DVB-T/H Signal Detection with Frequency Offset Correction

The patent applies preliminary action by estimating and correcting the frequency offset before performing the cross-correlation detection. The system first estimates the frequency offset using pilot signals and cyclic prefixes, then corrects the received signal samples accordingly. This preliminary correction ensures that the subsequent cross-correlation detection can proceed with accurate results, resolving the contradiction between detection reliability and frequency offset sensitivity.

The patent implements feedback by using the estimated frequency offset to correct the received signal, and then using the corrected signal for detection. The system continuously monitors the detection process and adjusts the frequency offset correction based on the detected signal characteristics. This feedback mechanism maintains detection reliability even in the presence of varying frequency offsets.

The patent applies feedback by implementing a sensing mechanism that continuously monitors the spectral environment. The CR device estimates the presence of primary DVB-T/H transmissions using the corrected cross-correlation method, and based on this feedback, dynamically adjusts its operation. When primary transmissions are detected, the CR device vacates the band; when the band is clear, it activates. This feedback loop enables safe spectrum sharing that prevents interference while maximizing utilization.

The patent implements self-service by enabling CR devices to autonomously sense the spectral environment and make decisions about their own operation. The devices independently perform frequency offset estimation, signal detection, and transmission decision-making without requiring centralized coordination. This self-service capability allows multiple CR devices to operate independently while avoiding interference with primary devices.

The patent applies segmentation by dividing the sensing algorithm into distinct functional modules: frequency offset estimation module, frequency offset correction module, and cross-correlation detection module. Each module performs a specific function and can be independently optimized. The frequency offset estimation uses pilot signals and cyclic prefixes, while the detection uses corrected samples. This segmentation reduces overall complexity by making each component more manageable and easier to implement.

The patent introduces frequency offset correction as an intermediary step between signal reception and detection. Instead of directly performing cross-correlation on frequency-offset corrupted signals, the system first corrects the offset using estimated values derived from pilot signals. This intermediary correction step simplifies the subsequent detection process and improves sensitivity without requiring complex adaptive algorithms.