8 results about "Skywave" patented technology

This invention discloses a method for adjusting the active port, calculating the interruption probability, and calculating the interruption rate of shortwave communication based on a manifold antenna system in the field of wireless communication technology. The method includes: obtaining the architectural parameters of the target manifold antenna system, which include N ports uniformly distributed along a linear dimension W, each port sharing a common radio frequency link; calculating the instantaneous channel gain of each port; and selecting the port with the maximum instantaneous channel gain as the active port for shortwave communication. By introducing a manifold antenna, this invention achieves dynamic spatial adaptability within a limited area. Unlike traditional arrays with static elements, the FAS utilizes spatial diversity through real-time reconfiguration of antenna positions, eliminating the need for multiple radio frequency links. It also utilizes ionospheric reflection to establish beyond-line-of-sight connections. The FAS dynamically adjusts its active port to optimize reception from different refraction points, mitigating the inherent fading and signal attenuation of high-frequency skywave channels.

This invention proposes a range estimation method for skywave over-the-horizon radar based on a sparse Bayesian algorithm. The implementation steps are as follows: beamforming is performed on the data received by the skywave over-the-horizon radar antenna array; pulse compression and moving target detection are performed on the echo data from the target's azimuth to obtain the range-Doppler matrix; two-dimensional constant false alarm rate (CFAR) detection is performed on the range-Doppler matrix; and the target's range information is obtained by sparse recovery of the echo data from the Doppler channel using the sparse Bayesian algorithm. This invention can improve the range resolution and range estimation accuracy of skywave over-the-horizon radar; it reduces the computational load and system complexity of the algorithm, making it more suitable for engineering applications.

This invention proposes a frequency selection method and system for massive MIMO skywave communication based on ionospheric maps, addressing the problems of limited channel capacity, low signal-to-noise ratio, and the strong frequency selectivity of the ionosphere, which makes it difficult to support multi-user access in skywave communication. The method includes: acquiring historical ionospheric observation data to construct an ionospheric map; calculating the azimuth and elevation angles between the base station and each user based on the geographical location information of the base station and each user; determining the location of the ionospheric reflection point based on the elevation angle and obtaining the critical frequency by querying the ionospheric map, thereby determining the carrier frequency range corresponding to the user's elevation angle; within the carrier frequency range, establishing a joint optimization model of the carrier frequency and precoding vector, and solving for the optimal carrier frequency and the corresponding precoding scheme. This invention can effectively improve the multi-user transmission rate and spectrum utilization efficiency of massive MIMO skywave communication systems and is suitable for high-reliability long-distance communication scenarios in complex ionospheric environments.

This invention relates to radar target detection and tracking technology. To address the limitations of traditional particle filtering over long-term accumulation, it provides a pre-detection tracking method for skywave over-the-horizon radar. This method divides virtual frames and velocity intervals using motion constraints to obtain multiple parallel processing channels, thereby narrowing the coherent pulse number estimation interval and performing coherent processing. Simultaneously, before particle filtering, the constant false alarm rate (CA-CFAR) method ensures that particles are randomly generated only in range-Doppler cells exceeding a threshold, further reducing the particle number. This invention reduces computational load while improving the detection and tracking capabilities of OTH radar for weak targets. This invention combines echo data preprocessing with coherent and non-coherent processing techniques, improving the detection and tracking performance of weak targets in skywave over-the-horizon radar while reducing computational complexity through multi-channel and low-threshold methods.

This invention relates to the field of shortwave antenna communication channel testing and modeling technology, specifically to a method for measuring the angular power spectrum of an antenna in a shortwave skywave scenario. The method includes: the receiver performing a two-dimensional equally spaced angular scan within a preset azimuth and elevation range; establishing an angular power spectrum measurement equation based on the received signal power, antenna pattern, and noise power channel, using the scattering function; convolving this equation with the pattern to obtain the angular power spectrum within a single path; discretizing the single-path received power matrix and antenna pattern matrix in two dimensions, and then performing zero-plugging expansion on each; converting the discretized single-path received power matrix and antenna pattern matrix into two-dimensional frequency domain matrices, and determining the frequency domain ratio between the received power matrix and the antenna pattern matrix mapped to the angular domain using time-delay Doppler domain parameters. This invention improves the accuracy of angular power spectrum measurement in shortwave skywave channels while reducing the dependence of traditional empirical modeling methods on a single propagation assumption.

A method for detection of a skywave symbol, the method may include receiving, by a skywave propagation receiver, received signals that are within a skywave frequency range that comprises legal subcarriers and illegal subcarriers; and detecting a reception of the skywave symbol based on at least one energy parameter related to at least two out of (a) received signals at the illegal subcarriers, (b) received signals at the legal subcarriers, (c) received signals at any of the subcarriers.

The invention discloses a method, a device and equipment for tracking sky wave radars before networking detection, and a storage medium. The method comprises the following steps: acquiring radar measurement information and gate result information of a target object detected by each sky wave radar in a sky wave radar networking system at each moment and each frame according to a preset sliding window length; associating radar measurement information and gate result information of each frame of sky wave radar detection at each moment, and establishing a data association event space; according to each associated event, calculating a posterior probability cumulative value of each associated event and estimating state prediction information of each associated event; and determining the track of the target object according to the posterior probability cumulative value of each associated event and the state prediction information of each associated event, thereby solving the technical problem that the target track is difficult to track due to low target measurement detection probability and high false alarm probability under the condition of low target signal-to-noise, and improving the target track tracking efficiency. And tracking of the target track is realized.

The application relates to the technical field of short-wave radio, in particular to a short-wave sky wave signal angle-of-arrival-polarization information estimation method and device, wherein the method comprises the following steps: receiving a short-wave sky wave signal by using a preset short-wave three-component polarization receiving antenna array; based on a rank-deficient MUSIC algorithm and a multi-core parallel operation optimization strategy, performing corresponding array signal processing, signal source number estimation and multi-stage spectrum peak search operation in a preset DSP processor to obtain short-wave sky wave signal angle-of-arrival estimation information and polarization angle estimation information. According to the electromagnetic vector receiving antenna array and the DSP processing method, the sky wave signal angle-of-arrival and polarization information are estimated at the same time, so that the sky wave signal accurate direction finding, the signal quality improvement and the ionospheric wave propagation environment research are provided with the basis.