Performance of Walsh-Hadamard codes used for timing recovery in a DVB-S2x multibeam scenario

Abstract

In Annex E of the extension to the new standard for digital video broadcasting (DVB) via satellite, usually abbreviated as DVB-S2x, Walsh-Hadamard (WH) codes are suggested as preambles of data frames. Due to their orthogonality property, WH codes are most welcome for parameter estimation and synchronization in a multibeam scenario. In the current paper, these codes are investigated with respect to symbol timing recovery. For this purpose, we focus on a low-complex estimator by using a data-aided approach without any knowledge about carrier frequency/phase, which makes the method perfectly suited for initial acquisition. It is verified that the algorithm is unbiased and that the jitter performance is close to the Cramer-Rao lower bound. Employing this theoretical figure to select the WH words of interest, we are able to circumvent cumbersome and lengthy simulation runs. Numerical results reflect different aspects of a multibeam scenario.