Shared use of a satellite transponder by analog and digital carriers

This paper examines the effects of interference between an analog television carrier and a digital carrier, or multiple digital carriers, coexisting in a single satellite transponder. As the satellite distribution of video and audio signals progresses toward the use of digital transmission, it is becoming more and more common to find an analog television carrier sharing a transponder with a digital television carrier. In some cases, multiple digital carriers share a single transponder with an analog television carrier. The results of laboratory measurements and over-the-air tests are presented. The practical aspects of analog and digital carrier coexistence, including required power backoff values and resulting receive antenna sizes, are discussed