Joint channel estimation and synchronization for OFDM systems

In this paper, we present a joint channel estimation and synchronization technique for burst-mode OFDM systems. The technique uses the nonlinear recursive least squares algorithm (NL-RLS) to jointly estimate the channel impulse response (CIR), the carrier frequency offset (CFO), the sampling clock offset (SCO), and the timing offset, and to correct for each of these in the digital domain and without the use of a delay-locked loop (DLL). The need for pilot symbols in the payload data is eliminated by a decision-directed operation mode. The time-domain NL-RLS algorithm needs a small number of parameters to be estimated and can suppress the effect of decision feedback errors. Simulation results confirm its improved performance and relatively low variance.