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The paper represents some engineering solutions which provide coherence and coherent data transmission in radar and communication systems with phased array with computing components designed on the principles of FPGA-based reconfigurable computer systems. We developed the coherent gathering methods of digitized data from the phased array antenna elements, and data transmission among the distributed components that perform coherent digital signal processing. To provide coherent data processing and transmission, we use the signal of clock reference signal and the CPU-time, centrally generated and transmitted into all nodes with the same delay. Generation of all control signals in the processing nodes are based on these two signals. For data transmission, we suggest to use high-speed optical links, which are the most reliable in environmental conditions. To transmit the digitized data from phased array antenna elements, we suggested using packet data transmission with data integrity control and time-linked digitized data. Also, we applied a mechanism to monitor the delay mismatch of packets transmitted via different links and to synchronize them in data receivers. The most probable emergency situations for the data transmission system are considered and methods of parrying and minimizing the impact of transmission errors on the formation of the result are proposed. The developed engineering solutions were tested on a real FPGA-based beam-forming device with simulation of emergency situations. Many hours of tests and runs showed that all emergency situations were successfully solved by the data communication system. |
