Satellite Receiver Interference Cancellation via Dual-Receiver Synchronization
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Solution Overview
Problem
Communication receivers face interference issues due to overlapping frequency bands, particularly from terrestrial systems like WiMAX networks affecting satellite systems, where existing methods are inadequate in effectively canceling interference and recovering desired signals.
Innovation Solution
A method and system utilizing two receivers synchronized to a common frequency and timing reference, one for the desired signal and another for the interfering signal, jointly processing outputs to decode and reconstruct the desired signal while suppressing interference, using techniques such as successive cancellation and weighted sum processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single receiver is used to receive signals in overlapping frequency bands, then the device complexity is low, but the ability to cancel interference and recover desired signals deteriorates
Solution Approach 1:
The receiver is divided into two separate receivers: a first receiver configured for the first air interface and a second receiver configured for the second air interface. Each receiver independently processes signals according to its specific air interface protocol, enabling effective interference cancellation by separately decoding the desired signal and interfering signal before combining their outputs.
2Reliability
If two receivers are used to decode desired and interfering signals separately, then the interference cancellation capability is improved, but the device complexity increases
Solution Approach 1:
The outputs of the first and second receivers are jointly processed through a combining operation that adds the decoded desired signal from the first receiver with the decoded interfering signal from the second receiver. This merging of output signals enables effective interference cancellation while reusing common components such as the frequency and timing reference unit.
Solution Approach 2:
The frequency and timing reference unit serves both the first receiver and the second receiver simultaneously, providing a common synchronization reference for both air interfaces. This multi-functional component reduces overall system complexity by eliminating the need for separate reference generation circuits in each receiver.
3Productivity
If traditional single receiver methods are used, then the device simplicity is maintained, but the spectral efficiency and capacity deteriorate due to interference
Solution Approach 1:
The system employs feedback mechanisms where the decoded interfering signal from the second receiver is fed back into the combining operation to cancel its effect on the desired signal. This feedback loop continuously refines the interference cancellation process, improving spectral efficiency by enabling reliable signal recovery in the presence of strong interfering signals.
Data Source
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AI summary
A method for communication includes receiving a Radio Frequency (RF) channel containing a desired signal conforming to a first air interface and an interfering signal conforming to a second air interface. A first receiver (52) configured for the first air interface and a second receiver (56) configured for the second air interface are synchronized to a common frequency and timing reference (84). While the first and second receivers are synchronized, the desired signal is decoded from the RF channel using the first receiver to generate a first output, the interfering signal is decoded from the RF channel using the second receiver to generate a second output, and the desired signal is reconstructed while suppressing the interfering signal by jointly processing the first and second outputs.