A Rapid Joint Semi-blind Estimation Algorithm for Carrier Phase and Timing Parameter

Multi-path effect in HF communication not only changes the amplitude, but changes the phase of receiving signal as well. The rapid and random movement of ionospheric causes the oscillation of the phase. It could be viewed as the Doppler shift of high-frequency carrier caused by ionospheric. The shift of frequency should be corrected because it brings difficulty in recovering the carrier. The non-blind method needs much quantities of training (or pilot frequency) sequences at the cost of system recourse (bandwidth). However, the blind estimation will wildly encounter the vague phase. In this paper, a semi-blind parameter estimation method is introduced which uses few training sequences to distinguish the carrier. In this way, the carrier's phase and timing parameter could be recovered rapidly. Besides, this algorithm is easy to implement in hardware platform.