KR100243692B1 - Analogue front end circuit over telephone lines for high bit rate data transfer - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to an analog termination device for high speed data transmission and reception on a telephone line.

2. The technical problem to be solved by the invention

An object of the present invention is to provide an analog termination device that can be used simultaneously for an optical termination device and a subscriber station device by replacing a filter by configuring a circuit having a common structure.

3. Summary of Solution to Invention

In the present invention, the existing high speed subscriber analog termination device using a telephone line is composed of circuits different from the network side and the subscriber side, so that the gain of the analog signal received from the subscriber side is adjusted using a programmable gain adjuster and the same gain adjustment parameter is adjusted. On the other hand, the error of signal interference on the line is minimized by adjusting the reception gain with the programmable gain amplifier on the receiving side.

4. Important uses of the invention

The present invention is used for the optical termination device and subscriber terminal device on the telephone line.

Description

Analog termination device for high speed data transmission and reception on telephone line

The present invention relates to an analog termination device for transmitting and receiving data between a subscriber station device and an optical termination device in a subscriber service network for accommodating Internet service and video service using a conventional telephone line.

Currently, services available to general subscribers include telephone service using double shielded line, CATV service using coaxial cable, and internet service using existing telephone line. However, each service uses different line and high speed and high capacity. Since data service is impossible, there is a problem such as a delay in service. In order to solve these problems and to accommodate Internet service, real-time video service, telemedicine service, and distance education service in one integrated network to operators or general subscribers, a broadband integrated information communication network (B-based) based on asynchronous transmission mode (ATM) ISDN: Broadband Integrated Services Digital Network This asynchronous transfer mode (ATM) -based broadband Telecommunications Network has the capacity to support high-capacity, high-speed services that are incomparable with existing networks, so it is possible to integrate not only existing services but all future services. Is getting more and more attention as the network of the future.

However, such a broadband integrated telecommunication network has a disadvantage in that it cannot use an Ethernet line, which is widely used for transmitting and receiving data in a conventional telephone line and a workplace, by using an optical cable and a category-5 double shielded line as a basic transmission line. Therefore, since it takes a long time to install the optical lines in the general home and each workplace, it is necessary to provide a service using the lines already widely installed.

In addition, the existing VDSL analog terminator is composed of different circuits between the network side and the subscriber side, and adjusts the gain of the analog signal received from the subscriber side using a programmable gain adjuster. Since the transmission gain to the network is adjusted using the adjustment parameter, it may not cause a problem when the transmission / reception signals are the same and the interference between each other is the same.However, in the case of the same signal, one signal is better than the other signal. Since a lot of interference can be applied, there is a problem that the probability of serious signal error on the receiving side increases.

Accordingly, the present invention provides a subscriber station apparatus in an optical termination unit and a subscriber station apparatus, which are devices for providing high-speed real-time service and large-capacity data service by using existing telephone lines to each subscriber. The purpose of the present invention is to provide an analog terminal device having a common structure for simultaneously transmitting and receiving a modulated signal from a subscriber terminal device to an optical terminal device and to simultaneously use the optical terminal device and the subscriber terminal device by simply replacing a filter. have.

1 is a block diagram of a subscriber service network using a general telephone line.

2 is a block diagram of an optical termination device and a subscriber station device using a double shielded line to which the present invention is applied.

3 is a temporary configuration diagram of an analog termination device according to the present invention.

* Explanation of symbols for the main parts of the drawings

310: transmitter 320: frequency processor

330: receiver

The present invention for achieving the above object, in the analog terminal device for transmitting and receiving data in the subscriber service network using a telephone line, interference between frequencies generated by transmitting and receiving signals having different frequency bands on the same telephone line Transmission means for filtering and transmitting the transmission frequency band input from the outside to remove the transmission; The frequency of the transmission modulation signal input from the transmitting means is separated and transmitted to another analog terminal device through a telephone line, and the telephone signal received from the other analog terminal device through a telephone line is transmitted to an external telephone. Frequency processing means for separating and transmitting the frequency of the received modulated signal inputted from the analog terminator via a telephone line; And receiving means for filtering the received frequency band of the received modulated signals input from the frequency processing means to pass and adjusting the received gain to transmit the received gain to remove the signal error.

Hereinafter, with reference to the accompanying drawings will be described an embodiment according to the present invention;

1 is a block diagram of a subscriber service network using a general telephone line, including: an access node 12 for providing a single optical line by integrating various types of services, an internet service 14 connected to the access node 12, The service provider 13 composed of the video service 15 and the asynchronous transfer mode switch 16 and the like terminate the service delivered via the optical line from the access node 12 and use the telephone line which is an existing subscriber line. An optical termination device 11 for delivering a service to each subscriber terminal device 10, and a subscriber terminal device 10 connected to the optical termination device 11 by a telephone line.

