Pcm transmission system utilizing analog phase discriminator for binary code signals

Claim 1

In a PCM transmission system for transmitting binary code signals, a transmitter comprising a pulse source of binary code signals for providing binary pulses, wave shaper means having an output and an input connected to said pulse source for shaping said binary pulses into a rectangular wave pulse train having spaced positive pulses each having a pulse duration equal to the period from the leading edge of a corresponding one of said binary pulses coincident with the leading edge of said corresponding positive pulse to the leading edge of the next succeeding one of said binary pulses, said wave shaper means comprising a first wave shaper having an output and an input for shaping positive ternary pulses into a first rectangular wave pulse train having spaced positive pulses each having a pulse duration equal to the period from the leading edge of a corresponding one of said positive ternary pulses coincident with the leading edge of said corresponding positive pulse to the leading edge of the next succeeding one of said positive ternary pulses and a second wave shaper having an output and an input for shaping negative ternary pulses into a second rectangular wave pulse train having spaced positive pulses each having a pulse duration equal to the period from the leading edge of a corresponding one of said negative ternary pulses coincident with the leading edge of said corresponding negative pulse to the leading edge of the next succeeding one of said negative ternary pulses, positive pulse deriving means connected between said pulse source and the input of said first wave shaper for supplying positive ternary pulses to said first wave shaper and negative pulse deriving means connected between said pulse source and the input of said second wave shaper for supplying negative ternary pulses to said second wave shaper, a carrier source of carrier wave, phase modulator means having an output, an input connected to the output of the first wave shaper of said wave shaper means and an input connected to said carrier source for phase modulating said carrier wave with said rectangular wave pulse train to provide a phase shifted carrier at its output, and transmitting means connected to the output of said phase modulator means for transmitting said phase shifted carrier via wireless, said transmitting means including a band-pass filter connected to the output of said phase modulator means for filtering the phase shifted carrier and having a bandwidth of + OR - 21, where 1 2 pi /2T and T is the period of said binary pulses, antenna means and frequency step up means connected between said band-pass filter and said antenna means for increasing the frequency of the phase shifted carrier; and a receiver comprising receiving means for receiving the transmitted phase shifted carrier, analog phase discriminating means having an output and an input connected to said receiving means for demodulating the received phase shifted carrier to the binary pulses provided by the pulse source of said transmitter, said receiving means comprising antenna means and frequency step down means connected between said antenna means and the input of said phase discriminating means for decreasing the frequency of the received phase shifted carrier, and an output connected to the output of said phase discriminating means for deriving said binary pulses from said receiver.