CN-116015353-B - Enhanced double-stranded copper wire transmission system and implementation method

Abstract

The invention discloses an enhanced double-stranded copper wire transmission system and an implementation method, wherein the enhanced double-stranded copper wire transmission system comprises an FPGA and an analog front end matched with the FPGA, the FPGA is configured to comprise a framing/de-framing unit, a digital front end unit and an SOC subsystem, the framing/de-framing unit is connected with network equipment at a public network or local area network end through an interface unit, the digital front end unit is connected with the analog front end and used for realizing PAM and CAP modulation and demodulation, the SOC subsystem is respectively connected with the framing/de-framing unit and the digital front end unit so as to complete link establishment and state management, the SOC subsystem adopts an embedded core, and a UART serial port of the embedded core is a management channel under an SDSL technology and an SHDSL technology. The invention provides an enhanced double-stranded copper wire transmission system and an implementation method thereof, which adopt a method of channel compatibility and multiplexing of algorithm function modules, not only support two transmission technologies of SDSL and SHDSL, but also break through the limitation of the ITU-G.991.2SHDSL standard by adopting a method of spread spectrum, so that the highest transmission rate is not lower than 20480kbit/s, and simultaneously meet the application requirements of users for low speed, long distance and short distance and high bandwidth.

Inventors

• XIAO DONGHAI
• YAN XINGMAO
• SHEN QIUXU
• LIU YANBING
• GAO ZHAN
• WEI TAO
• SONG SONG

Assignees

• 四川灵通电讯有限公司

Dates

Publication Date

20260512

Application Date

20221129

Claims (5)

1. 1. An enhanced twisted pair copper wire transmission system comprising an FPGA and an analog front end mated thereto, the FPGA configured to include: The framing/de-framing unit is connected with the network equipment of the user side through the interface unit; The digital front end unit is connected with the analog front end and used for realizing PAM and CAP modulation and demodulation; The SOC subsystem is respectively connected with the framing/deframer unit and the digital front-end unit to finish link establishment and state management; the analog front end is configured to include: a receiving unit and a transmitting unit which are in communication connection with the twisted copper wires; The FPGA is also connected with a configuration chip for storing FPGA software codes and a clock unit for providing clock signals; the analog front end is connected with a twisted copper pair wire through a matched transformer; The SOC subsystem is configured to adopt an embedded core, and a UART serial port of the embedded core is a management channel under the SDSL technology and the SHDSL technology; The SOC subsystem of the enhanced double-stranded copper wire transmission system realizes the communication channel switching under the SDSL and SHDSL technologies through the management of configuration parameters and the function module corresponding to the digital front-end multiplexing algorithm, and completes the data communication or handshake link establishment; when the communication channel is switched, the management of the configuration parameters comprises the following steps: Based on the selection of SDSL and SHDSL technologies, corresponding parameters of the functional module are adjusted through the digital front end; Different transmitting powers are preset for the SDSL and the SHDSL respectively, and the FPGA is used for matching the corresponding transmitting power based on the selection of the SDSL and the SHDSL, so that the adaptation of the transmitting power during the switching of the communication channels is completed; the digital front end is configured to adopt a DSP computing unit, and the multiplexing flow of the equalizer module, the interpolation filtering module and the noise shaping filtering module in the digital front end multiplexing algorithm is configured to comprise: s1, selecting and data rate according to different modes by the embedded kernel, and controlling a DSP computing unit to configure initial coefficients of a filter; s2, starting an error calculation program to perform iterative operation by the DSP calculation unit according to the input data stream; And S3, when the error reaches a specified value, the DSP computing unit writes the converged filter parameters into a parameter configuration interface of the filter to complete parameter configuration under different technical systems, so that function multiplexing of the functional module under different systems is realized.
2. 2. The enhanced twisted pair copper wire transmission system of claim 1, wherein the receiving unit is configured to include: a receiving and amplifying circuit connected with the transformer side; The receiving and amplifying circuit is connected to carry out analog-to-digital conversion on the amplified signal and send the signal to an analog-to-digital converter ADC of the digital front-end unit; the transmission unit is configured to include: A digital-to-analog converter DAC connected to the digital front end unit; A line driving module for sending the signal received from the DAC to the transformer side; the amplifying circuit is connected with the ADC, and the DAC is connected with the line driving module through a line driving module; And a resistor is arranged between the line driving module and the transformer, and the output end of the line driving module is connected to the receiving amplifying circuit.
3. 3. The enhanced twisted pair copper wire transmission system of claim 2, wherein the signal bandwidth of the ADC, DAC, low pass filter is configured to be greater than a maximum analog bandwidth required for 20480kbit/s and the signal to noise ratio of the device is greater than the signal to noise ratio required for mtc-PAM; The transmitting power of the analog front end is less than or equal to 14.5dBm.
4. 4. The enhanced twisted pair copper wire transmission system of claim 1, wherein the digital front end algorithm multiplexed functional module is configured to include: The system comprises a scrambling and descrambling module, a coding and decoding module, a precoding module, an echo cancellation module, an equalizer module, an interpolation filtering and noise shaping filtering module which are commonly used in SDSL and SHDSL technologies; And an IQ filter unique to SDSL to accomplish multiplexing of functional blocks in SDSL and SHDSL technologies through a relatively fixed structure.
5. 5. A method of implementing the enhanced twisted pair copper wire transmission system of claim 1, wherein the process of implementing subscriber a and subscriber B chaining and communicating through the enhanced twisted pair copper wire transmission system is configured to include: The method comprises the steps that firstly, an FPGA on a user A side receives service data sent by a user A through an interface unit, frames, codes and modulates the received signals and sends the signals to an analog front end of a local end; Step two, the analog front end of the user A carries out digital-to-analog conversion, shaping and filtering and signal amplification on the signal received from the FPGA and then sends the signal to the twisted copper wire; Step three, the analog front end of the user B receives a message from the twisted copper pair wire, counteracts the local echo signal and amplifies the received signal through a receiving and amplifying circuit so as to amplify the amplitude of the received signal to be within the receiving level range of the ADC, and after a sampling clock outside a Nyquist first interval of the received signal is filtered by a low-pass filter, the received signal is digital-to-analog converted through the ADC and then is sent to the FPGA of the user B; step four, the FPGA of the user B demodulates and deframes the received signals and then sends the signals to the user B; Step five, the user B adopts the same mode to simultaneously send the service data of the local terminal to the user A, and the user A receives the service data; Step six, before the user A and the user B transmit and receive service data, the SOC subsystem of the enhanced double-stranded copper wire transmission system realizes the switching of communication channels under the SDSL and SHDSL technologies through the management of configuration parameters and the function modules corresponding to the digital front-end multiplexing algorithm, and completes data communication or handshake link establishment through the step one to the step five.