The optical end device 11 for delivering a service to a general subscriber using a telephone line modulates the service delivered from the access node 12 using the optical line into a signal suitable for the telephone line, thereby providing each subscriber terminal device 10 with an optical line. The service data is transmitted to the access node 12 after multiplexing service data requested to be transmitted from each subscriber station device 10.

In order to transmit and receive data between the optical termination device 11 and each subscriber station device 10 using a pair of telephone lines, a modulation method using different frequency bands between the transmission and reception data is required, and the modulation signal is filtered. In addition to amplifying, a circuit for separating and transmitting frequency bands is required.

2 is a block diagram of an optical termination device and a subscriber station device using a double shielded line to which the present invention is applied.

The optical termination device 11 transmits and receives an external asynchronous transfer mode (ATM) processing unit and an asynchronous transfer mode (ATM) cell, and a network-side physical layer transmission converging unit 24 for transmitting and receiving a physical layer frame with the subscriber station apparatus 10. In addition, a network transmission modulator 22 for modulating the bit stream transmitted from the network side physical layer transmission converging unit 24 and transmitting it to the subscriber station device 10 and the power required to transmit data to the subscriber station device 10 is provided. Compensation for signal attenuation so that the data is transmitted, the data transmitted from the network transmission modulator 22 is transmitted to the subscriber station apparatus 10, and the signal transmitted from the subscriber station apparatus 10 is amplified to be recognized by the network reception demodulator 23. The number of network-side physical layer transmissions after receiving and demodulating the modulated signal requested to be transmitted by the network-side analog termination device 21 and the subscriber station 10 through the network-side analog termination device 21 And a network receiving demodulator (23) for transmission to the unit 24.

The subscriber station apparatus 10 transmits the signal transmitted from the network side to the subscriber reception demodulator 26 by filtering only the necessary band and transmits the modulated signal received from the subscriber transmission modulator 27 to the network side. ), A subscriber reception demodulator 26 for receiving and demodulating a signal received from the network side through the subscriber side analog termination device 25, and modulating the data to be transmitted by the subscriber side to the network side through the subscriber side analog termination device 25. And a subscriber side physical layer transmit convergence unit 28 for connecting with the subscriber.

3 is a block diagram of an embodiment of an analog termination device according to the present invention.

The transmitter 310 is a digital-to-analog converter 311 for converting a digital transmission modulated signal input from an external device into an analog signal, and an analog output from the digital-to-analog converter 311 to attenuate long-distance transmission and errors on a line. A transmission band pass filter 313 and a transmission band pass filter 313 which pass only necessary frequency bands of the amplified signal output from the transmission signal amplifier 312, a transmission signal amplifier 312 for converting the signal into a differential signal after amplifying the signal; And a line driver 314 for amplifying and outputting the signal output from the line to the line, and a protection circuit 315 connected to the line to protect the internal circuit from unnecessary external voltage drops.

The frequency processor 320 induces the received modulated signal received through the telephone line, and transmits the received modulated signal to the 4KHz to 30MHz bandpass filter 322 and the 4KHz low frequency bandpass filter 323, and the 4KHz to 30MHz bandpass filter 322. 4KHz ~ that is required among the transformer 324 and the received modulation signal output from the transformer 324 for transmitting the modulated signal output from the transformer and the telephone signal output from the 4KHz low frequency band filter 323 to the external device through the telephone line. 4KHz to 30MHz bandpass filter which passes only the 30MHz frequency band and outputs the modulated frequency separator 321 and passes only the required 4KHz to 30MHz frequency band among the transmitted modulated signals output from the modulated frequency separator 321 to the transformer 324 ( 322) and outputs to the external telephone by passing only the frequency band of the required telephone signal among the received modulated signals output from the transformer 324 to the external telephone. 4KHz low-frequency filter 323 to pass only the frequency band of the telephone signal of the signal output from the output to the transformer 324, the frequency of the transmission modulation signal output from the transmitter 310 by separating the 4KHz ~ 30MHz bandpass filter (322 And a modulated frequency separator 321 for separating the frequency of the received modulated signal output from the 4 KHz to 30 MHz band pass filter 322 and outputting the frequency to the receiver 330 through a line.

