JPS5824997B2 - Multi-frequency signal reception method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-frequency signal reception method, and in particular to a method for converting an input signal, which is a signal used for audio frequency dial signals, etc., consisting of a plurality of different frequencies into a DC output signal, and converting the input signal to a DC output signal. The present invention relates to a signal receiving method for applying a signal to corresponding points among a plurality of output points according to the frequency of the input signal.

Conventionally, a configuration as shown in FIG. 1 has been used as this type of multi-frequency signal receiver.

That is, when a plurality of mixed signal waves of different frequencies arrive at the input terminal IN, the mixed signal waves are first transferred to a common band P.
It passes through the wave device MBF.

This common band r wave filter MBF is for separating the selected signal group from the signal outside the frequency band which is mixed into the input terminal IN in a pre-required frequency band.

The output of this mud wave device MBF is branched and given to a plurality of separation circuits CHBPF provided for each frequency.

Each separation circuit CHBPF is constituted by a band P-wave device having its own pass frequency band, and extracts a wave of a selected frequency from a frequency group of an input signal and outputs only its component.

The output of each separation circuit CHBPF is connected to the input of a discrimination circuit DBT provided corresponding to each frequency, and is compared with a threshold value, and the result is converted into a binary pulse signal and output to Xo to Xn, respectively. be done.

In the conventional multi-frequency signal receiver having such a configuration, the separation circuit CHBPF requires a band P-wave device each having the same number of unique pass frequency bands as the number of input signal frequencies.

The design of these band offshore wave devices is complicated because it requires the design of many types of P-wave devices, and it is also difficult to manufacture many types of P-wave devices.

The present invention improves on this, and aims to provide a multi-frequency signal receiving system configured by one type of Oki waver circuit.

The present invention includes a first switch connected to an input terminal, a p-wave switch whose input is connected to the first switch, and a plurality of second switches connected to the output of the oki wave switch. , a separation circuit whose input is connected to this second switch, and a discrimination circuit connected to this separation circuit, and a single sideband wave whose carrier frequency is the frequency at which the first switch is opened/closed is transmitted as described above. It is characterized in that it is configured to extract the frequency using a p-wave detector and open and close a plurality of second switches at the frequency to be detected.

Next, the present invention will be described in more detail with reference to the drawings.

FIG. 2 is a circuit configuration diagram showing an embodiment of the present invention.

A first switch S1 is connected to the input terminal IN, and its output is connected to a second switch 52j (j=0''n) provided for each frequency band via a common P-wave device CF. has been done.

The output of each switch S2J is connected to a separation circuit CH composed of band p-wave devices each having the same type of passing frequency band.
It is connected to a BPF, and its output is connected to the input of a discrimination circuit DET provided corresponding to each frequency band.

The operation of the device configured in this way will be explained.

The operation is based on the input signal frequency that reaches the input terminal IN.
(t=o to n), and the carrier frequency f is applied to the switching signal supplied to the switch S1 from the terminal C1.

Assume that a pulse signal of □ is given.

The output of switch S1 has both side band waves. fSi + fC mouth 1fSi - fC, 1 and a carrier wave f.

Both-side band waves due to odd-numbered harmonics of 1 are output.

The pass band of this output is limited by the common wave transducer CF connected to the next stage, and only single sideband waves lfc and -fsi I are extracted as the output.

The output of this common wave transducer CF is the carrier wave frequency f supplied from each terminal C7 in the switch S2j.

2. It is opened and closed by the gate pulse signal, and its output is l fcl~fSi -fC2j 1 fclf5i + f(4j and the carrier wave f.

Both side band waves due to odd-numbered harmonics of 2j are generated.

As this carrier frequency fo2j, f8. By choosing , the sideband waves of the fundamental wave become l fcz fsi fsi 1 fC1-fSi+fSJ.

The modulation frequency f of the first switch S8 as each separation circuit CHBPF.

By using a bandpass transducer whose passband is 1, the frequency fc1 is outputted to the output of the separation circuit CHBPF of the channel i=J, and the frequency fc1 is outputted to the output of the separation circuit CHBPF of the channel i\j. Only the leaked portion of fclfsi +fsj is output.

The leakage component is maximum when i=j±1, that is, when the wave is in an adjacent band, but these can be discriminated by appropriately configuring the characteristics of the separation circuit CHBPF.

Further, it is clear that the harmonic double sideband waves are removed by the separation circuit CHBPF.

The operation of the discriminator circuit DET connected at the subsequent stage is the same as that of the conventional example shown in FIG.

As can be understood from such an operation, the separation circuit CHBPF placed corresponding to the input signal frequency may have the same characteristics for all channels.

Further, since the control signal supplied to the second switch S2j is equal to the frequency of each multifrequency signal, it can be obtained more easily than the transmitting device normally paired with the receiving device.

In addition to the common filter CF described in the above example, any type of filter may be used as long as it is a source filter that converts both sideband waves into a single sideband wave.

For example, in the above example, a low-pass type is used instead of a high-pass type for the common P-wave device CF, and f8i ten f.

The present invention can be similarly implemented by extracting a single sideband wave of .

As explained above, according to the present invention, it is possible to share the separation circuit using one type of source circuit, which is convenient for mass production and particularly effective for economical industrialization.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a conventional device. FIG. 2 is a circuit diagram of a device according to an embodiment of the present invention.

Claims (1)

[Claims] 1 A first switch S1 connected to an input terminal, a mud wave device CF whose input is connected to this first switch, and a plurality of second switches connected to the output of this P wave device S2j and a separation circuit CHBPF whose input is connected to this second switch
and a discriminator circuit DET connected to the output of this separation circuit, and a single sideband device CF whose carrier frequency is the frequency at which the first switch is opened/closed, extracts the signal from the plurality of second switches S. , j are configured to open and close at frequencies to be detected.