Performance improvement of transmission antenna installed on outside broadcasting van for live broadcast of road race

Outside broadcasting is the term used to describe the production of television or radio programmes away from a purpose-built studio and is typically used to broadcast live events such as sports, festivals and breaking news. During live outside broadcasting of road races, such as marathons and ekiden (Japanese term for long-distance relay running races), video images are taken using cameras on moving outside broadcasting (OB) vans and the signals of the video images are transmitted to the receiving stations. The multiple receiving points are set on the top of buildings, telegraph poles, and mountains along the marathon course and the signals are transmitted by OFDM transmission systems in the 700 MHz band (770-806 MHz) [1,2]. Most of the receiving points are located at the corners; therefore, the transmitted signal is received so as to be sandwiched between the front and back of OB van by the receiving antennas at those receiving points. The received signals at the receiving points are sent to a studio via radio-on-fiber links, and the signal with the best quality is used. We propose an array Arrangement and Location of Receiving Points in Kyoto antenna as a transmission antenna and evaluated its effectiveness for providing high gain toward the front and back of an OB van to achieve high reliability of the wireless links at the course in Kyoto.