A non-data aided carrier recovery technique using modulation format identification is proposed. This technique can also be interpreted as a modulation identification method that is robust against static phase and frequency offsets. The performance of the proposed technique is studied and analytical expressions derived for the mean acquisition time to detect lock in the cases of M-PSK, M=2,4,8, and 16-QAM modulation, with respect to frequency offset and signal-to-noise ratio. The results are verified with Monte Carlo simulations. The main advantage of the proposed method lies in its simpler implementation and faster lock detection, when compared to conventional methods.
Robert H. Morelos-Zaragoza, Kenta Umebayashi, and Ryuji Kohno. "A Method of Non-Data-Aided Carrier Recovery with Modulation Identification" Faculty Publications (2001): 3375-3379. https://doi.org/10.1109/GLOCOM.2001.966311