Design and selection of a ghost cancelling reference signal for television systems in North America

The necessity for a ghost cancelling reference (GCR) signal is introduced. Efforts by the Broadcast Technology Association (BTA) of Japan dating back to the early 1980s to design a GCR signal are described. Important design requirements of GCR signals are identified. The design of GCR signals, started in 1989, by North American Philips, David Sarnoff Research Centre, Samsung Electronics, AT&T and Zenith are described and discussed along with the final proposal by BTA. Some of the differences and comparisons provided in the final report are summarized. The North American Philips GCR signal was finally chosen as the standard for North America in the spring of 1992. The reasons for this decision are discussed. Several possibilities such as polyphase pseudo-noise sequences are discussed and their shortcomings are pointed out. A brief discussion of training signals (or GCR signals) for HDTV is presented.<
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