Abstract:
Blind or partially blind process to determine characteristic space-time parameters of a propagation channel in a system comprising at least one reception sensor receiving a signal y(t). It comprises at least one step in which the specular type structure of the channel is used and a step for the joint determination of parameters such as antenna vectors (a) and/or time vectors (τ) starting from second order statistics of the received signals.Application for monitoring the spectrum of a propagation channel for positioning purposes starting from one or several HF stations or for standard communication links with equalization or positioning or spatial filtering.
Abstract:
A method and device to estimate the impulse response h of a propagation channel in a system comprising at least one or more sensors, comprising at least one step for estimating the statistics of the additive noise resulting from the interference and from the thermal noise on the basis of the statistics of the received signal
Abstract:
A method for forming a heterojunction bipolar transistor including the steps of: forming in a semiconductor substrate a collector area of a first doping type; growing by epitaxy above a portion of the collector area a silicon/germanium layer of a second doping type forming a base area; forming above the silicon/germanium layer a sacrificial emitter formed of a material selectively etchable with respect to the silicon/germanium layer and with respect to the layers and consecutively-formed insulating spacers; forming first insulating spacers on the sides of the sacrificial emitter; growing by epitaxy a silicon layer above the exposed portions of the silicon/germanium layer; forming second insulating spacers adjacent to the first spacers and laid on the silicon layer; covering the entire structure with an insulating layer; partially removing the insulating layer above the sacrificial emitter and removing the sacrificial emitter; filling the space previously taken up by the sacrificial emitter with a semiconductor material of the first doping type.
Abstract:
Disclosed is a method enabling the improvement of the multisensor reception of a system of radiocommunications exchanging signals between at least one fixed base station providing for multisensor reception by means of a network of sensors, and the processing of the signals. This method consists, in a transparent manner perceived from the base station, in computing a weighting vector W for the formation of channels at reception. The weighting vector W is estimated by an adaptive algorithm leading to a maximization of the signal-to-noise ratio. Application: mobile radiocommunications. FIG. 1