Technical aspects of a IVHS DGPS broadcast service using RBDS

GPS has become the primary choice in Intelligent Vehicle Highway Systems (IVHS) for vehicle location monitoring. The use of GPS technology in the autonomous mode is not accurate enough in urban environments where there are complicated freeway systems, dense city street layouts and other urban roadways which make accurate vehicle location monitoring difficult. The major problem in vehicle location monitoring has been providing some form of efficient DGPS correction broadcast. Cost effective solution to providing DGPS corrections for IVHS is using the new broadcast data standard, radio broadcast data standard (RBDS). The standard defines the broadcast format for transmitting data over existing FM radio station subcarriers. This paper reviews the FM multiplex signal spectrum, the RBDS standard, the technical RBDS signal broadcast spectrum and the RBDS data groups. It also discusses the proposed standard for the broadcast of DGPS corrections using RBDS as currently defined by the DGPS working group