Title | A low complexity timing and frequency synchronization algorithm for OFDM systems |
Publication Type | Conference Paper |
Year of Publication | 2002 |
Authors | Athaudage, C. R. N., and V. Krishnamurthy |
Conference Name | Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE |
Pagination | 244 - 248 vol.1 |
Date Published | nov. |
Keywords | approximation theory, complex multiplications, computational complexity, computational cost, cyclic prefix length, discrete stochastic approximation algorithm, estimation errors, frequency estimation, frequency synchronization, minimisation, objective function minimizer, OFDM modulation, OFDM systems, self-learning capability, stochastic optimization, stochastic processes, symbol timing synchronization, synchronisation, time-varying channels, timing |
Abstract | The paper presents a low complexity discrete stochastic approximation algorithm for time and frequency synchronization in OFDM systems. The proposed technique can track the conditions of a slowly time varying channel where synchronization parameters, namely the symbol timing and frequency offset, vary slowly with time. The most important property of the proposed algorithm is its self-learning capability - it spends most of the computational effort at the global minimizer of the objective function. In particular, we show that the algorithm achieves an #949;=(1- rho;)/(1+ rho;) reduction in computational cost (in terms of complex multiplications to be performed), where rho;=Ncp/N is the ratio between cyclic prefix length (Ncp) and number of subcarriers (N) of the OFDM system (e.g. N=512 and Ncp=64 gives #949;=78%). Numerical examples illustrate the synchronization accuracy of the proposed technique in terms of symbol timing and frequency offset estimation errors. |
URL | http://dx.doi.org/10.1109/GLOCOM.2002.1188077 |
DOI | 10.1109/GLOCOM.2002.1188077 |