The application discloses a high-sensitivity fast acquisition method and
system in a star-ground dynamic environment, and the method comprises the following steps: S1, a transmitting end transmits a communication
signal conforming to a target communication frequency, and a receiving end receives the communication
signal; S2, a plurality of local signals with different frequency points are generated in a frequency search interval through a local parallel
digital control oscillator (NCO) group, and FFT-IFFT acquisition determination is performed on the communication
signal; S3, if the acquisition determination fails, the frequency search interval is adjusted, and the step S2 is performed again; if the acquisition determination fails in two adjacent frequency search intervals,
sideband interval estimation is performed on the two adjacent frequency search intervals, and FFT-IFFT acquisition determination is performed according to the
sideband interval estimation result; the step is repeated until the acquisition determination succeeds. Under the conditions that the detection probability is more than 99%, the minimum carrier-to-
noise ratio is 34.66 dB, and the minimum signal-to-
noise ratio is 16 dB, the
receiver sensitivity of-130
dBm can be realized, the total
Doppler frequency offset acquisition range can reach 140 kHz, and the
acquisition time can be as low as 0.8 seconds.