Apparatus, a receiver and a method for timing recovery in an ofdm system

Abstract

An apparatus for timing recovery in an OFDM system comprises a third order phase lock loop comprising a Fast Fourier Transform stage for receiving a number of input signals in the time domain and transforming the signals to the frequency domain. A phase rotation stage adjusts the phase of one or more of the transformed signals. A frequency offset estimation stage estimates frequency offset between sampled signals and a first accumulator accumulates the frequency offset estimates. A low pass filter couplable to an output of the first accumulator stabilizes the phase lock loop. A second accumulator accumulates outputs of the low pass filter and controls phase rotation in the phase rotation stage. A controller controls timing associated with the window of operation of the Fast Fourier Transform process and is itself controlled by the second accumulator. There is also disclosed a receiver comprising the above apparatus and a method for timing recovery in an OFDM system.