Two iterative algorithms for blind symbol timing estimation of M-PSK signals

Carrier-blind and non-data-aided (NDA) feedforward solutions for symbol timing recovery are particularly important for initial acquisition in burst modems; the Oerder and Meyr (O&M) algorithm is perhaps the most prominent example in this respect. Since usually operated with an oversampling rate of four, alternatives using only two samples per symbol have been suggested in the open literature. On the other hand, Moeneclaey and Batsele introduced an error detector for blind NDA recovery in feedback loops, based on only one sample per symbol. In the current paper, it is shown that this approach can be successfully applied to a feedforward solution. In this context, two estimator variants are developed exhibiting no self-noise effect for M-ary PSK schemes, whereas it turns out that this does not hold true for nonconstant modulus constellations.