Fast estimation of HF channels based on EBPSK scheme

Extended binary phase shift keying(EBPSK)is an efficient modulation mode, and HF communication is generally under the harsh transmission condition. According to the characteristic that the demodulator based on impacting filters would transform the EBPSK modulating signal into impact amplitude, a new method of HF channel estimation based on EBPSK modulation and impacting filter demodulation system is put forward. The proposed method needs no complicated process or special training sequence. Only by sending a signal “1” in communication, it would get the necessary channel parameters from the output of the impacting filter, such as the number of multipath fading, the time delay relative to mainpath, the amplitudescaling factor of each path and so on. Finally, the method is verified to be rapid, simple and effective.