Abstract:
Method for formation of a signals array from a receiver (20) of signals from a satellite navigation system in order to improve the resistance to scrambling or interference, the receiver (20) being equipped with an antenna (21) having several controlled reception pattern sensors, comprising a step consisting in determining the attitude of the antenna in a TGL reference frame centred on the receiver, by iterative determination of the attitude angles of the antenna yielding the maximum of the sum of the energies of the weighted sums of the signals received by the sensors at the output of the correlators of the processing channel respectively associated with the satellites, the weighting coefficients of the weighted sums being calculated from the attitude angles considered at each iteration and from the known positions of the satellites in the TGL reference frame.
Abstract:
The invention relates to a device for receiving satellite radio-navigation signals comprising a plurality of receiving antennas forming an antenna array. The invention consists in using a plurality of antennas disposed around the circumference of a carrier and in demodulating the signals received by each antenna separately. The diversity of the demodulation chains is utilized to compensate the signal loss on one of the chains when the corresponding antenna experiences a signal loss due to the masking of the satellite by the carrier.
Abstract:
This detection method is carried out after a phase for acquiring a navigation signal during a convergence phase and comprises at least one of the following steps: —determining a plurality of pilot channel periodic correlations and a plurality of data channel periodic correlations, and determining a first value as a function of these periodic correlations; —determining a plurality of pilot channel partial correlations, and determining a second value as a function of these partial correlations; —determining a plurality of shifted pilot channel correlations, and determining a third value as a function of these shifted pilot channel correlations. The convergence phase further comprises the step for determining a wrong synchronization when at least one of the first value, the second value, and the third value exceeds a predetermined threshold.
Abstract:
This determination method for determining a wrong synchronization including the steps of determining an ad hoc correlator corresponding to the value of correlation between the received signal and the local signal, and determining N additional correlators corresponding to the values of correlation between the received signal and an offset signal, each offset signal including a spreading code that is offset in relation to the local spreading code, and determining a value for the amount of inconsistency between the frequency of the local carrier wave and the frequency of the local spreading code; if the value of inconsistency is higher than a predetermined threshold value of inconsistency, determining a wrong synchronization; otherwise, determining an indicator of wrong synchronization as a function of the correlators determined, comparing the indicator of wrong synchronization with at least one threshold value, determining a wrong synchronization based on the result of the comparison.
Abstract:
The invention relates to a device for receiving satellite radio-navigation signals comprising a plurality of receiving antennas forming an antenna array. The invention consists in using a plurality of antennas disposed around the circumference of a carrier and in demodulating the signals received by each antenna separately. The diversity of the demodulation chains is utilized to compensate the signal loss on one of the chains when the corresponding antenna experiences a signal loss due to the masking of the satellite by the carrier.
Abstract:
Method for detecting signals intended as a decoy for a receiver of signals from a satellite navigation system, the receiver being equipped with an antenna using controlled reception pattern sensors, comprising the following steps consisting in, for each satellite: calculating (1) the position of the satellite in a first TGL reference frame centred on the receiver based on the position of the receiver and on the position of the satellite; determining (2) the attitude of the antenna in the first reference frame; calculating (3) first elevation and azimuthal angles of the satellite in a second reference frame linked to the antenna, starting from the position of the satellite in the first reference frame and from the attitude of the antenna in the first reference frame; determining (4) second elevation and azimuthal angles of the satellite in the second reference frame, by iterative search for a maximum of a weighted complex sum of the demodulated signals received by the antenna; calculating (5) the value of a likelihood function between the first elevation and azimuthal angles of the satellite and the second elevation and azimuthal angles of the satellite; and detecting (6) a risk of receiving decoy signals when the said value of the likelihood function is lower than a threshold.
Abstract:
The invention relates to a device for receiving satellite radio-navigation signals comprising a plurality of receiving antennas forming an antenna array. The invention consists in using a plurality of antennas disposed around the circumference of a carrier, in demodulating the signals received by each antenna separately and then in combining the various demodulated signals, thereby amounting to effecting a beam forming in an equivalent antenna pattern. The invention then requires only a single synchronization slaving for the set of demodulation pathways.
Abstract:
A method and a function for checking the integrity of the processing of a radionavigation signal emitted by a satellite, the signal being received by a receiver comprising reception means and processing means, the processing means comprising a linear anti-interference filter, the integrity checking method comprising at least a first phase of detection of a risk of false lock-on comprising the following steps: a step of recovery of a nominal theoretical self-correlation function of the received signal not processed by the linear anti-interference filter; a step of determination of a mean theoretical self-correlation function of the signal received and processed by the linear anti-interference filter over a defined integration period; a step of determination of the number of local maxima of the modulus or of the modulus squared of the mean theoretical self-correlation function, a risk of false lock-on being detected if the number of local maxima is greater than or equal to two.
Abstract:
A technique for locating sources interfering on a signal received by a receiver comprising an array of antennas calculates a spatio-temporal intercorrelation matrix Rxx, subdivides the useful band of the signals into sub-bands (b), and for each sub-band (b), calculates the spatial intercorrelation matrix R(b) associated with the sub-band (b) and calculates at least one of its eigenvalues {λ1, λ2, . . . λM}. Interference in the sub-band is detected with the aid of the following detection criterion: log ( ( ∑ m = k M λ m ) / ( M - k + 1 ) ) - log ( ∏ m = k M λ m ) / ( M - k + 1 ) > threshold , and determining the eigenvectors {U1, U2, . . . UN} of the spatial intercorrelation matrix R(b), and determining the directions of arrival of the interfering sources by searching for the vectors of relative gains belonging to the said interference sub-space or which are orthogonal to the orthogonal noise sub-space and complementary to the interference sub-space.
Abstract translation:用于定位干扰由包括天线阵列的接收机接收的信号的源的技术计算时空相关矩阵Rxx,将信号的有用频带细分为子带(b),并将每个子带(b ),计算与子带(b)相关联的空间相关矩阵R(b),并计算其特征值{λ1,λ2,...中的至少一个。 。 。 lambdaM}。 借助于以下检测标准检测子带中的干扰:log((Σm = k Mλm)/(M-k + 1))-log(Πm = k M λm)/(M-k + 1)>阈值,并且确定特征向量{U1,U2,..., 。 。 UN},并且通过搜索属于所述干扰子空间的或与正交噪声子空间正交的相对增益的向量来确定干扰源的到达方向,以及 与干扰子空间互补。
Abstract:
A method for determining a wrong synchronization of a receiver with a satellite, associated receiver and computer program product, is implemented after the acquisition phase and includes the following steps: generating first and second test signals; for each correlation interval, determining a first prompt correlator corresponding to the correlation value between the received signal and the first test signal, and a second prompt correlator corresponding to the correlation value between the received signal and the second test signal; determining first and second energy values corresponding to the energy of the first and second correlators, respectively; determining a wrong synchronization indicator based on the difference between the first and second energy values; and detecting a wrong synchronization based on this indicator.