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AssigneeDeutsche Thomson-Brandt GmbH
InventorsOtto Klank, Dominique Madeleine
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Various methods for terrestrial transmission of digital broadcast signals as DVB, HDTV-T and DAB signals are known. One of these methods is the OFDM method, where the transmitted signal includes a multiplicity of modulated carriers. These carriers are separated in the receiver by means of a Fast Fourier Transformation (FFT). Before being transposed in the frequency domain by the FFT, the analog signal must be sampled. For this purpose a local oscillator controls the timing in front of the FFT. Oscillator imperfections like jitter and frequency offsets can degrade the accuracy of the sampling operation and therefore introduce intercarrier interferences after the FFT. A feedback loop combining the AFC and CPEE process has been designed in order to correct frequency deviations and to reduce jitter of the signal without introducing significant phase noise.
In apparatus for processing multicarrier signals, a method of frequency correction comprising:
Method according to claim 2, characterized in that the first (AFC) and second (CPEE) process are performed after separation of the various carriers of the multicarrier signal and the results are used to correct the baseband signal in front of the carrier separation.
In apparatus for processing multicarrier signals, a method of carrier frequency correction comprising:
In a system for processing a multicarrier signal including an OFDM signal comprising CAZAC-Sequences, M-Sequences and pilot symbols, a method for the frequency correction of such multicarrier signal comprising:
Apparatus for the frequency correction of multicarrier signals comprising:
Dependencies are inferred from the claim text.