An improved combined symbol and sampling clock synchronization method for OFDM systems

In this paper, we present a delay-locked loop (DLL) technique for performing a combined symbol and sampling clock synchronization in orthogonal frequency division multiplexing (OFDM) systems. In addition, we propose a symbol timing acquisition algorithm for the DLL. It is shown that by using this combined scheme, we can achieve symbol timing recovery and sampling clock adjustment simultaneously. In particular, the symbol timing estimation error variance can be decreased by several orders of magnitude compared with the common correlation methods in both the AWGN and multipath fading channels