Systems, methods, and media for generating pre-correlation phase coherent samples that can be used with coherent integration for signal detection

A method for generating pre-correlation phase coherent samples for signal detection, the method comprising:

• creating, by processor coupled to a memory of a computing device, a plurality of sub-buffers, each sub-buffer including an equal number of samples of signal data;
• and
• testing, by the processor, each of a plurality of different Doppler remainders by:
• selecting, for a Doppler remainder being tested, a sub-buffer of the plurality of sub-buffers as a reference sub-buffer;
• phase rotating each other sub-buffer, of the plurality of sub-buffers, a different multiple of a value of the Doppler remainder being tested,
• wherein the phase rotation between any two consecutive sub-buffers, of the plurality of sub-buffers, is equal to the value of the Doppler remainder being tested;
• and
• accumulating the plurality of sub-buffers, that include the reference sub-buffer and each of the other sub-buffers that is phase rotated, to generate a pre-correlation accumulation (PCA) output for the Doppler remainder being tested, wherein the PCA output is generated for each of the plurality of different Doppler remainders being tested.

A non-transitory computer readable medium having software encoded thereon, the software when executed by one or more computing devices operable to:

• generate, prior to coherent integration, a pre-correlation accumulation (PCA) output for each of a plurality of different test Doppler remainders corresponding to an unknown Doppler shift;
• determine that a particular PCA output, which is used for the coherent integration, is associated with a correlation peak that meets a predefined threshold;
• determine a phase of a differential correlation peak that is based on the correlation peak;
• and
• estimate the unknown Doppler shift using the phase of the differential correlation peak, a sample rate, and a differential delay in samples.