In addition, the receiving unit 330 is connected to a line for connecting to the modulation frequency separator 321 and is output from the protection circuit 338 and the modulation frequency separator 321 for protecting the internal circuit from unnecessary external voltage drops. A line receiver 331 for receiving a modulated signal through a line and compensating for signal attenuation, a reception band pass filter 332 and a reception band pass filter 332 for extracting only a received modulated signal component among signals output from the line receiver 331. A single output from the differential / single signal converter 333 and a differential / single signal converter 333 for converting the differential receive modulated signal output from the signal into a single receive modulated signal for use as an input of the voltage regulation gain controller 334. Voltage-adjusted gain controller 334 for controlling the gain by amplifying the received modulated signal according to the control voltage output from the digital-to-analog converter 337. ), Which is used as a gain control variable of the analog-to-digital converter 335 and the voltage-adjusted gain controller 334, which converts the received analog-modulated signal output from the voltage-adjusted gain controller 334 to a digital received-modulated signal and outputs it to an external device. A gain variable controller 336 that selects one of an output of the analog / digital converter 335 and an external processor data input, and a digital signal output by converting a digital signal output from the gain variable controller 336 into an analog signal. A digital-to-analog converter 337 for converting to the control voltage required by 334 is provided.

Hereinafter, the operation of the analog termination device according to the present invention will be described.

First, referring to the operation of the transmitter 310, the transmission modulated signal requested for transmission by the network transmission modulator 22 of the optical termination device 11 or the subscriber transmission modulator 27 of the subscriber station apparatus 10 is n-bit. It is expressed as a digital value of, and conversion to an analog signal is required to carry it on a line. The digital-to-analog converter 311 converts a multi-bit digital signal into a corresponding analog signal, and the output of the analog signal is a current driving signal, which is required to be converted into a voltage according to the current using a termination resistor.

The analog signal output from the digital-to-analog converter 311 is transmitted to the input of the transmission signal amplifier 312, amplified by the voltage required for line transmission, and converted into a differential signal convenient for long-distance transmission and error attenuation on the line, and then passes through the transmission band. In filter 313 only the major frequency band of the signal is separated. The transmission band pass filter 313 is for removing interference between frequencies generated by transmitting and receiving signals having different frequency bands on a pair of telephone lines, and the harmonics of the transmission modulated signal are the frequencies of the received modulated signals. This eliminates the problem of interference between two signals that becomes difficult to separate.

The signal passing through the transmission band pass filter 313 is transmitted to the line driver 314 to be amplified to transmit data on the line, the amplified signal of the optical termination device 11 through the frequency processor 320 The data is transmitted to the subscriber reception demodulator 26 of the network reception demodulator 23 or the subscriber station apparatus 10. The protection circuit 315 consists of a plurality of diodes to function to protect the internal circuits from voltage drops and lightning strikes from external power lines.

Next, referring to the operation of the frequency processor 320, the modulation frequency separator 321 transmits a transmission modulated analog signal to the band pass filter 322, and also receives a modulation modulated analog that requires transmission from the band pass filter 322. It provides a function for transmitting the signal to the receiver 330, respectively, the band pass filter 322 separates only the frequency component of the transmission and reception modulation signal, the low frequency band filter 323 separates only the frequency band of the telephone signal. Therefore, the signal received from the telephone line is simultaneously transmitted by the transformer 324 to the band pass filter 322 and the low frequency band filter 323, but in the case of the telephone signal to the external telephone only by the low frequency band filter 323. The received modulated signal is transmitted by the band pass filter 322 only to the receiver 330 via the modulation frequency separator 321.

Next, referring to the operation of the receiver 330, the received modulated signal transmitted from the frequency processor 320 extracts only the main band component from the receive band pass filter 332 after the signal attenuation is compensated for in the line receiver 331. And the output of the differential / single signal converter 333 is applied to the input of the voltage regulation gain controller 334 and amplified to the voltage waveform required by the analog / digital converter 335. do. The voltage regulation gain controller 334 is a device for controlling the gain of the input signal as a function of voltage, and the received analog modulation signal waveform which is the output waveform signal of the voltage regulation gain controller 334 to the output voltage of the digital / analog converter 337. To control.

Looking at the process of controlling the received analog modulated signal using the voltage adjustment gain controller 334, the gain variable controller 336 is a digital received modulation signal output from the analog-to-digital converter 335 and the external processor gain control signal After selecting one to generate a digital variable control signal, the digital variable control signal is converted into an analog output signal corresponding to digital using a digital / analog converter 337 to generate a control voltage, and a voltage adjustment gain controller 334. ) Uses the control voltage as a gain adjuster to produce a gain-adjusted analog receive modulated signal.

