INVARIANT METHOD OF INFORMATION TRANSMISSION IN FIBER-OPTIC TRANSMISSION SYSTEMS

Abstract

We have synthesized a method of controlling the distortions introduced by fiber-optic communication lines. This method is based on the use of invariant equality. Its main technical characteristics have been determined.

Full Text

Classical AM Modulation in fiber-optic transmission systems (FOTS) is used to transfer information signaling in most cases. The probability of erroneous reception in regenerators is 10–10, according to the recommendations of the International Telecommunication Union (ITU) [1]. More recent ITU [2] recommendations have proposed to apply device error protection (RCD) the performance of which is based on a special transmission signal coding by means of cyclic codes. It is difficult to create a residual operating in real time at a speed of 10 Gb / s and more. Meanwhile, the reduction of error probability can be achieved in other ways. One is suggested below. We have the FOTS (fig. 1). A laser is used as a transmitter. A photo detector is used as a receiver. The second window of transparency is used to send the information signal. The information signal transmission algorithm must be synthesized based on the invariant method of information processing. Fig. 1 shows the structure of FOTS, which includes the transmitting and receiving devices and the fiber-optic transmission. It should be noted that the cross-cutting path of the FOTS at the second window of transparency [3] is linear, provided the power output of the transmitter to not exceed the permissible value of 1 mW. The Z-transform signal reception Y (Z) on the output of the FPU will be equal to (for i-volume processing unit): i ( ) ( ) 0 ( ) 1 ( ) 2 ( ) i Y Z = ⎡⎣G Z ⋅H Z ⋅H Z ⋅H Z ⎤⎦ , (1) where Gi(Z) – is the Z-transform of the signal transmission at the i-volume processing unit; H0i(Z) – the transfer characteristic of the signal shaper at the i-volume unit; H1i(Z) – is the transfer characteristic of fiber-optic transmission at the i-volume unit; H2i(Z) – the transfer characteristic of the unit (FPU) on the i-unit.