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Cyclic delay diversity (CDD) is a simple technique to intentionally increase frequency selectivity of channels for orthogonal frequency division multiplexing (OFDM). This letter evaluates the performance of post-FFT fine frequency estimation scheme for OFDM-based FM system using CDD. A new and accurate mean square error expression of the fine frequency estimator is derived in the CDD-based OFDM system, and simulation results are provided to verify our analysis.
In order to improve the synchronization performance of the OFDM-based FM broadcasting system, this letter addresses the problem of delay selection when the system uses a cyclic delay diversity (CDD) scheme. By proper selection of the amount of cyclic delay, an improved fine carrier frequency offset estimator is derived. By computer simulation, the proposed estimator is shown to benefit from properly chosen delay parameter and perform robustly.
Won-Jae SHIN Ki-Won KWON Yong-Je WOO Hyoungsoo LIM Hyoung-Kyu SONG Young-Hwan YOU
In this letter, a robust algorithm for jointly finding an estimate of the start of the frame and transmission mode is proposed in a digital audio broadcasting (DAB) system. In doing so, the use of differential-correlation based joint detection is proposed, which considers not only the height of correlation peak but also its plateau. We show via simulations that the proposed detection algorithm is capable of robustly detecting the start of a frame and its mode against the variation of signal-to-noise ratio, providing a performance advantage over the conventional algorithm.
Won-Jae SHIN Young-Hwan YOU Moo-Young KIM
In this letter, an improved residual symbol timing offset (STO) estimation scheme is suggested in an orthogonal frequency division multiplexing (OFDM) based digital radio mondiale plus (DRM+) system with cyclic delay diversity (CDD). The robust residual STO estimator is derived by properly selecting the amount of cyclic delay and a pilot pattern in the presence of frequency selectivity. Via computer simulation, it is shown that the proposed STO estimation scheme is robust to the frequency selectivity of the channel, with a performance better than the conventional scheme.
In this letter, we present a low-complexity residual symbol timing offset (STO) estimation scheme in a long term evolution (LTE) downlink system. The proposed scheme is designed to estimate STO without a priori knowledge of cell-specific reference signals, which reduces the arithmetic complexity while maintaining a similar performance to the conventional algorithm.