Abstract: A device for receiving a broadband multi-channel radiofrequency signal includes a radiofrequency analog input stage connected to an intermediate-frequency conversion stage. The conversion stage includes at least one conversion chain having a frequency mixer that transposes the signal to an intermediate frequency connected to the input of an analog-digital converter with a high frequency sampling rate. The intermediate and sampling frequencies in each conversion chain are selected such that, considering the noise generated by the sampling overtones of the corresponding analog-digital converter, each of the radiofrequency signal channels has a signal/noise ratio that is greater at output than a predetermined value of at least one conversion chain.

Abstract: There is disclosed a method of inserting a secondary stream of binary information into a main symbol stream of at least one standard digital modulation. The stream to be transmitted resulting from the insertion of the secondary stream in the main stream is a symbol stream of a modified digital modulation. The stream to be transmitted has the same symbol rate as the main stream. The sequence of symbols of the stream to be transmitted is encoded according, cumulatively, to a first condition over at least two consecutive symbols of the main stream, on the one hand; and to a second condition on a current bit or a plurality of current bits of the secondary stream, on the other hand.

Abstract: A device for receiving a broadband multi-channel radiofrequency signal includes a radiofrequency analog input stage connected to an intermediate-frequency conversion stage. The conversion stage includes at least one conversion chain having a frequency mixer that transposes the signal to an intermediate frequency connected to the input of an analog-digital converter with a high frequency sampling rate. The intermediate and sampling frequencies in each conversion chain are selected such that, considering the noise generated by the sampling overtones of the corresponding analog-digital converter, each of the radiofrequency signal channels has a signal/noise ratio that is greater at output than a predetermined value of at least one conversion chain.

Abstract: A device for receiving a broadband multi-channel radiofrequency signal includes a radiofrequency analog input stage connected to an intermediate-frequency conversion stage. The conversion stage includes at least one conversion chain having a frequency mixer that transposes the signal to an intermediate frequency connected to the input of an analog-digital converter with a high frequency sampling rate. The intermediate and sampling frequencies in each conversion chain are selected such that, considering the noise generated by the sampling overtones of the corresponding analog-digital converter, each of the radiofrequency signal channels has a signal/noise ratio that is greater at output than a predetermined value of at least one conversion chain.

Abstract: The invention relates to a device for receiving a broadband multi-channel radiofrequency signal, consisting of a radiofrequency analog input stage (3) connected to an intermediate-frequency conversion stage (?), said conversion stage comprising at least one conversion chain (13, 15) comprising a frequency mixer (17, 19) that transposes the signal to an intermediate frequency connected to the input of an analog-digital converter (29, 31) with a high frequency sampling rate, characterized in that the intermediate and sampling frequencies in each conversion chain are selected such that, considering the noise generated by the sampling overtones of the corresponding analog-digital converter, each of the radiofrequency signal channels has a signal/noise ratio that is greater at output than a predetermined value of at least one conversion chain.

Abstract: There is disclosed a method of inserting a secondary stream of binary information into a main symbol stream of at least one standard digital modulation. The stream to be transmitted resulting from the insertion of the secondary stream in the main stream is a symbol stream of a modified digital modulation. The stream to be transmitted has the same symbol rate as the main stream. The sequence of symbols of the stream to be transmitted is encoded according, cumulatively, to a first condition over at least two consecutive symbols of the main stream, on the one hand; and to a second condition on a current bit or a plurality of current bits of the secondary stream, on the other hand.