LNB IC Cross-Coupled Noise Cancellation via Adaptive Filtering
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Solution Overview
Problem
Satellite communications face challenges in effectively canceling cross-coupled signals in Low Noise Block (LNB) ICs, which can lead to interference and reduced signal quality.
Innovation Solution
The method involves using adaptive filters with adjustable coefficients to combine and measure satellite signals, delaying and inverting signals to cancel cross-coupling, and iteratively adjusting filter coefficients to minimize output power, implemented in a Low Noise Block IC with multiple input pins, delay modules, adaptive filter modules, and signal combiners.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adaptive filters with adjustable coefficients are used to cancel cross-coupled signals, then signal quality is improved, but device complexity increases
Solution Approach 1:
The LNB IC is divided into multiple independent signal processing paths, each handling specific satellite signals from different pins. Adaptive filters are applied individually to each pin's signal, allowing cross-coupling cancellation to be performed in a modular fashion. This segmentation enables the complex cancellation task to be broken down into manageable per-pin operations.
Solution Approach 2:
The system employs an iterative feedback mechanism where the output power of combined signals is continuously measured and fed back to adjust the adaptive filter coefficients. The coefficients are modified based on the measured power levels, and this process repeats until the output power converges to a minimum value, indicating optimal cross-coupling cancellation. This closed-loop feedback ensures high signal quality while automating the complex adjustment process.
2Reliability
If multiple adaptive filters are applied to multiple satellite signals, then cross-coupling cancellation is improved, but processing time increases
Solution Approach 1:
The system performs preliminary measurements of output power for each pin combination before full iterative optimization. By预先 measuring and identifying the dominant cross-coupling pairs, the system can prioritize which adaptive filters require adjustment, reducing the overall processing time while maintaining effective cancellation across all signals.
Solution Approach 2:
The iterative optimization process allows the system to achieve satisfactory cross-coupling cancellation with a limited number of iterations rather than requiring complete convergence. The process can be stopped when the output power reduction becomes negligible, providing a practical balance between cancellation effectiveness and processing time consumption.
Data Source
AI summary
Systems and methods for canceling cross-coupled satellite signals in a LNB IC include receiving a first satellite signal at a first pin of the LNB IC and adjusting the first satellite signal by applying a first adaptive filter to the first satellite signal signal, the first adaptive filter having first filter coefficients; combining the adjusted first satellite signal with a second satellite signal received at a second pin of the LNB IC to generate a first combined satellite signal; measuring the total output power of the combined satellite signal; changing the filter coefficients of the first adaptive filter; remeasuring the total output power of the first combined satellite signal after the changing of the first filter coefficients to determine whether the total power of the first combined satellite signal has decreased.