Interference Cancellation Repeater Using Adaptive Filter Selection
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Solution Overview
Problem
Existing repeaters face performance deterioration and oscillation due to insufficient separation distance between donor and service antennas, leading to ineffective interference cancellation in received signals.
Innovation Solution
An interference cancellation repeater that detects a synchronization signal to select one of multiple adaptive filters, using the selected filter to cancel interference in the received signal, operating in a time division duplex (TDD) scheme with separate adaptive filter coefficients for uplink and downlink communication periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single adaptive filter is used for interference cancellation, then the device complexity is reduced, but the interference cancellation effectiveness deteriorates during fast switching between uplink and downlink communications
Solution Approach 1:
The single adaptive filter is segmented into multiple adaptive filters (first adaptive filter for uplink, second adaptive filter for downlink). Each filter is specialized for specific communication directions, improving cancellation effectiveness during TDD switching while maintaining manageable complexity through dedicated functionality.
Solution Approach 2:
The system dynamically selects and switches between different adaptive filters based on the current communication period (uplink or downlink). The controller activates the appropriate filter according to TDD configuration, enabling the system to adapt to fast switching requirements without requiring a completely complex multi-filter architecture to always be active.
2Reliability
If separate adaptive filters are used for uplink and downlink communication periods, then the interference cancellation effectiveness is improved, but the device complexity increases
Solution Approach 1:
Different adaptive filters are designed with locally optimized characteristics suitable for their specific communication direction. The first adaptive filter is optimized for uplink interference cancellation while the second is optimized for downlink, allowing each to have specialized parameters and structures tailored to their specific operational context.
Solution Approach 2:
Multiple adaptive filters share common functional architecture and control mechanisms, allowing them to serve different communication directions while maintaining a unified system framework. The controller universally manages filter selection and switching, reducing overall system complexity despite having multiple specialized filters.
3Reliability
If adaptive filter coefficients are updated frequently to track fast switching, then the interference cancellation effectiveness is improved, but the loss of time for coefficient updates increases
Solution Approach 1:
Adaptive filter coefficients are pre-calculated and prepared for different communication scenarios before switching occurs. The system maintains multiple sets of coefficients corresponding to different TDD configurations, allowing immediate activation without real-time calculation delays during actual switching events.
Solution Approach 2:
The coefficient management process merges update operations across multiple filters, where coefficients can be updated in batches or shared between filters when appropriate. This reduces the total time required for coefficient updates compared to independently updating each filter separately.
Data Source
AI summary
Provided are an interference cancellation repeater capable of selecting one of a plurality of adaptive filters based on a synchronization signal and canceling interference included in a received signal using the selected adaptive filter and a method of operation thereof.