Blind Symbol Duration Estimation of Digitally Modulated Signals in the Presence of Carrier Frequency Offset

Modulation recognition and symbol duration estimation is the first step towards the exploration of the electromagnetic signals transmitted in electronic battlefields. One of the simplest procedures for blind symbol duration estimation of digitally modulated signals is done by analysis of zero-crossings of the key signal features, which are instantaneous frequency, phase, and amplitude. In this paper, a modified algorithm based on previous works is proposed for estimation of digital modulations symbol duration. The performance of the proposed algorithm is evaluated in the presence of carrier frequency offset and as the simulation results indicate, the performance of the modified algorithm is much better than the classic algorithm. As it is expected and it is shown, the robustness of this method for amplitude or frequency modulation is more than the robustness for phase modulation.