New signal processing techniques can double the data transmission distance on fiber optic systems

A new method of signal processing via fiber optic cable has been successfully developed by researchers and this method can significantly increase the error-free data transmission distance by underwater cable. without the need for signal amplifiers.

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New signal processing techniques increase the capacity of optical fiber transmission lines

It is known that in addition to correcting data errors that are being transmitted through cables, the new technology can also increase the capacity of all fiber optic lines.

To meet the growing demand for high-speed Internet, researchers have focused on increasing the number of available frequency channels in which data is encoded as a transmitted light signal instead of installation of fiber optic cables. This has been done through a number of studies such as the Center's new data encryption technology of ultra-high bandwidth devices for optical systems (CUDOS) of Australia or Fraunhofer's innovative infrared technology. as many methods are designed to overcome non-linearity when the signal is transmitted too long in fiber optic cable.

However, even though the above techniques have reached the limit of the ability to transmit and receive light without causing interference with adjacent light signals, the data still suffers from a defect error (distortion error ).

To solve this problem, researchers at the University of London (UCL) have created a method to prevent interference by using a frequency set encoded by amplitude, phase and special frequencies to Create a high quality optical signal and extremely large capacity.

In more detail, the team used a laser to create an optical transport element and put the element through a comb generator - this machine can generate many early signals. on the air conditioner and the output signal of the spectral display on the analytical screen is quite similar to the comb teeth. From the transmitter, the element forms 7 equally spaced frequencies in the form of QAM, namely a 16 QAM super channel (QAM - Quadrature Amplitude Modulation - modulating the quadrature amplitude or modulating perpendicular amplitude). The super-channel signal is then fed to one end of the fiber optic cable and collected at the other end with a high-speed receiver. Using new signal processing techniques developed specifically by the research team, data signals transmitted in all received channels remain in the same quality and are not error-prone.

Dr. Robert Maher from the Department of Electrical and Electronic Engineering at UCL said: "By eliminating the interaction between optical channels, we were able to double the distance the signal could be transmitted. lead without errors, from 3190 km to 5890 km, this is also the largest distance achieved on the system architecture, the challenge here is to find a technique to simultaneously capture a group of optical channels known by the name of a super channel with a single receiver. "

Using 70 GHz bandwidth is available on an optical super channel, the maximum transmission distance that the system achieves in the test is 5890 km. This is also the largest distance ever achieved when exploiting digital back-propagation techniques - a technique that compensates for all the errors of cable in optical transmission systems. digital reverse transmission algorithm).

Following success in the testing of the new method, current researchers are intending to integrate these techniques into thicker densities that are often used in transmission lines like cable TV. algorithm, modem and Ethernet connection.

"We are excited to announce that this important finding will significantly improve fiber-optic transmissions. Our approach will increase transmission efficiency," said team member Polina Bayvel . The data, nearly doubling the reach and potential transmission distance, will save a lot of costs on the latest commercial fiber optic cable systems, one of the biggest challenges we have to facing how to remain connected to the growing Internet demand and overcoming the capacity limits of fiber optic cables is a way to confront this challenge. "