RESEARCH OF THE PHASE DIFFERENCE IN OPTOELECTRONIC AND MICROWAVE INTERFACE MODULES OF COMMUNICATION SYSTEMS WITH MULTILEVEL MODULATION FORMATS

Abstract

The purpose of the study is to calculate and design the device that measures the phase differences of signals, with the ability to receive control commands and transmit the results via a high-speed Ethernet interface. Any modern measuring device of the optical or ultrahigh frequency (microwave) range has an important element in its design, without which no measurement is possible, namely, a vector voltmeter that measures the phase shift and the ratio of signal amplitudes. Practically no one is engaged in the implementation of such devices and such developments are mainly the intellectual property of large companies, therefore, the design and creation of such a device in a widely available version is necessary. We have considered modern modulation formats and the implementation of transponders for the transmission of optical signals using multi-level formats of quadrature phase shift manipulation with double polarization (DP QPSK) and 16-position quadrature amplitude modulation with double polarization (DP 16QAM), as well as the basic methods for constructing vector voltmeters using microcontrollers and field programmable gate arrays (FPGA), optical communication channels were simulated and a phase shift measurement device was created. As a result of our research, we obtained a vector voltmeter on an FPGA, which, in turn, can be used to create an installation for measuring the phase shift of mixers connected via an Ethernet interface. Also, in the Verilog HDL hardware programming language for the Altera Cyclone V FPGA, a program code has been compiled for an electronic computing machine to measure the phase difference of two harmonic signals. A C program has been implemented for the ARM Cortex A9 processor in the Quartus Prime Lite environment as part of the Cyclone V ultra-large integrated circuit (VLSI), transmitting measurement results in real time over the 1GB interface to a computer with the ability to receive control commands.