Unlock instant, AI-driven research and patent intelligence for your innovation.

Communication system

a communication system and communication technology, applied in the field of communication systems, can solve the problems of inability to go further, inability to corresponding ntsc channels to be available, and inability to reach further, so as to achieve the effect of increasing the service area and reducing the signal attenuating area

Inactive Publication Date: 2008-03-25
PANASONIC CORP
View PDF157 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

"The present invention provides a communication system that can be used for both NTSC and HDTV broadcast services using satellite. The system uses a modified QAM signal with signal points that are assigned to different data streams, allowing for compatibility with different receivers. The system also includes a demodulator circuit that can handle large amounts of data and can be used for multi-level signal transmission. The system ensures compatibility with existing NTSC TV signals and allows for future extension. The use of a small-sized antenna for HDTV signals can be extended to larger areas, while a large-sized antenna can be used for both NTSC and HDTV signals. The system also allows for the simultaneous broadcast of NTSC and HDTV signals using a single satellite."

Problems solved by technology

However, the TV broadcast service is a public business and cannot go further without considering the interests and benefits of viewers.
This causes the corresponding NTSC channels to be unavailable during the transmission of the HDTV signal.
In any analogue TV broadcast service, there are developed a lot of signal attenuating or shadow regions within its service area due to structural obstacles, geographical inconveniences, or signal interference from a neighbor station.
When the TV signal is an analogue fromform, it can be intercepted more or less at such signal attenuating regions although its reproduced picture is low in quality.
This disadvantage is critically hostile to the development of any digital TV system.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Communication system
  • Communication system
  • Communication system

Examples

Experimental program
Comparison scheme
Effect test

embodiment 1

[0227]One embodiment of the present invention will be described referring to the relevant drawings.

[0228]In the preferred embodiment of the invention both the transmission apparatus, which comprises a transmitter for transmitting a digital HDTV signal or other digital signal and a receiver for receiving the transmitted signal, and the recording and reproducing apparatus, which records the digital HDTV signal or other digital signal on a magnetic tape or other recording medium and reproduces the recorded signal from said medium, are described.

[0229]It should be noted, however, that the configuration, operation, and principle of the digital modulator and demodulator, error correction encoder and decoder, and the encoder and decoder for image coding the HDTV signal are common to the transmission apparatus and the recording and reproducing apparatus, and apply essentially the same technologies. Therefore, to more concisely describe each embodiment, the block diagrams for either the tran...

embodiment 2

[0335]A second embodiment of the present invention is featured in which the physical multi-level arrangement of the first embodiment is divided into small levels through e.g. discrimination in error correction capability, thus forming a logic multi-level construction. In the first embodiment, each multi-level channel has different levels in the electricalelectric signal amplitude or physical demodulating capability. The second embodiment offers different levels in the logic reproduction capability such as error correction. For example, the data D1 in a multi-level channel is divided into two, D1-1 and D1-2, components and D1-1 is more increased in the error correction capability than D1-2 for discrimination. Accordingly, as the error detection and correction capability is different between D1-1 and D1-2 at demodulation, D1-1 can successfully be reproduced within a given error rate when the C / N level of an original transmitting signal is as low as disenabling the reproduction of D1-2...

embodiment 3

[0358]A third embodiment of the present invention will be described referring to the relevant drawings.

[0359]FIG. 29 is a schematic total view illustrating the third embodiment in the form of a digital TV broadcasting system. An input video signal 402 of super high resolution TV image is fed to an input unit 403 of a first video encoder 401. Then, the signal is divided by a divider circuit 404 into three, first, second, and third, data streams which are transmitted to a compressing circuit 405 for data compression before being further delivered.

[0360]Equally, other three input video signals 406, 407, and 408 are fed to a second 409, a third 410, and a fourth video encoder 411 respectively which all are arranged identical in construction to the first video encoder 401 for data compression.

[0361]The four first data streams from their respective encoders 401, 409, 410, and 411 are transferred to a first multiplexer 413 of a multiplexer 412 where they are time multiplexed by a TDM proce...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation-in-part of application Ser. No. 07 / 857,627, filed Mar. 25, 1992, pending.This is a reissue application of U.S. Pat. No. 5,600,672, issued Feb. 4, 1997, and a divisional application of reissue application No. 09 / 244,037, filed Feb. 4, 1999, which is also a reissue application of U.S. Pat. No. 5,600,672, issued Feb. 4, 1997 which is a Continuation-In-Part of application Ser. No. 07 / 857,627, filed Mar. 25, 1992 now abandoned. Further reissue divisional applications have been filed, all of which are reissues of Pat. No. 5,600,672. These further applications are: 09 / 677,421, filed Oct. 5, 2000; 09 / 678,014, filed Oct. 5, 2000; 09 / 677,420, filed Oct. 5, 2000; 09 / 680,177, filed Oct. 5, 2000; 09 / 680,176, filed Oct. 5, 2000; 09 / 686,467, filed Oct. 12, 2000; 09 / 686,463, filed Oct. 12, 2000; 09 / 686,466, filed Oct. 12, 2000; 09 / 688,028, filed Oct. 12, 2000; 09 / 686,464, filed Oct. 12, 2000; 09 / 686,465, filed Oct. 12, ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(United States)
IPC IPC(8): H04L5/16H04B1/38
CPCH04L27/36H04L27/38H04L27/34H04L27/16H04L27/0014H04L2027/0016H04L2027/0026H04L2027/0069H04L27/0008H04L27/066H04L1/0042H04L1/0047H04L1/006H04L2001/0093H04N21/2383H04N21/4425H04N21/4382H04L27/3405
Inventor OSHIMA, MITSUAKISAKASHITA, SEIJI
Owner PANASONIC CORP