Abstract: In a signal transmission system for broadband signals wherein the transmitting transducer and/or the receiving transducer has a non-isotropic radiation characteristic, properties of the received broadband signal, for example waveform shape, spectrum, duration and probability density function, depend on the alignment orientation of the transducers. A discriminator circuit is provided in the receiver for identifying or estimating parameters related to one or more of such properties as a measure of alignment orientation of the transducers. The invention can be utilized, for example, in noise-suppressing radio frequency message transmission systems wherein band spreading modulation (spread-spectrum-system) results in transmission of a much greater bandwidth than a conventional transmission of the message baseband frequencies.

Abstract: A receiving circuit for an interference-suppressing communications system having a narrow-band conventional message modulation and additional pseudo-noise phase shift keying (PN-PSK), has a pseudo-random generator whose pseudo-random sequence is identical to the pseudo-random sequence provided by the system transmitter. The pseudo-random generator actuates a phase-shift keying element to cancel the phase shift modulation produced at the transmitter. A matched filter or correlation network for correlation of the pseudo-random sequence at the receiver with the pseudo-random sequence contained in the received signal is provided. The message modulation impairs the function of the matched filter or the correlation network. The degrading influence of message modulation is to be eliminated, at least, reduced.