KR200219773Y1 - Apparatus for fast data transfer - Google Patents

Abstract

The high-speed data transmission apparatus according to the present invention includes a compressor for compressing data to be transmitted at a constant efficiency, a transmission signal processing unit for converting the compressed digital data into a modulation, inverse Fourier transform, and an analog signal, and the transmission. And a received signal processor for demodulating, Fourier transforming, and converting the processed analog data into a digital signal, and a decoder for restoring the compressed data at a constant efficiency.

The high-speed data transmission apparatus according to the present invention compensates the transmission rate drop due to the structural problem of the channel caused by applying the general line installed for the conventional voice service to the high-speed communication as much as the efficiency of the compressor by applying the data compression and restoration technology. There is an advantage to provide a more extended transmission band to the network user.

In addition, this method can be applied not only to all modems using the multicarrier transmission method, but also to all high speed data transmissions in which the data rate is limited by the environment of the transmission channel.

Description

Apparatus for fast data transfer

The present invention relates to a high speed data transmission apparatus, and more particularly, to a high speed data transmission apparatus that compensates for a decrease in transmission speed due to an increase in transmission lines and users.

Today, the Internet population is skyrocketing. Accordingly, in the low-speed communication method using a conventional modem, private lines, home communication (Home Phone Line Network Alliance, HomePNA), asymmetric digital subscriber line (ADSL, hereinafter called 'ADSL'), cable modem, etc. The shift to high-speed communication networks has also increased rapidly. Of course, ultimately, it will be developed into home optical communication, wireless power and wireless communication, but it will take some time in the future, considering the current communication facilities based on the existing public switched telephone network (PSTN). The above leased line, home communication, ADSL, cable modem, etc. are the most suitable solution at present.

The high speed communication method such as ADSL, which enables high speed communication while using existing telephone lines as it is, improves its transmission speed by using a transmission method using up and down single carriers or using a multi-carrier transmission method. The multicarrier transmission method is an improved method of using one carrier each in the upper (mainly allocated to the transmitting part) area and the lower (mainly allocated to the receiving part) area, and transmits using a plurality of carriers. . By adopting the multi-carrier transmission method, it is possible to support various speeds according to various lines and to minimize the noise problem that is seriously generated during high speed communication. Discrete multi-tone (DMT, hereinafter referred to as 'DMT') transmission method, which is widely used in ADSL, is a signal-to-noise ratio for each band represented by the transmission channel environment by identifying the characteristics of the channel at the transmission initialization stage. According to the (Signal-to-Noise Ratio, SNR), the data rate that can guarantee a constant transmission performance is determined. This method greatly reduces noise during data transmission, but the total data rate is limited to the characteristics of the channel, and thus has a limitation in that it cannot exceed 8 Mbps in a twisted pair line, which is an ADSL transmission line. Due to the various channel characteristics, the data rate is much lower than the available 8Mbps data rate.

1 shows a schematic configuration diagram of a conventional high speed data transmission apparatus.

Referring to FIG. 1, a conventional multi-carrier high speed data transmission apparatus receives data to be transmitted and performs data allocation and quadrature amplitude / phase modulation (QAM, hereinafter referred to as 'QAM'). An encoder (11), an Inverse Fast Fourier Transform (IFFT, hereinafter referred to as IFFT) 12 for inverse Fourier transform in order to process a plurality of signals passing through the encoder, and Digital to Analog Converter (DAC), which converts a digital signal into an analog signal suitable for transmission on a transmission line (13), and removes noise generated through the above process. An outgoing filter 14 for transmitting a signal, a receiving filter 15 for removing noise from a signal received through a transmission line, and an analog for converting an analog signal into a digital signal An analog-to-digital converter (ADC, hereinafter referred to as 'ADC') 16 and a Fourier Transform (FFT, hereinafter referred to as 'FFT') which performs Fourier transform to divide one signal into several (17) and a decoder (18) for demodulating the modulated signal in its original state.

For reference, DMT is a line coding method of ADSL developed by Stanford University. Carrierless Amplitude / Phase Modulation (CAP), which uses a conventional single carrier, is called CAP. Unlike modulating data, the 256 equally divided bandwidths are combined with amplitude modulation and phase modulation. In other words, by using 256 QAM waves instead of one QAM wave in each band, a large amount of data can be sent simultaneously. For reference, the no-carrier in the CAP method does not mean that the carrier is not used, but rather that the carrier processing unit is integrated with the modulation and demodulation unit without independent carrier processing in the circuit. It is.

