The present invention belongs to the technical field of communication
signal detection, and discloses a method for quickly capturing multi-rate communication signals under low
signal-to-
noise ratio, mainly solving problems such as slow
signal detection speed, single method for selecting statistics, and decreased capture ability in a low signal-to-
noise ratio environment when performing time-domain serial capture on signals with different code rates. The implementation steps are as follows: (1) pre-group the possible range of the signal
code rate; (2) sample and quantize the received signal; (3) calculate the zero-
delay slice of the
cyclic correlation of the received signal to estimate the carrier frequency of the signal; (4) intercept the processed signal, slide and select multiple
delay slices for accumulation, construct a statistic adapted to the change of the
code rate, and perform a rough
estimation of the signal
code rate; (5) according to the rough
estimation result of the code rate, select the best slice of the
cyclic correlation to obtain the accurate value of the code rate. The present invention has the advantages of high flexibility and real-time performance, fast capture speed, high capture accuracy, etc., can quickly capture signals in a low signal-to-
noise ratio complex
electromagnetic environment, and is beneficial to the establishment of a fast
communication link.