Abstract: Within the differential detection demodulator, the received signal is first quantized by a limiter amplifier and then subjected to frequency conversion by a frequency converter including: an exclusive OR element; a running average generator consisting of a shift register and an adder; and a comparator. In response to the output of the frequency converter, the phase comparator outputs a relative phase signal representing the phase shift of the received signal after frequency conversion relative to the phase signal representing the phase shift of the received signal after frequency conversion relative to the phase reference signal. The phase comparator includes: an exclusive OR element; an absolute phase shift measurement means consisting of an adder and D flip-flop arrays and; and a D flip-flop serving as a phase shift polarity decision means.

Abstract: Within the differential detection demodulator, the received signal is first quantized by a limiter amplifier 10 and then subjected to frequency conversion by a frequency converter 50 including: an exclusive OR element 51; a running average generator 52 consisting of a shift register 53 and an adder 54; and a comparator 55. In response to the output of the frequency converter 50, the phase comparator 60 outputs a relative phase signal representing the phase shift of the received signal after frequency conversion relative to a phase reference signal. The phase comparator 60 includes: an exclusive OR element 61; an absolute phase shift measurement circuit 62 consisting of an adder 63 and D flip-flop arrays 64 and 65; and a D flip-flop 66 serving as a phase shift polarity decision circuit.

Abstract: Within the differential detection demodulator, the received signal is first quantized by a limiter amplifier 10 and then subjected to frequency conversion by a frequency converter 50 including: an exclusive OR element 51; a running average generator 52 consisting of a shift register 53 and an adder 54; and a comparator 55. In response to the output of the frequency converter 50, the phase comparator 60 outputs a relative phase signal representing the phase shift of the received signal after frequency conversion relative to the phase reference signal. The phase comparator 60 includes: an exclusive OR element 61; an absolute phase shift measurement means 62 consisting of an adder 63 and D flip-flop arrays 64 and 65; and a D flip-flop 66 serving as a phase shift polarity decision means.

Abstract: A spread spectrum demodulator for use with a phase-shift-keying modulated spread spectrum signal used in mobile satellite communications. An objective of the spread spectrum demodulator is to perform tracking by producing from a correlation pulse signal an error signal having a time discrimination characteristic. The spread spectrum demodulator generates from the correlation pulse signal an error signal whose level varies in response to a phase difference between a pseudonoise signal contained in a received signal and a reference pseudonoise signal. A clock in synchronism with the received signal is generated from this error signal, thereby demodulating the received signal.

Abstract: An additive to cement comprises a granular zinc salt of a copolymer of an olefin having 2 to 8 carbon atoms and an ethylenically unsaturated dicarboxylic anhydride, prepared by reacting the powder of the copolymer with powder of zinc oxide or zinc hydroxide in the presence of water.

Abstract: In the concatenated coding data compensation communication system, the coding and decoding are performed in a differential coder and a differential decoder. 2-channel output obtained after coding is parallel-to-serial converted and then subjected to synonym insertion before being transmitted. On the receiving side, the received data is supplied after detection and removal of sync-words in a Viterbi decoder, and the decoder is operated on the basis of the timing of detection of the detected sync-words.