Abstract:
Method of high-resolution direction finding to an arbitrary even order, 2q (q>2), for an array comprising N narrowband antennas each receiving the contribution from P sources characterized in that the algebraic properties of a matrix of cumulants of order 2q, C2q,x(l), whose coefficients are the circular cumulants of order 2q, Cum[xi1(t), . . . , xig(t), xiq+1(t)*, . . . , xi2q(t)*], of the observations received on each antenna, for cumulant rankings indexed by l, are utilized to define a signal subspace and a noise subspace.
Abstract:
A method for the blind identification of sources within a system having P sources and N receivers comprises at least one step for the identification of the matrix of the direction vectors of the sources from the information proper to the direction vectors ap of the sources contained redundantly in the m=2q order circular statistics of the vector of the observations received by the N receivers. Application to a communications network.
Abstract:
An antenna processing method for centered or potentially non-centered cyclostationary signals, comprises at least one step in which one or more nth order estimators are obtained from r-order statistics, with r=1 to n−1, and for one or more values of r, it comprises a step for the correction of the estimator by means of r-order detected cyclic frequencies. The method can be applied to the separation of the emitter sources of the signals received by using the estimator or estimators.
Abstract:
Method of high-resolution direction finding to an arbitrary even order, 2q (q>2), for an array comprising N narrowband antennas each receiving the contribution from P sources characterized in that the algebraic properties of a matrix of cumulants of order 2q, C2q,x(l), whose coefficients are the circular cumulants of order 2q, Cum[xi1(t), . . . , xiq(t), xiq+1(t)*, . . . , xi2q(t)*], of the observations received on each antenna, for cumulant rankings indexed by l, are utilized to define a signal subspace and a noise subspace.
Abstract:
A method for the fourth-order, blind identification of at least two sources in a system comprising a number of sources P and a number N or reception sensors receiving the observations, said sources having different tri-spectra. The method comprises at least the following steps: a step for the fourth-order whitening of the observations received on the reception sensors in order to orthonormalize the direction vectors of the sources in the matrices of quadricovariance of the observations used; a step for the joint diagonalizing of several whitened matrices of quadricovariance in order to identify the spatial signatures of the sources. Application to a communication network.FIG. 3 to be published.
Abstract:
A method forms a bipolar transistor in a semiconductor substrate of a first conductivity type. The method includes: forming on the substrate a single-crystal silicon-germanium layer; forming a heavily-doped single-crystal silicon layer of a second conductivity type; forming a silicon oxide layer; opening a window in the silicon oxide and silicon layers; forming on the walls of the window a silicon nitride spacer; removing the silicon-germanium layer from the bottom of the window; forming in the cavity resulting from the previous removal a heavily-doped single-crystal semiconductor layer of the second conductivity type; and forming in said window the emitter of the transistor.
Abstract:
A bipolar transistor with very high dynamic performance, usable in an integrated circuit. The bipolar transistor has a single-crystal silicon emitter region with a thickness smaller than 50 nm. The base of the bipolar transistor is made of an SiGe alloy.
Abstract:
A method of synchronizing a substantially rectilinear signal being propagated through an unknown channel, in the presence of unknown substantially rectilinear interferences, received by an array of N sensors, in which a known training sequence s(nT) is used comprising K symbols and sampled at the symbol rate T (s(nT), 0≦n≦{tilde over (K)}1), characterized in that, based on observations x((n+l/p)T) over the duration of the training sequence, where p=T/Te is an integer and Te the sampling period, a virtual observation vector X((n+l/p)T)=[x((n+l/p)T)T, x((n+l/p)T)†]T is defined, as well as a decision criterion or decision statistic taking into account the second-order non-circular nature of the interferences, by using the first and second correlation matrices of the virtual observation vector X((n+l/p)T).
Abstract:
A method for the verification of anti-jamming in a communications system comprises several sensors or adaptive antennas, comprising at least the following steps: estimating the mean power π;^y of the output of the communications system, estimating the respective power values Pu or P′u, of a station u, the antenna noise Pa or P′a, the thermal noise PT, or P′T, estimating at least one of the following ratios: J tot / S tot = ( ∑ p = 1 P P p ) / ( ∑ u = 1 U P u ) J tot / S u = ( ∑ p = 1 P P p ) / P u J u / S u = ( ∑ p = 1 P P pu ) / P u comparing at least one of the three ratios with a threshold value.
Abstract:
A novel bipolar transistor with very high dynamic performances, usable in an integrated circuit. This bipolar transistor comprises a single-crystal silicon emitter region with a thickness smaller than 50 nm. The base of the bipolar transistor is made of an SiGe alloy.