An Analysis of an RF Link Budget and RSSI Circuit Design for Long-Range Communications

It is important for vehicle drivers to obtain useful information through systems such as a global positioning system (GPS), an intelligent transportation system (ITS), or WiFi data communication. Communication over long distances can be beneficial in many ways. In this paper, an RF link budget calculation for a long range WiFi communication service based on multi-hop communication was introduced, and breakpoint distance and Fresnel zone were calculated to determine the appropriate height of antennas of WiFi repeaters. In addition, this paper demonstrates a received signal strength indicator (RSSI) circuit employed to find the strongest received signal from multiple directions.