Satellite Receiver Frame Detection Using Shaping Filter Preprocessing
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Solution Overview
Problem
Current satellite communication systems face challenges in detecting the start of a frame, especially in packet transmission modes, leading to complex and expensive receiver devices with high error rates, particularly in low Earth orbit and high mobility contexts.
Innovation Solution
A method and receiver device that utilize a preamble with binary symbols for frame detection, involving sampling, shaping filtering, frequency error estimation, and correlation calculations to simplify the hardware complexity by applying shaping filters before frequency correction and reducing the number of correlators needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods are used to detect frame start in packet transmission, then reliability is improved, but device complexity increases significantly
Solution Approach 1:
The patent applies preliminary action by performing shaping filtering on the received signal before frequency correction and correlation operations. This preprocessing step prepares the signal in advance, making subsequent frame detection more reliable while reducing the complexity of the overall system architecture.
Solution Approach 2:
The patent changes the processing sequence parameter by applying shaping filtering before frequency correction, contrary to conventional approaches. This parameter change in the signal processing chain enables simplified hardware architecture while maintaining detection reliability through optimized correlation calculations.
2Reliability
If multiple correlators are used to ensure reliability, then frame detection reliability is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and processes only the necessary portions of the signal for frame detection by applying shaping filtering that emphasizes the preamble structure. This allows reliable frame start detection using fewer correlators, as the preprocessing concentrates the relevant signal features.
Solution Approach 2:
The patent uses a simplified correlation approach that copies only the essential preamble pattern for comparison, rather than using multiple full correlators. The shaping filtering prepares the signal to match the expected preamble structure, enabling reliable detection with reduced hardware.
3Ease of manufacture
If shaping filtering is applied after frequency correction, then conventional signal processing is maintained, but hardware complexity increases
Solution Approach 1:
The patent performs shaping filtering as a preliminary action before frequency correction and correlation operations. This reordering simplifies the hardware architecture by preparing the signal in advance with appropriate filtering characteristics, reducing the complexity of subsequent processing stages.
Data Source
AI summary
A method and a receiver device for detecting the start of a frame of a satellite communication signal. A shaping filtering is applied directly after sampling of the signal, before a frequency correction is applied. During a first phase, an approximate frequency error and a candidate first sample for the start of the frame are estimated by performing several correlations respectively associated with different frequency hypotheses. The samples obtained after sampling or after shaping filtering are buffered during the execution of the first phase. Then, during a second phase, a final candidate sample for the start of the frame is determined from the memorised samples, using the approximate frequency error and the candidate first sample estimated during the first phase.