RSU phased array transmitting system based on direct frequency conversion

Abstract

The invention provides an RSU phased array transmitting system based on direct frequency conversion. The system comprises an RSU processor module, an FPGA digital vector baseband signal generation and beam scanning algorithm module, a DAC module, a CLK module, an LPF module, an orthogonal direct frequency conversion module, an LO local oscillator module, a PA module and an antenna array module. The FPGA digital vector baseband signal generation and beam scanning algorithm module obtains data frame information needing to be sent by the RSU processor module, and the FPGA digital vector baseband signal generation and beam scanning algorithm module, the DAC module, the LPF module, the orthogonal direct frequency conversion module, the PA module and the antenna array module are connected in sequence. According to the RSU phased array transmitting system based on direct frequency conversion, stepless adjustment of the phase and the amplitude can be achieved so that transmitting beams are accurately controlled, ETC adjacent channel interference and car following interference are reduced, and the material cost of the RSU is decreased.

Description

technical field [0001] The invention relates to a phased array transmitting system, in particular to a phased array transmitting system based on a direct frequency conversion RSU. Background technique [0002] ETC: (Electronic Toll Collection) non-stop toll collection system is the most advanced road and bridge toll collection method in the world at present, through the special microwave short-range between the vehicle electronic tag installed on the vehicle windshield and the microwave antenna on the ETC lane of the toll station Communication, deducting the amount on the user card or using computer networking technology to carry out background settlement processing with the bank, so as to achieve the purpose of paying road and bridge tolls without stopping when vehicles pass through road and bridge toll stations. ETC is an advanced electronic toll collection technology. At the ramp entrance and exit and the main line sign station, both are ETC application models in the clos...

AI Technical Summary

Problems solved by technology

[0005] With the application and promotion of ETC, there are more and more ETC parallel lanes, and the problems of ETC adjacent lane interference and car-following interference have been prominent, which have been plagued by the development of ETC. The phased array transmit beam scanning technology, the phased array transmit beam scan is realized by controlling the phase and amplitude of the multi-channel 5.8G frequency band RF signal, the phase is controlled by a phase shifter, and the amplitude is controlled by an attenuator; however, The 5.8G frequency band phase shifter and attenuator are very expensive, and each channel needs to be used, which greatly increases the material cost of the RSU

[0006] In addition, phase shifters and attenuators use limited steps (usually less than or equal to 64 levels) to phase shift and attenuate signals, and cannot achieve stepless phase shift and stepless amplitude modulation, so it is difficult to precisely adjust the beam. In order to solve the above technical problems, this application provides a phased array transmitting system based on direct conversion RSU

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