A television signal transmission system is used for transmitting an N-level video related data signal. The data signal is processed prior to transmission such that the majority of N-level symbols comprise a non-negative level for facilitating receiver lock-up. An in-phase pilot component may be added...http://www.google.com/patents/US5181112?utm_source=gb-gplus-sharePatent US5181112 - Television signal transmission system with carrier offset compensation
