KR19980063157A - Al2 Signal Detection Device Using Down Sampling Technique - Google Patents

Abstract

The technical field to which the invention described in the claims belongs.

A device for detecting an R2 signal.

I. The technical problem that the invention is trying to solve

An apparatus for detecting an R2 signal using a down sampling technique is provided.

All. Summary of Solution of the Invention

An apparatus for detecting an R2 signal using a down sampling technique, comprising: an A / D converter for inputting the R2 signal, sampling at 8 KHz, converting the linear data into a linear data, and outputting the linear data; The low pass filter outputs the frequency above 1.2KHz or more in the case of the backword, and the decimator resamples and outputs the signal to 4KHz when the signal is inputted from the low pass filter. 6 band pass filters for passing only a frequency corresponding to each frequency band and measuring a power of the passed frequency and outputting a power measurement signal, and receiving the power measurement signal from the six band pass filters. It is characterized by consisting of decision logic to receive and output the digit information.

la. Important uses of the invention

Used to detect R2 signals.

Description

Alto signal detection device using down sampling technique.

The present invention relates to an apparatus for detecting an Alto (hereinafter referred to as R2) signal, and more particularly, to an apparatus for detecting an R2 signal using a down sampling technique.

The R2 signal is mainly used for address signaling during the exchange period. The R2 code used for the R2 signal was standardized for European signaling in 1968, and six frequencies are used in the forward and the backward, respectively.

The R2 signal signals 15 pieces of digit information by using two combinations of six frequencies in each direction. Table 1 below shows the frequency configuration of the R2 signal.

signal Frequency (Hz) Forward 1380 1500 1620 1740 1860 1980 Backward 1140 1020 900 780 660 540 One * * 2 * * 3 * * 4 * * 5 * * 6 * * 7 * * 8 * * 9 * * 10 * * 11 * 12 * * 13 * * 14 * * 15 * *

In addition, the R2 signal configured as shown in Table 1 is signaled using a Fully Compelled method. In the pulley compand method, the backword signal is started after the minimum recognition time required to recognize the input signal when the forward signal is received. Each function of the R2 code and the R2 signaling shown in Table 1 are well known in the art, and thus detailed descriptions thereof will be omitted.

The conventional R2 signaling has been detected as follows.

First, when an R2 signal is input as a Pulse Cord Modulation (PCM) signal through a telephone line connected to an exchange, an analog / digital converter is called A / D. It is sampled at 8KHz, converted into linear data, and output to a low pass filter (hereinafter referred to as LPF). In the case of forward signaling, the LPF filters six or more frequency signals and outputs six band pass filters (hereinafter referred to as BPFs). In the case of backword signaling, the LPF filters six or more frequency signals of 1.2 KHz and outputs six band pass filters (hereinafter referred to as BPFs). Then, the BPF inputs the filtered signal and passes a frequency corresponding to each of a predetermined set band, and measures the power of the passed signal and outputs a power measurement signal to decision logic. The decision logic receives the power measurement signals inputted from the six BPFs, and finds the corresponding digit information through two frequency signals corresponding to the corresponding reference power.

As described above, the detection of the conventional R2 signal has a disadvantage in that the number of channels that can be processed by one unit signal processing increases because more data to be processed by processing the signal by sampling at 8KHz. This also required more signal processors to increase the price of the overall system.

Accordingly, an object of the present invention is to provide an R2 signal detection apparatus that increases processing capacity by greatly reducing data to be processed using a down sampling technique.

1 is a block diagram of an apparatus for detecting a forward alto signal using a down sampling technique according to an exemplary embodiment of the present invention.

2 is a block diagram of an apparatus for detecting a backward alto signal using a down sampling technique according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals have the same reference numerals as much as possible even if displayed on different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

As shown in Table 1, since the frequencies constituting the R2 signal do not exceed 2 KHz, the present invention applies a down-sampling technique that lowers the sampling frequency (hereinafter referred to as Fs) to a range where the signal is not damaged.

1 is a block diagram of an apparatus for detecting a forward R2 signal using a down sampling scheme according to an exemplary embodiment of the present invention.

First, when the R2 signal is input through a telephone line connected to the switch as a PCM signal, the A / D converter 100 samples the R2 signal at 8KHz, converts the linear signal into linear data, and outputs the LPF 200. Then, the LPF 200 outputs the filtered signal to the decimator 300 by filtering the frequency signal of 2KHz or more. Then, the decimator 300 samples the filtered signal again at 4KHz and outputs a sampled signal with a high pass filter (hereinafter referred to as 400 HPF). The HPF 400 then outputs the filtered signals to six BPFs 500-550 by filtering frequencies below 1.2 KHz when the sampled signals are input to obtain better signals. As can be seen from Table 1, the frequencies constituting the forward R2 signal are all 1.2 KHz or more. Then, the six BPFs 500-550 input the filtered signals to pass frequencies corresponding to their respective set bands, and measure the power of the passed signals to transmit power measurement signals to the decision logic 600. Output Then, the decision logic 600 receives the power measurement signals input from the six BPFs and finds the corresponding digit information through two frequency signals corresponding to the double reference power. The decision logic 600 may use a conventional decision logic as it is.

2 is a block diagram of an apparatus for detecting a backward word R2 signal using a down sampling technique according to an exemplary embodiment of the present invention.

First, when the R2 signal is input through a telephone line connected to the switch as a PCM signal, the A / D converter 100 samples the R2 signal at 8KHz, converts the linear signal into linear data, and outputs the LPF 200. Then, the LPF 200 outputs the filtered signal to the decimator 300 by filtering the frequency signal of 1.2KHz or more. Then, the decimator 300 samples the filtered signal again at 4KHz and outputs the filtered signals to six BPFs 500-550. Then, the six BPFs 500-550 input the filtered signals to pass frequencies corresponding to their respective set bands, and measure the power of the passed signals to transmit power measurement signals to the decision logic 600. Output Then, the decision logic 600 receives the power measurement signals inputted from the six BPFs 500-550F and finds the corresponding digit information through two frequency signals corresponding to the dual reference power. The decision logic 600 may use a conventional decision logic as it is.

As described above, the present invention can increase the processing capacity by greatly reducing the amount of data to be processed by using the downsampling technique, and thus can process more channels in one unit signal processor.

Claims (2)

An apparatus for detecting an alto signal using a down sampling technique connected to a telephone line connected to a counterpart exchange, An analog-to-digital converter for sampling the 8-kHz signal and converting it to linear data when the alto signal is input from the telephone line; A low pass filter connected to the analog / digital converter and filtering and outputting frequencies of 2 kilohertz or more in the case of a forward when the linear data is input, and outputting frequencies of 1.2 kilohertz or more in the case of a backward word; A decimator connected to the low pass filter and sampling back to 4 kHz when the filtered signal is input from the low pass filter; Connected to the decimator, each frequency band, and when a signal sampled from the decimator is input, passes only a frequency corresponding to the frequency band, and outputs a power measurement signal by measuring the power of the passed frequency. 6 band pass filters, And a decision logic receiving the power measurement signal from the six band pass filters and outputting digit information. The method of claim 1, When a signal sampled from the decimator is input to connect to the decimator and to forward the signal, a high pass filter is added to the bandpass filter after filtering a signal of 1.2 kHz or less. Device characterized in that.