By R.F. Kearns, V.S. Shukla, P.N. Baum, and L.W. Ulbricht, GTE Laboratories Incorporated
Use of microwave subcarrier multiplexing (SCM) for transmission and distribution of a large number of video channels over optical fiber offers an attractive alternative to existing coaxial and multifiber systems. This paper describes a SCM system carrying 80 FM video channels, achieving a 60 dB SNR and an optical power budget of 14 dB. A transmission distance of20 km with a 3 dB margin was also achieved without degradation. Such a system can be used in next-generation CA1V super-trunk-type applications. Superior performance in terms of SNR and optical power was achieved by implementing the system based on optimization and judicious choice of parameters affecting its performance. The frequency plan, based on 9 MHz frequency deviation, uses the 3-6 GHz frequency band. The system uses high-frequency lasers having a 10 GHz bandwidth and RlN below -140 dB /Hz.