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Arturs Aboltins. Carrier Frequency Offset Estimator Based on Unique Word Cross-correlation. Riga Technical University Latvia. Contents. Communication system description; Carrier frequency offset (CFO); Estimation algorithms; Demonstration at work; Performance characteristics;.
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ArtursAboltins Carrier Frequency Offset Estimator Based on Unique Word Cross-correlation Riga Technical University Latvia
Contents • Communication system description; • Carrier frequency offset (CFO); • Estimation algorithms; • Demonstration at work; • Performance characteristics;
Possible contents of the data field • Complex-valued (QAM, QPSK, BPSK, …) samples • Discrete unitary transform of samples • Discrete Fourier Transform (OFDM-like) • Parametric transform • … Parametric communication systems
Possible contents of UW field For frequency offset estimation any determined (non-random) sequence can be used. Since the same sequences are reused for other tasks (channel estimation, timing estimation), Chu-Zadoff sequences are chosen
Up conversion Carrier frequency
CFO estimation methods • Non-data aided (blind) • Data aided (auto-correlation – AC) • Data directed (cross – correlation - XC)
Auto correlation Popular in OFDM for fractional CFO estimation problem k
Proposed XC based algorithms 1. Average increment based method 2. Least squares based method 3. Method for CAZAC sequences
SNR characteristics AWGN channel Frequency selective channel