QAM method is a method of sending a large number of transmission waveforms per second and increasing the value of one waveform in order to speed up data transmission. How to increase. In other words, the two orthogonal carriers are amplitude modulated and then synthesized again. The expression is 2 ^N QAM, which means that N bits can be represented.

In the conventional multicarrier transmission scheme having such a configuration, as shown in FIG. 1, after the data to be transmitted is modulated at the sender (S 101), the multicarrier is inverse Fourier transformed so that the multicarrier can be processed in a batch ( S 102), the digital signal is converted into an analog signal according to the characteristics of the transmission line (S 103), and passes through an outgoing filter to remove noise (S 104).

In addition, at the receiving side, the data transmitted from the transmitting side is transmitted from the transmission line (S 105), and after the noise is removed through the filter (S 106), the data converted into an analog form is converted into a digital signal through an analog-to-digital converter. It is converted to (S 107). The digitally converted data is transformed into a form of the original multicarrier through Fourier transform (S 108) and demodulated by a decoder (S 109).

As described above, the conventional multi-carrier transmission method uses multiple carriers, so that the characteristics of the channel can be identified at the transmission initialization stage and suitable for producing a constant transmission performance according to the signal-to-noise ratio of each band indicated by the transmission channel environment. The data rate can be determined. This means that after connection, it is less affected by channel and noise, so it provides users with reliable connection status, but it also raises the problem that the high speed communication method cannot achieve the maximum speed that can be achieved.

The present invention was created to solve the above problems, and can provide a reliability while compensating for the slowdown due to channel characteristics while maintaining the reliability of the channel access for a high-speed communication transmission method that causes a slowdown. The purpose is to provide a high speed data transmission apparatus.

1 is a schematic configuration diagram of a conventional high speed data transmission apparatus.

Figure 2 is a schematic diagram showing a high speed data transmission apparatus according to the present invention.

3 is a schematic flowchart of a high speed data transmission according to the present invention;

<Explanation of symbols for main parts of the drawings>

11, 21a ... Encoder 12, 21b ... Inverse Fourier Converter

13, 21c ... digital-to-analog converter 14, 21d ... outgoing filter

15, 23a ... Receive filter 16, 23b ... Analog digital converter

17, 23c ... Fourier Converter 18, 23d ... Decoder

22 ....... Compressor 24 ........ Decoder

In order to achieve the above object, a high-speed data transmission apparatus according to the present invention includes a compressor for compressing data to be transmitted at a constant efficiency, and for converting the compressed digital data into a modulation, inverse Fourier transform, and an analog signal. And an outgoing signal processor, a received signal processor for demodulating, Fourier transforming, and converting the outgoing analog data into a digital signal, and a decoder for restoring the compressed data to a constant efficiency.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic diagram illustrating a high speed data transmission apparatus according to the present invention.

Referring to FIG. 2, a high speed data transmission apparatus according to the present invention includes a compressor 22 for compressing data to be transmitted at a constant efficiency, and converting the compressed digital data into a modulation, inverse Fourier transform, and an analog signal. An outgoing signal processor 21 for receiving, a received signal processor 23 for demodulating, Fourier transforming and converting the outgoing processed analog data into a digital signal, and a decoder for restoring the compressed data at a constant efficiency ( 24).

In more detail, the outgoing signal processing unit 21 allocates data to be transmitted for each band and encoder 21a for QAM modulation of the data allocated for each band, and collectively processing a plurality of signals passing through the encoder. IFFT 21b for inverse Fourier transform, DAC 21c for converting digital data into analog signal suitable for transmission in existing transmission line, and for removing noise generated through the above process. The receiving signal processor 23, which receives the data processed by the transmitting signal processor, processes the receiving signal 23a for removing noise from the signal received through the transmission line, The ADC 23b for converting an analog signal into a digital signal, the FFT 23c for Fourier transform for dividing a single signal into several, and the modulated signal It is composed of a decoder (23d) for demodulating state.

In the compressor 22, a compression encoding technique is used to remove unnecessary information included in the information in order to make the transmission speed as fast as possible in the digital transmission or to make the transmission possible in the shortest possible time. As described above, data compression refers to generating output data shorter than the original data length by eliminating redundancy among the valid information included in the target data and redundant redundancy as unnecessary space.

