摘要:
The method of improving the carrier-to-noise ratio for a receiver with diversity, and the associated device, consists, after extracting, by phase shifting, the noise component of the signals to be demodulated, in optimizing the cancellation of the useful component via a feedback loop acting on the phase shifter and in summing the noise component in phase and in phase opposition with these signals to improve the carrier-to-noise ratio.
摘要:
This invention concerns a repeater for radio frequency signals having a channel filter and an active filter connected to the channel filter output. The active filter covers the channels adjacent to the channel filter and includes an amplifier and; two bandpass filters in parallel connected as a negative feedback loop around the amplifier. The first bandpass filter covers the lower adjacent channels and the second bandpass filter covers the higher adjacent channels. The invention notably applies to the development of domestic repeaters for mobile terminals meeting the DVB-H digital television standard.
摘要:
The invention relates to a switch with selective isolation and also to a switching device with selective isolation for multimedia terminals. The switch formed by 2 transistors (T1, T2) is feedback controlled by a feedback control signal V tune at a pre-defined frequency thus guaranteeing the selective isolation at this frequency. The switching device for switching the transmission/receiver channels of a multimedia terminal is formed by selective isolation switches that can be integrated using MMIC technology.
摘要:
The method of improving the carrier-to-noise ratio for a receiver with diversity, and the associated device, consists, after extracting, by phase shifting, the noise component of the signals to be demodulated, in optimizing the cancellation of the useful component via a feedback loop acting on the phase shifter and in summing the noise component in phase and in phase opposition with these signals to improve the carrier-to-noise ratio.
摘要:
The invention proposes a filtering device having a frequency response which is symmetrical, using asymmetrical filters coupled by transposition means. The advantageous characteristics of the asymmetrical filters are retained and the faults associated with the asymmetry are eliminated. The asymmetrical filters are, for example, quartz filters. The invention also proposes an external transmission and reception unit, using the filtering device with the application of the filtering method.
摘要:
The invention relates to a method of resending at least one digital signal, comprising a step of reception by cable of the signal comprising signaling information, a step of resending of this signal at a resend frequency by an antenna, and also comprising a step of selecting the resend frequency as a function of the signaling information; a step of transposing the signal into the selected frequency of the resend signal and a step of monitoring and adjusting the frequency of the resend signal as a function of the selected frequency of the resend signal.
摘要:
The invention relates to a device for receiving signals in a MIMO system comprising: m signal receiver channels, where m is greater than 1; an antenna system constituted either by n directive antennae n>m, each antenna being able to receive signals in one of its own angular sectors, the angular sectors of the n antennae essentially not overlapping each other and together thrilling a total angular sector of 360 degrees, or a multi-sector antenna with n angular sectors n>m the n angular sectors essentially not overlapping each other and having a distinct access; and switching means to associate with each signal receiver channel an antenna from among the n antennae according to a switching schema selected by control means, the switching schema being selected from a plurality of switching schemas of a switching matrix according to a criterion representing the quality of the reception of the signals by said signal receiver channels.
摘要:
The invention proposes a filtering device having a frequency response which is symmetrical, using asymmetrical filters coupled by transposition means. The advantageous characteristics of the asymmetrical filters are retained and the faults associated with the asymmetry are eliminated. The asymmetrical filters are, for example, quartz filters. The invention also proposes an external transmission and reception unit, using the filtering device with the application of the filtering method.
摘要:
The invention relates to VHF adapters for cable networks of the ODU type. It consists in using two conversion chains, up and down, in which a very stable signal reference oscillator drives means of generating the VHF and IF local frequencies common to these two conversion chains. A very selective surface wave filter makes it possible to rject the frequency of the local oscillator at the level of the first intermediate frequency. It makes it possible to obtain a DOCSIS compatible millimeter MWS ODU whose frequency stability and spectral purity satisfy the constraints of the cable standard without undertaking spectral inversion of the signals transmitted and received.
摘要:
The invention relates to a dielectric resonator oscillator, comprising a dielectric resonator contained in a resonant cavity in order to generate a signal oscillating at a predetermined central frequency, the dimensions of the resonator and the limiting conditions in the cavity being capable of determining the resonant frequency of the resonator. It comprises means sensitive to acoustic pressure waves capable of modifying the distribution of the electromagnetic fields in the cavity as a function of said acoustic pressure waves. The invention also relates to a voice control device equipped with an oscillator according to the invention. Particular application to remote voice control devices for controlling domestic equipment.