This paper considers the Cramer-Rao bound (CRB) for estimating the synchronization parameters from a linearly modulated waveform with unknown data symbols. The key idea is to reduce the computational complexity associated with the CRB by exploiting the specific structure of the observed signal, see e.g., [1, 2] and references therein. The current contribution builds on this previous work, but in this case, no distributional assumptions are made about the data symbols. A generalized closed-form expression of the CRB is presented, the resulting computational complexity is discussed, and numerical results are provided.