摘要 |
A method and apparatus for discriminating the data signal of a transmitter means. Binary encoded data is transmitted between a transmitter means and a receiver means in an amplitude modulated signal varying about a threshold level. A means and method are included for determining the number of threshold crossings of the carrier during each of a number of discrete successive time intervals. A further method and means characterizes those of said time intervals wherein the number of threshold crossings equals or exceeds a first predetermined number as a mark, and those of said time intervals wherein the number of threshold crossings does not exceed said predetermined number as a null. The number of successive marks not separated by a predetermined number of nulls is then counted by a further aspect of the method and means. A series of successive marks in excess of a second predetermined number is then characterized as a one, and a series of successive marks in a range below said second predetermined number is characterized as a zero. The signal transmitted by said transmitter means is discriminated from interference by spurious signals.
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