Abstract: The generator of the invention includes an initialization circuit (CI) delivering four initialization words (QI, RI, SI, TI), one calculation circuit (CC) composed of four sub-units (SQ, SR, SS, ST) corresponding to four generating polynomials of orders 5, 5, 7 and 7, and finally one output logic circuit (CS) delivering a pseudo-random byte sequence.Application for systems with access control, especially television systems.

Abstract: A demodulator including a Hilbert transformer (20), a carrier regenerating circuit (30), a first delay line (35), a second delay line (36), a first switching device (38), a second switching device (39), a first multiplier (40), a second multiplier (42), a second adder (44), a third switching device (46), a third multiplier (48), a fourth switching device (50), a fourth multiplier (52), a second adder (54) and a divider circuit (60). This demodulator is able to demodulate either a frequency modulated signal, or a signal with double amplitude modulation in quadrature and with suppressed carrier.

Abstract: A sound pick-up and reproducing system, comprising a first and a second pair of directional microphones respectively disposed at a first and a second given distance from the sonic scene to be transmitted, said second distance being greater than said first distance, said four microphones being closely coupled; the system is characterized in that the spacing between the microphones of the second pair is substantially less than that between the microphones of the first pair, and in that the angular divergence between the sound pick-up axes of the second pair is substantially less than the angular divergence between the sound pick-up axes of the first pair of microphones.