A bi-directional multimedia satellite communication system has been proposed to offer high-speed Internet access links. For efficient use of frequency bandwidth and transponder power, this system employs super-posed transmission scheme, which Spread Spectrum (SS) signals are superposed on the high-speed TDM signal. In order to realize this scheme, two novel technologies are introduced. They are the adaptive interference cancellation technique, and the burst mode SS demodulation technique. This paper describes the results of a system performance evaluation that uses prototypes. The measured results demonstrate that the adaptive interference canceler can eliminate interference in spite of amplitude fluctuation, and also demonstrate that the burst-mode SS demodulator can demodulate without degradation, even if there is carrier frequency error.