In general, this process is referred to as information source encoding or 'data compression', and a device that does this is called a compressor, and a device that does the opposite is called a decoder.

The data compressor method can be divided into a largely restorable method and a non-restorable method, which means that the original data can be obtained without loss of data from the compressed form, which is called a redundancy reduction method.

On the other hand, irreversible means that the original data cannot be reproduced from the compressed form, which is called entropy reduction.

The entropy reduction method is a method of reducing an information part among valid information and unnecessary redundancy included in data, and is generally used as a compression method of analog data regardless of whether the restored data such as voice or image is unclear to some extent. .

This method can obtain a relatively high compression rate compared to the redundancy reduction method, so that compression is performed in consideration of the meaning of the data or the context before and after a specific application such as image transmission.

Therefore, in view of the above, most digital data compressor methods handled in information and communication are intended to reduce redundancy.

The redundancy reduction technique can be classified into several types according to the source data and the length of the code after compression.In addition, the data compression method can be classified according to various classification criteria. One run-length coding method for physically compressing consecutively repeated characters in data, a difference mapping method using a difference between adjacent data values, and a frequently occurring pattern or character block Pattern Substitution, which is assigned as the compression code of.

In addition, the Huffman compressor method assigns short codes to frequently appearing characters and long codewords to infrequently appearing data, the modified Huffman compressor method used as standard compressor method in facsimile communication, and dynamic Huffman. The lempel-ziv-welch (LZW) compressor method, which performs compression by generating a pattern from data without using the statistical properties of source data, including sign, is the most widely used today.

The encoder (21a) is a serial-to-parallel converter for converting a constant multiple times compressed serial data in parallel, I, Q signal generator for dividing the signal converted in parallel in the serial-to-parallel converter into a phase and an amplitude portion, and A 2 to L level converter for amplitude modulation of the signal divided into phase and amplitude, a low pass filter to remove noise generated through the above steps, and a separated phase signal and amplitude signal are not canceled when combined. It consists of a phase shifter to make a 90 ° transition (orthogonal) to prevent it.

Next, a process of a multicarrier transmission method using data compression and data reconstruction in ultra high speed communication according to the present invention having the above configuration will be described with reference to FIG. 3.

3 shows a schematic flowchart of a high speed data transmission according to the present invention.

In the case of ADSL, which is an asymmetric digital subscriber line, data to be sent are coming in at a rate of N × 32kbps, and these data are input to the data compressor (S 201). The input data is compressed by a constant multiple by the data compressor (S 202), which is allocated and modulated by the data allocation calculated for the transmission performance required for the band in the encoder (S 203), and then inversed by the IFFT. The batch process is facilitated through a Fourier transform process (S204).

The data received from the transmitter is converted into a frequency domain through the FFT at the receiver (S 205), first decoded and demodulated by the decoder according to the amount of data allocated to each band (S 206), and then input to the data decoder. Enter (S 207). The compressed data is restored to the original data by a certain number inversely in the data decoder (S208). The compression and reconstruction values of the constant multiple are determined by the compression performance of the compressor itself regardless of the characteristics of the multicarrier transmission line.

As a result, if the transmission rate that can be transmitted through the transmission line channel was N x 32 kbps, the transmission rate of data that can be transmitted from the transmitting side to the receiving side through this channel increases by a constant multiple x N x 32 kbps.

On the other hand, in the example of the CAP using one carrier each up and down, the implementation method is simpler than that of DMT, but the reliability of the channel is lower than that of DMT. There is a problem with applying compression and decompression. However, as technology advances and supplements in the future, the application of compression and reconstruction techniques to a multicarrier method can be extended to a single carrier.

As described above, the high-speed data transmission apparatus according to the present invention is to reduce the transmission speed due to the structural problem of the channel caused by applying the general line installed for the conventional voice service to high-speed communication as the data compression and restoration technology is applied. By compensating for the efficiency, it has the effect of providing the network user with an extended transmission band. In addition, this method can be applied not only to all modems using the multicarrier transmission method, but also to all high speed data transmissions in which the data rate is limited by the environment of the transmission channel.

Claims (1)

Compressor for compressing the data to be transmitted with a certain efficiency, An outgoing signal processor for converting the compressed digital data into a modulation, inverse Fourier transform, and an analog signal; A reception signal processor for converting the outgoing processed analog data into a demodulation, a Fourier transform, and a digital signal; A high speed data transmission device comprising: a decoder for restoring compressed data at a constant efficiency.