Joint synchronization in eureka 147 DAB system based on abrupt phase change detection

We present a joint symbol, frame, and carrier synchronization method for th e Eureka 147 DAB signal in this paper. Symbol timing is determined first by detecting an abrupt change in the phase angle of the complex product betwe en the last quarter of a useful symbol and its cyclic extension in the guar d interval. The detection of this abrupt change is based on the maximal lik elihood (ML) principle. Frequency offset of fractional carrier spacing is e stimated from the phase angle of the autocorrelation after symbol timing is estimated. Coarse frame synchronization and null symbol detection can also be achieved through this correlation information Frequency offset of integ ral carrier spacing is determined from the convolution outputs between a re ceived phase reference symbol and several locally generated but frequency-s hifted phase reference symbols. We found the length of a yard interval is t he most important parameter for the synchronization algorithm to work. Simu lation results show that the performance of this synchronization method app roaches to the ideal synchronization case in both an additive white Gaussia n noise (AWGN) channel and a two-path Rayleigh fading channel.