36 results about "Direction finding algorithms" patented technology

Repeated data packets are generated from a first Bluetooth enabled device to a second Bluetooth enabled device to facilitate radio direction finding of the first device by the second device. A communication connection is established between the first and second devices in accordance with a Bluetooth protocol stack and in response to receiving at the second device a data packet transmitted by the first device the second device transmits an NACK data packet to the first device, whereby the first device is cause to retransmit said data packet, and causing the second device to process at least one of the transmitted data packet and the retransmitted data packet in accordance with a radio direction finding algorithm. The communication connection preferably comprises a remote name request.

The invention provides a direction finding algorithm for an unmanned platform based on four antennas. Based on the physical waveform of communication transmission, two sets of binary antennas perpendicular to each other are used to complete the measurement of the direction of the incident signal. The method obtains the incident signal through two sets of binary antennas The direction and the ambiguity of the azimuth are eliminated, and the optimal estimation of the azimuth of the two groups of antennas is ensured by comparing the judgment and error compensation. By combining the unmanned platform inertial navigation equipment, the incident signal azimuth estimation error caused by the platform's own motion is compensated. The invention can provide direction finding information support for realizing precise relative positioning between platforms.

The invention belongs to the technical field of communication radar. An equilateral triangular array is selected as a rough measurement array in a circular array, the phase difference between two baselines in a triangular matrix is calculated, and possible actual phase differences are exhaustively listed according to the maximum ambiguity degree; the possible actual phase differences are substituted to a circular array phase difference solving formula to build a phase difference vector sample library; the ambiguity degree of the actual circular array phase difference is obtained by a related operation, and further an actual circular array phase difference vector is obtained; and finally, an incident angle value as an accurate DOA (Direction of Arrival) estimate is inversely solved by finding the least squares solution of direction cosine. The novel phase interferometer two-dimensional direction finding algorithm for ambiguity resolution by extension baselines is applied, so that higher precision can be obtained compared with a direction finding algorithm based on a related operation, and the required amount of computation is greatly reduced. The method is a high-performance angle measurement algorithm.

The invention discloses a channel inconsistency error correction direction finding method for channel state information, and belongs to the technical field of indoor positioning. The method comprisesthe following steps: modeling a CSI direction finding algorithm; calculating direct wave time of flight ToF by using the single antenna data; smoothing the CSI data between the paired antennas to increase the aperture of the receiving array; carrying out amplitude-phase error calculation between paired antennas by using the direct wave time of flight ToF and the direct wave incident angle prior information; and establishing an amplitude-phase error table under different incoming wave directions according to offline data, dynamically selecting a gamma value according to the table in an online process, and performing channel amplitude-phase error correction and iterative direction finding. According to the invention, a complex inter-channel amplitude-phase error correction problem of a commercial Wi-Fi network card is solved; the CSI direction finding precision of the Wi-Fi network card is ensured, the complexity and cost of deployment and use of the indoor positioning system based on the commercial Wi-Fi network card are effectively reduced, the application prospect is wide, the operation is simple, special equipment is not needed, and the method can effectively adapt to an indoor multipath environment.

The invention discloses a direction finding device for a phase interferometer and a phase spectrum interferometer based on an orthogonal / non-orthogonal multiple baselines. According to direction-finding algorithms of the phase interferometer and the phase spectrum interferometer, the direction finding device is designed by integrally considering factors such as an actual direction-finding environment, the frequency range of an incident signal, the direction-finding requirement, hardware sources and the like. According to the direction finding device, the processing of a digital signal is cooperatively finished by two FPGAs (Field Programmable Gate Array) and a DSP (Digital Signal Processor); and two direction-finding algorithms of the phase interferometer and the phase spectrum interferometer based on the orthogonal / non-orthogonal multiple baselines are realized respectively for a narrow frequency band single-source signal and a wide frequency band multi-source signal. The direction finding device has the advantages of simple algorithm, high speed of calculation, higher direction finding precision and lower requirement on hardware resources; and the direction finding device can be used in application occasions such as quick acquisition of two-dimensional arrival direction of a single-source or multi-source signal and the like.

Disclosed is a position estimation method for estimating a position of an interference signal source and a position estimation system for performing the method. The position estimation method may implement an indoor delay-space analysis structure by transmitting and receiving a known signal and a virtual array structure-based direction finding algorithm in an indoor environment in which a plurality of reflected waves is present and may increase an estimation probability for the position of the interference signal source.