A symbol timing recovery scheme based on spectral redundancy

It is well known that digital modulation systems of the QAM family exhibit cyclostationary behaviour, which makes symbol timing recovery (STR) possible from a signal which has no discrete spectral component at the symbol rate. The literature on the subject, however, describes only algorithms which operate in the time domain. The authors try to show that a frequency domain analysis brings out the effects of spectral redundancy, and in so doing leads to algorithms and implementations which are not only simpler to understand, but also require lower hardware complexity. The three principal types of maximum likelihood estimator are discussed. The authors describe a timing recovery algorithm based on direct computation