| 摘要 |
A signal processor comprises first 704 and second 706 discrete Fourier transform (DFT) modules, associated first 708 and second 710 detection modules which compare the power of components in the DFTs with power thresholds, a frequency correction module 712, a frequency difference module 714 and an output module 716. The first DFT module applies a first DFT of a first frame length and the second DFT module applies a DFT of a second, shorter frame length. The frequency correction module determines a correction to the frequency detected by the second DFT using the change in phase between frames. By comparing the difference in frequency detected by the first and second DFTs against a frequency threshold, the signal processor is able to distinguish short pulses which coincide with long pulses having a small difference in frequency. The carrier frequencies of the long and short pulses may also be determined. |
