Method, system and storage medium of signal acquisition based on selective coherent integration for anti-jam of protected global positioning system user equipment

A system, comprising:

• a memory, configured to store program instructions for performing a signal acquisition method based on selective coherent integration (SCI) for anti-jam of protected global positioning system (GPS) user equipment;
• and
• a processor, coupled with the memory and, when executing the program instructions, configured for:
• establishing a sub-integration length of a prime code signal to be a half of a symbol duration of navigation data, wherein the prime code signal is received by a signal receiver and includes a plurality of sub-integration pairs, and each sub-integration pair includes a first sub-integration and a second sub-integration;
• for each sub-integration, generating a first local replica and a second local replica based on the prime code signal, wherein the first local replica does not include navigation data, and the second local replica includes navigation data which incorporates negative data values on all corresponding odd chips;
• and executing fast Fourier transform (FFT) based convolution on the prime code signal, the first local replica and the second local replica to yield two convolution results;
• comparing two convolution maximum peak values respectively corresponding to two convolution results of the first sub-integration and selecting a convolution maximum peak value with higher magnitude in the first sub-integration as a first convolution peak value;
• and comparing two convolution maximum peak values respectively corresponding to two convolution results of the second sub-integration and selecting a convolution maximum peak value with higher magnitude in the second sub-integration as a second convolution peak value;
• and
• comparing the first convolution peak value and the second convolution peak value;
• selecting the first convolution peak value if the first convolution peak value is greater than or equal to the second convolution peak value, and executing inverse fast Fourier transform (IFFT) based convolution on a convolution result corresponding to the first convolution peak to obtain an IFFT convolution result to be outputted;
• and selecting the second convolution peak value if the first convolution peak value is less than the second convolution peak value, and executing inverse fast Fourier transform (IFFT) based convolution on a convolution result corresponding to the second convolution peak to obtain an IFFT convolution result to be outputted.

A non-transitory computer-readable storage medium, containing program instructions for, when being executed by a processor, performing a signal acquisition method based on selective coherent integration (SCI) for anti-jam of protected global positioning system (GPS) user equipment;

• the method comprising:
• establishing a sub-integration length of a prime code signal to be a half of a symbol duration of navigation data, wherein the prime code signal is received by a signal receiver and includes a plurality of sub-integration pairs, and each sub-integration pair includes a first sub-integration and a second sub-integration;
• for each sub-integration, generating a first local replica and a second local replica based on the prime code signal, wherein the first local replica does not include navigation data, and the second local replica includes navigation data which incorporates negative data values on all corresponding odd chips;
• and executing fast Fourier transform (FFT) based convolution on the prime code signal, the first local replica and the second local replica to yield two convolution results;
• comparing two convolution maximum peak values respectively corresponding to two convolution results of the first sub-integration and selecting a convolution maximum peak value with higher magnitude in the first sub-integration as a first convolution peak value;
• and
• comparing two convolution maximum peak values respectively corresponding to two convolution results of the second sub-integration and selecting a convolution maximum peak value with higher magnitude in the second sub-integration as a second convolution peak value;
• and
• comparing the first convolution peak value and the second convolution peak value;
• selecting the first convolution peak value if the first convolution peak value is greater than or equal to the second convolution peak value, and executing inverse fast Fourier transform (IFFT) based convolution on a convolution result corresponding to the first convolution peak to obtain an IFFT convolution result to be outputted;
• and selecting the second convolution peak value if the first convolution peak value is less than the second convolution peak value, and executing inverse fast Fourier transform (IFFT) based convolution on a convolution result corresponding to the second convolution peak to obtain an IFFT convolution result to be outputted.