Cellular Base Station Interference Cancellation Using OFDM Reconstruction
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Solution Overview
Problem
Conventional RF systems are limited in their ability to mitigate cellular interference from 5G base stations, as they can only null a finite number of interfering signals, reducing target tracking efficiency and sensitivity to signals-of-interest.
Innovation Solution
A wireless signal cancellation module that reconstructs and subtracts denoised 5G OFDM waveforms from received signals on an antenna-by-antenna basis, preserving spatial degrees-of-freedom and improving sensitivity to signals-of-interest by leveraging known physical layer structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional RF systems use nulling to mitigate cellular interference, then interference from a finite number of sources is reduced, but spatial degrees-of-freedom are consumed and sensitivity to signals-of-interest deteriorates
Solution Approach 1:
The patent extracts and removes the interferer signal components from the received signal by reconstructing them using detected allocation and modulation information, then subtracting them from the original signal. This extraction approach eliminates interference without consuming spatial degrees-of-freedom, unlike conventional nulling methods.
Solution Approach 2:
The patent creates a reconstructed copy of the interferer signal based on detected allocation and modulation characteristics, then uses this copy to cancel the actual interferer by subtraction. This copying mechanism allows interference cancellation without requiring spatial nulling resources.
2Object-affected harmful factors
If conventional RF systems null interfering signals, then interference is reduced, but the number of interferers that can be mitigated is limited and target tracking efficiency decreases
Solution Approach 1:
The patent extracts interferer signal components by detecting their allocation and modulation characteristics and reconstructing them for removal. This method can handle multiple interferers simultaneously without the spatial limitations of nulling, thereby maintaining target tracking efficiency.
Solution Approach 2:
The patent transitions from spatial-domain nulling to signal-domain reconstruction by utilizing time and frequency resource allocation information. This dimensional shift allows cancellation of multiple interferers without consuming spatial degrees-of-freedom, improving target tracking efficiency.
3Duration of action of moving object
If wireless receivers process signals with cellular interference present, then signal reception continues, but interference degrades detection range and link throughput
Solution Approach 1:
The patent performs preliminary detection of interferer allocation and modulation characteristics before signal reconstruction and cancellation. This preliminary action enables effective interference removal while maintaining continuous signal reception and improving detection range and link throughput.
Solution Approach 2:
The patent converts the harmful interferer signal into a useful reconstructed signal by detecting its characteristics and using them to create an accurate copy for cancellation. This transforms the interference problem into a solvable reconstruction task, improving reliability without interrupting reception.
Data Source
AI summary
The techniques described herein relate to systems, apparatus, articles of manufacture, and methods for canceling interference from cellular base stations. An example method comprising receiving a wireless signal on a plurality of antennas at a wireless receiver, detecting an allocation and modulation of data carrying and reference signal components of the wireless signal on resources of the plurality of antennas, the resources comprising at least one of time, frequency, or spatial resources of the plurality of antennas, detecting a received symbol in the wireless signal based on the detected allocation and modulation, reconstructing, using the received symbol, a denoised symbol representing an estimate of a contribution of an interferer signal at the wireless receiver, the contribution of the interferer signal isolated from all other sources, subtracting the denoised symbol from the received symbol on an antenna-by-antenna basis to generate a residual wireless signal, and outputting the residual wireless signal.