3results about How to "Improve Spectrum Utilization Efficiency" patented technology

The application discloses a kind of full duplex antennas based on slot coupling differential feed, including two pairs of butterfly dipole antennas, first dielectric plate, four groups of vertically placed signal transmission lines, metal floor, second dielectric plate, two U-shaped feed networks and third dielectric plate;The application is placed on the upper surface and lower surface of first dielectric plate by setting two pairs of butterfly dipole antennas, to radiate horizontal polarization and vertical polarization wave, in order to generate differential signal, four T-shaped slots with the same size are etched on the metal floor, then the differential signal at T-shaped slot is transmitted to the feed position of dipole antenna by four groups of vertically placed transmission lines, and the two U-shaped feed networks are placed vertically without dielectric layer, so as to obtain larger port isolation, which can be applied to simultaneous same frequency full duplex communication system, and wireless signals can be transmitted and received simultaneously at the same frequency, thereby improving spectrum utilization efficiency.

This invention discloses a physical layer secure communication method to counter eavesdropping attacks. The communication process consists of two time slots. In the first time slot, a roadside base station selects an antenna to transmit a NOMA signal, while nearby and distant user vehicles simultaneously transmit artificial noise to interfere with the eavesdropping user vehicle. In the second time slot, the nearby user vehicle acts as a relay node, XORing the decoded distant user message with the artificial noise signal generated in the first time slot, and then sending the mixed signal to the distant user vehicle. The distant user vehicle simultaneously transmits artificial noise to interfere with the eavesdropping user. In the vehicle-to-everything (V2X) network, the nearby user, the distant user, and the eavesdropping user calculate their respective required signal-to-interference-plus-noise ratio (SIR) based on the received signals, and calculate the system user's interruption probability and interception probability. Compared with existing secure communication schemes in V2X networks, the secure communication scheme of this invention can significantly enhance the physical layer security of nearby and distant user vehicles.

This invention discloses a continuous signal processing method, system, and storage medium suitable for satellite communication. The method acquires a continuously received signal; performs coarse frequency offset estimation and compensation on the continuously received signal to obtain a frequency offset compensated signal; performs symbol timing recovery on the frequency offset compensated signal to obtain an optimal sampling sequence; performs modulation identification on the optimal sampling sequence to determine the modulation type of the optimal sampling sequence; combines the modulation type to perform fine frequency offset and carrier phase estimation compensation on the optimal sampling sequence to obtain a phase compensated sequence; performs multi-path candidate phase rotation and channel decoding decision on the phase compensated sequence, eliminates phase ambiguity using decoding convergence features, and obtains decoded data; and filters the decoded data based on a preset frame boundary flag to output valid service data. This invention can reduce physical layer frame structure overhead and improve spectrum utilization efficiency and link carrying capacity.