Low-complexity fast acquisition technique with minimal snr loss

A user equipment (UE) comprising:

• a processor;
• and
• a non-transitory computer readable storage medium storing instructions that, when executed, cause the processor to:
• receive a signal including a reference code;
• generate a plurality of frequency hypotheses across a Doppler frequency range associated with the signal;
• rotate the signal using a composite signal formed by summing time sections of sinusoidal tones corresponding to the plurality of frequency hypotheses;
• downsample the rotated signal;
• apply a respective phase correction to the downsampled signal for each of the plurality of frequency hypotheses to produce a plurality of phase-corrected signals;
• correlate each phase-corrected signal with the reference code to detect the signal that includes the reference code and generate a plurality of correlation outputs;
• and
• select a frequency hypothesis of the plurality of frequency hypotheses and a code phase based on a maximum value among the correlation outputs.

A method of acquiring a signal in a receiver, comprising:

• rotating a received signal using a composite signal based on a plurality of Doppler frequency hypotheses;
• applying a respective phase correction to the rotated signal for each of the plurality of Doppler frequency hypotheses to generate a plurality of phase-corrected signals;
• and
• determining a Doppler frequency hypothesis associated with the received signal based on the phase-corrected signals.