JPH04150524A - Pcm music broadcasting terminal equipment - Google Patents

Abstract

PURPOSE:To obtain the program of PCM music broadcasting by a CATV system provided with a satellite broadcasting receiver through a simple device by providing a tuner part, a modulating part, and a frequency converting part. CONSTITUTION:The PCM-modulated and four-phase DPSK-modulated signal of music broadcasting is inputted to an input terminal 101 from the transmission line of the CATV system. The signal inputted to the input terminal 101 is channel-selected by the tuner part 102, and is converted into definite frequency, and is FM-modulated by the modulating part 103. This FM-modulation of the PCM-modulated and four-phase DPSK-modulated signal is executed under the same condition that the sound signal of satellite broadcasting was FM- modulated. The FM-modulated signal is converted into the frequency of a free channel of the satellite broadcasting by the frequency converting part 104, and is outputted from an output terminal 107. Then, by demodulating it by the satellite broadcasting receiver. the program of the PCM music broadcasting of the CATV system can be obtained through the simple device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a CATV (Cable Television System) subscriber terminal device, and more particularly to a PCM music broadcasting terminal device.

[Conventional technology]

A conventional PCM music broadcasting terminal device will be explained with reference to the drawings.

FIG. 3 is a block diagram of a conventional PCM music broadcasting terminal device. A signal of a music broadcast program of a CATV system from an input terminal 301 is input to a tuner section 302 . The tuner section 302 tunes the aforementioned signal that is PCM modulated and 4-phase DPSK (differential phase shift keying) modulated and is transmitted in the CATV transmission band, and -
As an example, the frequency is converted to 5.73MHz. The frequency-converted signal is converted into PCM by the 4-phase DPSK demodulator 303.
After being converted into a signal, it is converted back into an audio signal by a PCM demodulator 304 and output from an output terminal 307. Here, 305 is an operation key for controlling the CPU 1306 which controls the tuning of the tuner section 302.

[Problem to be solved by the invention]

The above-mentioned conventional PCM music broadcasting terminal device uses 4-phase DPSK and PCM signals in order to receive PCM music broadcasting in which the signal is PCM modulated and 4-phase DPSK modulated and transmitted with the same specifications as satellite broadcasting. each demodulator. There is a problem in that CATV subscribers who have satellite broadcast receivers have this part redundantly.

[Means to solve the problem]

The PCM music broadcasting terminal device of the present invention is a PCM music broadcasting terminal device that receives a PCM modulated and 4-phase DPSK modulated signal in the same format as a satellite broadcasting audio signal through a transmission path of a CATV system, and selects a channel for the signal. a tuner section that converts the frequency to a constant frequency; a modulation section that further FM-modulates the signal output from the tuner section so as to have the same conditions as the received audio signal of the satellite broadcast; It has a frequency conversion unit that converts the frequency to an available satellite broadcasting channel.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a PCM music broadcasting terminal according to the present invention. From the transmission line of the CATV system, PCM
A music broadcast signal subjected to modulation and four-phase DPSK modulation is input to the input terminal 101.

This signal is modulated in the same format as satellite broadcasting, except that it is not further FM modulated (frequency modulated). The signal input to the input terminal 101 is tuned by the tuner section 102 and tuned to a fixed frequency 4, for example, 5.73.
It is converted to a frequency of MHz. To select a station, use operation key 106
This is performed by the CPU 105 controlling the tuner section 102 by the operation. The selected signal output from tuner section 102 is subjected to FM modulation at modulation section 103 .

FM of this PCM modulated and 4-phase DPSK modulated signal
Modulation is performed under the same conditions as when satellite broadcast audio signals are FM modulated. The FM modulated signal is sent to the frequency converter 10.
4, the signal is converted to the frequency of an available satellite broadcasting channel (for example, the first channel of satellite broadcasting, frequency 11.72748 GHz), and is output from the output terminal 107.

FIG. 2 is an example of the use of the embodiment of FIG.

A CATV music broadcast signal inputted from the input terminal 202 is converted by the music broadcast terminal device 203 according to the embodiment into the frequency of an empty satellite broadcast channel (for example, the first channel) and output. This signal is mixed with the satellite broadcast reception signal from input terminal 201 by mixer 204 and input to satellite broadcast receiver 205 .

In the satellite broadcasting receiver 205, the FM demodulator and the 4-phase D
It has a PSK demodulation section and a PCM demodulation section, and when the first channel is selected, it is possible to listen to the PCM music broadcast of the CATV system, and it is also possible to select the normal satellite broadcast. Note that a speaker 207 is connected to the satellite broadcast receiver 205 via an audio amplifier 20B.
Music broadcasts can be listened to, and a television (TV) 208 can be connected so that television can be viewed.

〔Effect of the invention〕

As described above, the PCM music broadcast terminal device of the present invention modulates the music broadcast signal transmitted from the CATV system into a signal having the same conditions as the satellite broadcast audio signal. Then, by converting the frequency to an available satellite broadcasting channel and demodulating it with a satellite broadcasting receiver,
This has the advantage of being able to provide PCM music broadcast programs for CATV systems with a simple device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a diagram showing an example of its use, and FIG. 3 is a block diagram of a conventional example. 101.201,202,301...input terminal, 10
2.302...Tuner section, 103...Modulation section, 1
04...Frequency conversion unit, 105.305...CPU
110B, 306... operation unit, 107, 207°30
7... Output terminal, 203... PCM music broadcast terminal device, 204... Mixer, 205... Satellite broadcast receiver, 206... Audio amplifier, 207... Speaker, 2
08...Television (TV), 303...4 phase DPSK
Demodulation section, 304... PCM demodulation section.

Claims (1)

[Claims] 1. In a PCM music broadcasting terminal device that receives PCM-modulated and 4-phase DPSK-modulated signals in the same format as satellite broadcasting audio signals through a transmission line of a CATV system, the signals are tuned and fixed. and a tuner section that converts the frequency into an FM frequency.
A PCM music broadcasting terminal device comprising: a modulation section that performs modulation; and a frequency conversion section that converts the frequency of the FM-modulated signal to the vacant channel of the satellite broadcasting. 2. A satellite broadcasting receiver characterized in that the output signal of the PCM music broadcasting terminal device according to claim 1 is included as a reception input signal.