the modulated signal of the second layer is modulated according to an n-level PSK or an n-level QAM,

and wherein an amplitude of m-level PSK modulation scheme or m-level QAM modulation schemes is different from an amplitude of n-level PSK modulation scheme or n-level QAM modulation scheme;

a demodulator operable to demodulate the modulated signal of the first layer according to m-level PSK or m-level QAM to produce the first data stream, and demodulate the modulated signal of the second layer according to n-level PSK or n-level QAM to produce the data stream;

wherein the electric power of the modulated signal of the first layer is different from the electric power of the modulated signal of the second layer.

7. A signal transmission method comprising:

modulating a first data stream according to an m-level PSK or an m-level QAM to produce a modulated signal of a first layer, and modulating a second data stream according to an n-level PSK or an n-level QAM to produce a modulated signal of a second layer;

wherein an amplitude of m-level PSK modulation scheme or m-level QAM modulation scheme is different from an amplitude of n-level PSK modulation scheme or n-level QAM modulation scheme; and

transmitting the modulated signal of the first layer and the modulated signal of the second layer;

wherein the electric power of the modulated signal of the first layer is different from the electric power of the modulated signal of the second layer.

8. A signal receiving method comprising:

receiving a modulated signal of a first layer and a modulated signal of a second layer; and

wherein the modulated signal of the first layer has information of a first data stream and the modulated signal of the second layer has information of a second data stream, the modulated signal of the first layer is modulated according to an m-level PSK or an m-level QAM and the modulated signal of the second layer is modulated according to an n-level PSK or an n-level QAM,

and wherein an amplitude of m-level PSK modulation scheme or m-level PSK modulation scheme is different from an amplitude of n-level PSK modulation scheme or n-level QAM modulation scheme;

demodulating the modulated signal of the first layer according to m-level PSK or m-level QAM to produce the first data stream, and demodulating the modulated signal of the second layer according to n-level PSK or n-level QAM to produce the data stream;

wherein the electric power of the modulated signal of the first layer is different from the electric power of the modulated signal of the second layer.