Clock Recovery Scheme for Ternary Duobinary AM/PSK Signal
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
The "eye" diagram of the envelope-detected baseband signal in the receiver is shown in Fig. 1. Also, as shown in Fig. 1, it is to be noted that the optimum threshold voltage for the timing detector for the symbols "1" and "0" is not the same as that for the non-data symbols. Therefore, if only one detector is used to extract the timing information from the "1" and "0" symbols, then the non-data symbols will cause a large timing error, such as Te in Fig. 1. In certain proposed standards, the non-data symbols are used during pseudo-silence (idle) to mark starting and ending frame delimiters, and to indicate forced data transitions made to break up long sequences of identical data symbols.