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:
Method and system for locating one or more transmitters in the potential presence of obstacles in a network comprising a first receiving station A and a second receiving station B that is asynchronous with A. The method includes the identification of a reference transmitter through an estimation of its direction of arrival AOA-TDOA pair (θref, Δτref) on the basis of the knowledge of the positions of the reference transmitter and of stations A and B, an estimation of the direction of arrival of the transmitter or transmitters and of the reflectors (or estimation of the AOA) on station A, and the correction of the errors of asynchronism between station A and station B by using the reference transmitter and the location of the various transmitters on the basis of each pair (AOAi, TDOAi).
Abstract:
Disclosed is a method of blind demodulation of signals arising from one or more transmitters, the signals including a mixture of symbols comprising at least one step of separating the transmitters by using the temporal independence of the symbol trains specific to a transmitter and the mutual independence of the transmitters.
Abstract:
The invention concerns digital signal transmission. In particular, it concerns high speed transmission using layered space-time encoding architecture adapted to all types of propagation channels.The invention therefore proposes a digital signal transmission system comprising: a space-time encoder (1) receiving a flow of data to be transmitted d[i], formatting this data d[i] as symbol vectors v[k] of dimension P(P>1) and generating said symbol vectors v[k], and modulator-transmitters {2p}(1≦p≦P), each receiving one component of the symbol vector m[k] output from the space-time encoder (1), applying the constellation of a predetermined modulation to said symbol mp[k], and converting the symbol obtained ap[k] into a signal sp(t) presenting time diversity transmitted on said antenna (24p) connected to said transmitter (2p). To demodulate in parallel the Q signals of the space-time observation y _ [ k ] = ∑ j = 0 J - 1 H y ( jTs ) · a _ [ k - j ] + b _ y [ k ] where ā[k] is the symbol vector transmitted at instant t=kTs+i, Hy(t) the transfer function taking into account at least the transmission-reception, modulation, channel filters and the transmission-reception antenna gains and by(t) the noise, the invention proposes a two dimensional suitable estimator-demodulator.
Abstract:
A method for the detection of M0 sources common to several observations u(t) and v(t) within a single array of sensors, the observations having different lengths N1 and N2, comprises at least the following steps: defining a law of likelihood Vuv([M=M0]/M0) substantially equal to the chi-2 law with 2(N1−M0)(N2−M0) degrees of freedom with N1≦N2, dim{u(t)}=N1×1 and dim{v(t)}=N2×1; determining a detection threshold αM in order to obtain a low probability of false alarms and a number of degrees of freedom that takes account of the lengths N1 and N2 and of the number of sources M0; determining the presence and/or the number of the sources M0 in applying the law of likelihood and the threshold αM. The method and device can be applied to the determining of the presence and/or the number of sources common to at least two observations having different lengths in a GSM type radiocommunications system.
Abstract translation:用于检测在单个阵列内的若干观察结果(U STYLE =“SINGLE”> u(t)和 v(t))共同的M 0 0源的方法 传感器,具有不同长度N 1和N 2的观测值至少包括以下步骤:定义似然定律V uv([ 基本上等于具有2(N 1 -M 0)的chi-2定律的M = M 0/0 / (N 2 N 2)N N 2 N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N dim { u(t)} = N 1 x1和dim { v(t)} = N< 2& SUB> x1; 确定检测阈值αM M以便获得低概率的假警报和考虑到长度N 1和N 2的多个自由度, 2<源>和源的数量> 0< 在应用可能性定律和阈值αM M的情况下,确定源M 0 0的存在和/或数量。 该方法和装置可以应用于在GSM型无线电通信系统中确定具有不同长度的至少两个观测站共同的源的存在和/或数量。
Abstract:
A method for localizing one or more sources, said source or sources being in motion relative to a network of sensors, comprises a step for the separation of the sources in order to identify the direction vectors associated with the response of the sensors to a source at a given incidence. The method comprises the following steps of associating the direction vectors a1p(1)m . . . aKp(K)m obtained for the mth transmitter and, respectively, for the instants t1 . . . tK and for the wavelengths λp(1) . . . , λp(k), and localizing the mth transmitter from the components of the vectors a1p(1)m . . . aKp(K)m measured with different wavelengths.