Design and analysis of pulse-shaped space-time block code based symbol timing recovery algorithms

A method for the design of low complexity timing error detectors (TEDs) for orthogonal and quasi-orthogonal space-time block coding (OSTBC and QOSTBC) receivers is presented. It is shown that a difference of threshold crossings timing estimate can be obtained for a two-transmit antenna OSTBC receiver in a frequency-flat Rayleigh fading environment. The S-curve of the resulting TED possesses an important property of robustness to channel fading. The results are generalized by the development of a TED design framework for higher order OSTBCs and the derivation of sufficient conditions for a robust difference of threshold crossings timing estimate. The designed detectors inherently depend on the properties of the spacetime block code under consideration. As such, particular OSTBCs can be regarded as self-synchronizing. Analytical expressions for the S-curve, estimation error variance and the signal-to-noise ratio of detectors for arbitrary OSTBCs are obtained. We design and evaluate the properties of a number of timing estimators for some known space-time block codes. Performance results are examined through system simulations, where the timing drift tracking capabilities of the detectors within a timing loop of an OSTBC receiver are investigated. While the theoretical derivations assume a receiver with perfect channel state information and symbol decisions, simulation results include performance for a receiver employing pilot symbol-based channel estimation and data symbol detection.