Abstract: A pulse code generator generates a number of different pulse sequences within a given frame by comparing the state of a clock driven counter having the same length as the frame and the contents of a fixed memory which contains in sequential locations numbers corresponding to the time position of the pulses within the frame. The memory is addressed by a second counter, which is presettable and is driven by the output pulses from a comparator. By presetting the second counter the position of the first pulse in any sequence is generated.

Abstract: A pulse pattern detector includes a local pulse pattern generator starting in response to an incoming signal impulse whether or not it is included in the pulse pattern to be detected. There is a number of timing circuits for measuring the time lapsed from each of the pulses in the locally generated pulse pattern and memory means for storing the measured value of all but the last timing circuit as soon as a signal impulse is received. Comparators are provided to compare the contents of the memory means to find if all the memory circuits have recordings equal to a state of the timing circuit in which case a signal is generated indicating that the desired pulse pattern is detected in the incoming pulse sequence.