Joint synchronization of symbol timing and carrier frequency using the extended zero-crossing property

In a recently published paper, a novel approach for blind feedback synchronization of the symbol timing has been proposed. In order to avoid any jitter floor irrespective of the selected modulation scheme, a filter with very particular properties has been developed and placed in parallel to the receiver matched filter. Nevertheless, the jitter performance of this method degrades in case the carrier frequency offset does not vanish. Therefore, joint synchronization of symbol timing and carrier frequency will be studied in the current paper, based on the dual-filter framework developed in some previous works. To this end, we introduce a very simple frequency error detector, which is analyzed in terms of open-loop characteristic (S-curve) and jitter variance, forming this way the ground for joint recovery.