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.
Abstract:
Process for estimating the correlation matrix of signals of unknown characteristics in an array of N sensor. The process determines the correlation matrix {circumflex over (R)}s of the signals of known characteristics, estimates the correlation matrix {circumflex over (R)}x of the sensor signals, forms a matrix A equal to A={circumflex over (R)}s−1/2{circumflex over (R)}x {circumflex over (R)}s−1/2 and decomposes the matrix A into eigenelements, constructs a matrix B based on the eigenelements of the matrix A, and determines the estimated correlation matrix {circumflex over (R)}b of the interfering signals based on the estimated matrix {circumflex over (R)}s and of the matrix B, such that {circumflex over (R)}b={circumflex over (R)}s1/2 B {circumflex over (R)}s1/2. Such a process may find application to antenna processing.
Abstract:
The method consists in estimating the matrix of correlation R.sub.XX of the signals received on a set of N reception sensors, computing the reverse correlation matrix R.sub.XX.sup.-n, computing vectors of intercorrelation r.sub.Xd between the signals received on the set of the N sensors and a known replica signal d(k), computing a criterion of synchronization in calculating the products of the conjugate, transposed intercorrection vectors R.sub.XX.sup.-n and of the matrix of the intercorrelation vector r.sub.Xdi and comparing the value of the criterion obtained with a determined threshold value 1 to place the synchronization on the sample for which the value of the criteria exceeds the threshold value .eta.. To estimate the Doppler shift the synchronization sequence is subdivided into a determined number of sections of symbols to carry out fast Fourier transform computations on determined intercorrelation vectors in each section.
Abstract translation:该方法在于估计在一组N个接收传感器上接收到的信号的相关值E,cir R + EE XX矩阵,计算反向相关矩阵+ E,cir R + EE XX-n,互相关的计算向量+ E,cir r + EE Xd在所述N个传感器的组合上接收的信号和已知复制信号d(k)之间,计算共轭的乘积的计算准则,转置的互补向量+ E,cir R + EE XX-n和互相关向量rXdi的矩阵,并且将获得的准则的值与确定的阈值1进行比较,以将该准则置于样本上,其中标准值超过阈值eta。 为了估计多普勒频移,同步序列被细分为确定数量的符号段,以便在每个部分中确定的相互相关矢量上执行快速傅里叶变换计算。
Abstract:
Method and system for separating a plurality of users in a communication system including two transmitter antennas and N receiver antennas, said signals transmitted by said users containing symbols an, x( ) corresponding to the vector of the envelopes of the output signals of the 1 to N receiver antennas after a shaping filtering operation, characterized in that it uses a linear mean square filter extended over an observation vector {tilde over (x)}=[x(2n−1)T x(2n)T x(2n−1)H x(2n)H]T where x(2n−1) and x(2n) correspond to the (N×1) (N≧1) observations at the symbol times 2n−1 and 2n.
Abstract:
Method for measuring certain parameters of the impulse response of a propagation channel involving emitters and reflectors that are fixed or mobile, so as to detect and determine the parameters regarding the position and kinematics of these emitters and reflectors, or to auto-locate the reception system implementing the invention, in a system comprising N sensors receiving signals from said emitters or from the reflection on said reflectors, and comprising at least the following steps: determination of an ambiguity function which couples the spatial analysis and the delay-distance/Doppler-kinematic analysis, determination of at least one sufficient statistic C(l, m, K) corresponding to the correlation between the known signal s(kTe) corresponding to the complex envelope of the signal emitted and the output of a filter w(l,m) where l corresponds to a temporal assumption (delay-distance, temporal ramp, etc.) and m to a frequency assumption (Dopper-kinematic, Doppler ramp, etc.), determine the values of the pair (l, m) by comparing the value of the statistic for the pair (l, m) with a threshold value.
Abstract:
A bipolar transistor having a base region resting by its lower surface on a collector region and surrounded with a first insulating layer, a base contact conductive region in contact with an external upper peripheral region of the base region, a second insulating region in contact with an intermediary upper peripheral region of the base region, an emitter region in contact with the central portion of the base region. The level of the central portion is higher than the level of the intermediary portion.
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 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;ˆy 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 process and device related to multisensor radio direction finding receivers usable in radio communication systems including several emission sources. The process and device isolate the contribution of each emission source in sensor signals so as to perform direction finding on a single emission source only, based on learning sequences inserted into waveforms emitted by each of the emission sources. Such a process and device may find particular application to cellular communication networks.
Abstract:
A method for measuring certain parameters of the impulse response of a propagation channel involving emitters and reflectors that are fixed or mobile, and for detecting and determining the parameters regarding the position and kinematics of the emitters and reflectors, or for auto-locating the reception system implementing the invention, in a system comprising N sensors receiving signals from the emitters or from the reflection on the reflectors. The method determines an ambiguity function which couples the spatial analysis and the delay-distance/Doppler-kinematic analysis, and determines at least one sufficient statistic Ĉ(l,m,K) corresponding to the correlation between the known signal s(kTe) corresponding to the complex envelope of the signal emitted and the output of a filter w(l,m) where l corresponds to a temporal assumption and m corresponds to a frequency assumption. The method also determines the values of the pair (l,m) by comparing the value of the statistic for the pair (l,m) with a threshold value.