By Yozo Utsumi, Hiroo Arata, and Mikio Maeda, Japan Broadcasting Corporation
We performed a MUSE (Multiple Sub-Nyquist Sampling Encoding) transmission experiment through two transmission systems in cascade, comprising a communications satellite and coaxial cable facilities, with the cooperation of NCTA and HBO in April 1989. At that time, the MUSE-FM signal was uplinked at the HBO Communications Center in Long Island, New York, to SATCOM Kl and downlinked to two cable headends in the Washington suburbs. At the cable headends, this signal was transformed into the MUSE-VSB•AM signal, and transmitted ·to remote subscriber locations. Typical results of this experiment were as follows: the unweighted SN ratio is greater than 39 dB and the picture quality is better than 4 on a 5-grade subjective evaluation.
We also developed a demand access optical fiber CATV system for HDTV MUSE signals. On a trunk line, 34 MUSE-FM signals can be transmitted over about 20 km, and at the hub, any 4 MUSE-FM signals can be selected by channel request signals from an individual subscriber, and are transmitted on each subscriber line of about 2 km. The CN ratio through this total system is greater than 17.5 dB, which is the perceptible noise limit of MUSE-FM transmission, whose bandwidth is 27 MHz.