Digital broadcasting receiver

Details Digital broadcasting receiver Digital broadcasting receiver

1998-12-22

2002-08-06

Pham, Chi (Department: 2631)

Pulse or digital communications

Receivers

Particular pulse demodulator or detector

C709S241000, C455S186100, C375S349000

Reexamination Certificate

active

06430236

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a digital broadcasting receiver capable of receiving signals of not less than two types of digital broadcasting among digital satellite broadcasting, digital ground wave broadcasting and digital CATV broadcasting.
2. Description of the Related Art
As shown in
FIG. 2
, a conventional digital broadcasting receiver includes: a tuner
100
for converting a digital satellite broadcasting signal into an intermediate-frequency signal; a tuner
110
for converting a digital ground wave broadcasting signal into an intermediate-frequency signal; a tuner
120
for converting a digital CATV broadcasting signal into an intermediate-frequency signal; A/D converters
200
,
200
,
200
for digitizing the intermediate-frequency signals respectively sent from the tuners
100
,
110
,
120
; a satellite broadcasting demodulating section
350
for demodulating a digital signal sent from the first A/D converter
200
; a ground wave broadcasting demodulating section
360
for demodulating a digital signal sent from the second A/D converter
200
; a CATV broadcasting demodulating section
370
for demodulating a digital signal sent from the third A/D converter
200
; a changeover switch
450
for selecting one of the signals sent from the satellite broadcasting demodulating section
350
, the ground wave broadcasting demodulating section
360
and the CATV broadcasting demodulating section
370
; a transport
500
for separating and dividing the signal selected by the changeover switch
450
; a decoder
600
for decoding the signal sent from the transport
500
; and a CRT
700
for displaying an image of the signal sent from the decoder
600
.
The conventional digital broadcasting receiver
5
further includes: a control section
810
for controlling the tuners
100
,
110
,
120
, the changeover switch
450
and the transport
500
; a key input section
860
which is one of the setting input sections of the control section
810
; and a remote control receiving section
850
for receiving the signals sent from a remote control transmitting unit
900
which is the other setting input section and which is provided separately from the digital broadcasting receiver
5
.
For example, as disclosed in Japanese Patent Unexamined Publication No. Hei. 6-54011, a QPSK demodulating circuit of the satellite broadcasting demodulating section
350
, by which a pure demodulating function can be exhibited, includes: five multipliers; three filters; a 90° phase shifter; a voltage-controlled oscillator; a clock regenerating circuit; two waveform shaper; and a subtracter, wherein all of them can be realized as digital circuits.
Of course, an error corrector, which is the residual function of the satellite broadcasting demodulating section
350
, can be also realized as a digital circuit.
On the other hand, although not described in the above publication, the ground wave broadcasting demodulating section
360
is composed of an 8-value VSB demodulator or an OFDM demodulator and an error corrector, wherein all of them can be realized as digital circuits. The CATV broadcasting demodulating section
370
is composed of a 16-value VSB demodulator or a 256-value QAM demodulator and an error corrector, wherein all of them can be realized as digital circuits.
In the above publication, attention is paid to a portion of hardware which is common between the QPSK demodulating circuit and the MSK demodulating circuit, and a method of reducing hardware is disclosed as an invention.
However, in the conventional digital broadcasting receiver
5
composed in the manner described above, the satellite broadcasting demodulating section
350
, the ground wave broadcasting demodulating section
360
and the CATV broadcasting demodulating section
370
are required respectively for receiving digital satellite broadcasting, ground wave broadcasting and CATV broadcasting. Therefore, the number of necessary parts is necessarily increased and the manufacturing cost is raised.
When the method described in the above publication is adopted to reduce hardware, it is possible to decrease the number of necessary parts and reduce the manufacturing cost, however, the decrease of the number of necessary parts is limited because attention is paid only to hardware.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a digital broadcasting receiver, the number of necessary parts of which is decreased so that the manufacturing cost can be reduced.
In order to achieve the above object, the present invention provides a digital broadcasting receiver capable of receiving a plurality of types of digital broadcasting, comprising: a software utilizing demodulating section for demodulating a digitized intermediate-frequency signal; a memory for storing software to be used in the software utilizing demodulating section so that each digital broadcasting capable of being received is demodulated; and a control section for giving a command by which the software to demodulate each digital broadcasting is selectively taken from the memory into a memory which is built in the software utilizing demodulating section according to a setting made by a setting input section.


REFERENCES:
patent: 6072994 (2000-06-01), Phillips et al.
patent: 6115434 (2000-09-01), Mizobata et al.
patent: 6151354 (2000-11-01), Abbey
patent: 6167099 (2000-12-01), Rader et al.
patent: 6181734 (2001-01-01), Palermo
patent: 6-54011 (1994-02-01), None

Affiliated with

Also associated with

Rating

Digital broadcasting receiver does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Digital broadcasting receiver, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Digital broadcasting receiver will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2923013