Description

Enhanced double-stranded copper wire transmission system and implementation method Technical Field The invention relates to the technical field of double-stranded copper wire transmission. More particularly, the invention relates to an enhanced twisted pair copper wire transmission system and an implementation method. Background At home and abroad, transmission technologies based on twisted copper wires mainly comprise SDSL, SHDSL, ADSL & lt 2 & gt+, VDSL2, G.hn, G.fast and the like. The HDSL standard (G.991.1) was approved by ITU-T in 1998, supporting symmetric transmission. The CAP modulation mode is adopted, so that an SDSL transmission technology is extended, 2048kbit/s rate is supported, the SDSL transmission technology is generally applied to data transmission within a range of 12 km, and a chip based on the SDSL transmission technology is stopped. In 2001 ITU-T approved the SHDSL standard (g.991.2), supporting symmetric transmission. Because SHDSL adopts TC-PAM modulation mode with excellent performance, the transmission spectrum is compressed, the anti-noise performance is improved, and the transmission distance is prolonged, so that compared with ADSL and HDSL technologies, the method has obvious distance advantages. At present, the SHDSL access technology of G.991.2 can realize symmetric data transmission with the highest rate of 15Mbit/s, is generally applied to data transmission within the range of 12 km, and a chip based on the technology is about to be stopped. ITU-T in 2003 supported asymmetric transmission by the new generation of adsl2+ standard (g.992.5). ADSL2+ adopts DMT modulation mode, supports all techniques of ADSL2, widens the line frequency band to 2.2MHz, increases the maximum subcarrier number to 512, increases the highest downlink rate to 24Mbit/s, and is fully compatible with ADSL and ADSL2 standards. The new add-on annex M in the ADSL2+ standard increases the uplink bandwidth by means of dynamic frequency adjustment, and the maximum uplink rate which can be provided theoretically is 3.5Mbit/s. Typically for data transmission over a 3 km range. ITU-T in 2005 passed the VDSL2 standard (g.993.2) supporting both symmetric and asymmetric transmission modes. The VDSL2 determines DMT as a unique modulation mode, so that intercommunication among VDSL2 devices of different manufacturers is realized, meanwhile, the VDSL2 expands a line Frequency band to 30MHz, the maximum uplink and downlink rates respectively reach 100Mbit/s, and technologies such as time domain equalization (TEQ), echo Cancellation (EC), frequency spectrum Notch (Frequency Notch), uplink power reduction (UPBO) and the like are added, so that transmission performance and anti-interference capability are enhanced. Typically for data transmission over a range of 1 km. In 2010, ITU-T promulgates G.hn standard (G.9960), adopts OFDM modulation mode, the line frequency band reaches 100MHz, supports 4096-QAM modulation mode, and the maximum bidirectional transmission rate reaches 1Gbit/s. G.hn supports three transmission media, telephone lines, power lines and coaxial cables, which are home networking technology standards commonly used for data transmission over a range of 1 km. ITU-T promulgates the g.fast standard (g.9701) in 2020, and upstream and downstream rates can be allocated as needed. The fast adopts a DMT modulation mode, the line frequency band is expanded to 106MHz, and possibly 212MHz, and the fast is compatible with ADSL < 2+ > and VDSL < 2 >, can provide a bidirectional transmission rate of up to 1Gbit/s, and is generally applied to data transmission in the range of 200 meters. Because of the unique advantages of symmetrical service, long communication distance, strong anti-interference capability and the like of the SDSL and the SHDSL, the technology is more suitable for long-distance communication and partial private network communication than the technology of ADSL2+, VDSL2, G.hn and G.fast, and the technology of the SDSL and the SHDSL has longer continuity in the use of the private network communication, and the chip of the SDSL is stopped when the chip of the SDSL is stopped and the chip of the SHDSL is about to be stopped, and the continuous ordering requirement cannot be met. Disclosure of Invention It is an object of the present invention to address at least the above problems and/or disadvantages and to provide at least the advantages described below. The invention aims to provide an enhanced double-stranded copper wire transmission system and an implementation method, wherein a reconfigurable FPGA+analog front-end hardware system is established, a CAP and PAM fused software code is designed, two technologies of SDSL and SHDSL are supported, the line frequency spectrum is further expanded, and service data with the highest speed not lower than 20480kbit/s is transmitted on a pair of double-stranded copper wires. To achieve these objects and other advantages and in accordance with the purpose of the in