2results about How to "Good autocorrelation" patented technology

This invention discloses a high-security ranging code design method based on a pseudosatellite system. It utilizes a Legendre polynomial sequence based on quadratic residue theory, incorporating truncation point parameters and phase difference parameters. A Weil code is generated through a shift-and-XOR operation. The generated Weil code sequence is then used to generate the primary ranging code sequence through cyclic truncation and splitting operations. A periodic code-changing scheme is introduced to further enhance the security of this code sequence. This invention improves the security performance of the ranging code without significantly affecting its correlation, making it more suitable for scenarios with high confidentiality and correlation requirements.

This invention discloses a method and system for integrating low-Earth orbit satellite coverage enhancement through codeword overlay in the code domain. It utilizes orthogonal time-frequency spatial demodulation technology to modulate the communication and navigation fusion signal onto a corresponding carrier to form a time-domain signal. A pseudo-random sequence is added before the time-domain signal as training symbols before transmission. The channel impulse response in the time-delay-Doppler domain is reconstructed, and the distance between the satellite and the ground receiver is measured using the training symbols for positioning calculation before being deleted. The received signal is converted from the time domain to the time-frequency domain using orthogonal time-frequency spatial demodulation technology, and signal equalization is performed based on the channel impulse response. The probability of all users transmitting all codewords is calculated. Navigation message information is read to obtain satellite operating status, satellite coordinate information, and navigation message information from at least four satellites. Combined with the obtained distance information, the receiver position is calculated. This addresses the problems of relatively isolated development and low integration efficiency of satellite communication and satellite navigation systems.