The control voltage used to output the received analog modulated signal at the voltage adjusting gain controller 334 is selected from one of a digital received signal output from the analog / digital converter 335 or a signal generated by the control of an external processor. When deriving the control voltage using the digital received signal as a variable, after setting a certain threshold value, the average value per unit time is calculated, if the threshold value is larger than the average value, the amplification is adjusted and the control voltage is attenuated if it is smaller. When the control voltage is generated by the processor, the processor statistically commands the signal amplification and attenuation according to the bit error rate of the received signal. Gain Adjustment The analog receive modulated signal is adjusted to the input signal level required by the analog / digital converter 335 via an AC coupling circuit and then converted by the analog / digital converter 335 into a digital receive modulated signal. The signal is transmitted to the network reception demodulator 23 of the optical termination device 11 or the subscriber reception demodulator 26 of the subscriber station 10.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited to the drawing.

As described above, the present invention transmits high-speed data of several tens of megabits from an optical end device to a subscriber terminal, and transmits data over a telephone line in a subscriber transmission device capable of transmitting a maximum of several megabits from the subscriber terminal to the optical end device. In addition, it can be used for all devices that transmit and receive data between the optical termination device and the subscriber terminal using the existing telephone line, and can be used by replacing only the frequency band used in all access networks or subscriber networks using the telephone line.

Claims (4)

An analog termination device for transmitting and receiving data in a subscriber service network using a telephone line, Transmitting means for filtering and transmitting a transmission frequency band input from the outside to remove interference between frequencies generated by transmitting and receiving signals having different frequency bands on the same telephone line; The frequency of the transmission modulated signal input from the transmitting means is separated and transmitted to another analog terminal device through a telephone line, and the telephone signal received from the other analog terminal device through a telephone line is transmitted to an external telephone. Frequency processing means for separating and transmitting the frequency of the received modulated signal inputted from the analog terminator via a telephone line; And Receiving means for filtering the received frequency band of the received modulated signal input from the frequency processing means to pass and adjust the reception gain to transmit to the outside to eliminate signal errors Analog termination device made, including. The method of claim 1, The transmission means, First digital / analog conversion means for converting a digital transmission modulated signal input from an external transmission modulator into an analog signal; Transmission signal amplifying means for amplifying an analog signal input from said first digital / analog converting means; Transmission band pass filtering means for passing a transmission frequency band among the amplified signals inputted from the transmission signal amplifying means; Line driving means for amplifying the signal input from the transmission band pass filtering means for transmission on the line and then outputting the signal on the line; And First protection means connected to the line to protect the internal circuit from unnecessary external voltage drops Analog termination device made, including. The method according to claim 1 or 2, The frequency processing means, A transformer for inducing and outputting a received modulated signal received through the telephone line from the other analog terminator, and transmitting the transmitted modulated signal and the telephone signal to the other analog terminator via a telephone line; Band pass filtering means for passing a predetermined frequency band among the received modulated signals inputted from the transformer and outputting it, and passing the predetermined frequency band among the input modulated signals inputted to the transformer; Low frequency band filtering means for passing the frequency band of the telephone signal among the received modulated signals input from the transformer to an external telephone, and passing the frequency band of the telephone signal among the signals input from the external telephone to output to the transformer; And Modulation for separating the frequency of the transmission modulated signal input from the transmitting means to the band pass filtering means, and separating the frequency of the received modulated signal input from the band pass filtering means to output to the receiving means through a line Frequency separation means Analog termination device made, including. The method of claim 3, wherein The receiving means, Second protection means connected to a line for connecting with the modulation frequency separation means to protect an internal circuit from an unnecessary unnecessary voltage drop; Line receiving means for receiving a received modulated signal input from said modulated frequency separation means to compensate for signal attenuation; Reception band pass filtering means for band-passing a received modulated signal of the signals input from said line receiving means; Differential / single signal conversion means for converting the differential received modulated signal input from said receive band pass filtering means into a single received modulated signal; Voltage regulation gain control means for controlling gain by amplifying a single received modulated signal input from said differential / single signal conversion means according to a control voltage; Analog / digital converting means for converting a received analog modulated signal input from the voltage adjusting gain control means into a digital received modulated signal and outputting it to an external receive demodulator; Gain variable control means for selecting one of an output of said analog / digital conversion means and an external processor data input for use as a gain control variable of said voltage regulation gain control means; And Second digital / analog conversion means for converting a digital signal input from the gain variable control means into an analog signal and outputting a control voltage to the voltage regulation gain control means; Analog termination device made, including.

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