Abstract: To transmit digital data in a color television signal, a color burst is transmitted in its standard reference position to represent a first logic state, e.g., a "0" and is shifted by a limited amount from the standard reference position to represent a second logic state, e.g., a "1". More specifically, the "bits" of the data are "read-out" of a register in response to the horizontal synchronization pulses generated in the transmitter and are used as control signals to generate burst flag pulses in the standard or a shifted position depending on whether the bit to be transmitted is a logic "0" or a logic "1". The burst flag pulses are used to insert the color bursts in the back porch portion of the horizontal blanking interval. At the receiver, a burst demodulator extracts the color bursts and determines the position of each color burst to recover the transmitted data.

Abstract: A bit-decision circuit or slicer for a digital communications receiver includes a first comparator which compares the received signal level with a reference slicing level. In order to have the lowest error rate, the reference slicing level must be controlled. Control is provided by periodic level indicating pulses in the transmitted signal. The level indicating pulses have predetermined nominal duration and controlled rise and fall times. A pulse width locked loop at the receiver responds to the level indicating pulse at the output of the comparator. The pulse width locked loop includes a start-stop oscillator which produces an odd or an even number of oscillations in response to each level-indicating pulse depending upon the ON time of the oscillator.

Abstract: A clock pulse regenerator uses a pair of oscillators each comprising a NOR gate and a transmission line feedback element. The oscillators are provided with complementary data pulses and provide an output signal only when the data signal is of a selected logic level. The output signals are combined to form a continuous regenerated clock signal. An FSK encoder using similar oscillators is also disclosed.