Dual-Polarization MIMO Signal Separation via Analog Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dual-polarization MIMO systems face challenges in efficiently separating orthogonally polarized signals after transmission through a common medium, as existing methods require costly and space-consuming band-pass filters.
Innovation Solution
The use of analog interference cancellation and notch filters or N-path filters to isolate and separate dual-polarized signals, allowing for the derivation and processing of constituent polarized signals using a single filter, thereby reducing resource and area consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If band-pass filters are used to separate dual-polarized signals, then signal separation is achieved, but cost and device area increase significantly
Solution Approach 1:
The patent combines the functions of multiple band-pass filters into a single filter by using analog interference cancellation. The system uses one filter to derive one polarized signal while generating an out-of-phase version to cancel the other signal, merging what would traditionally require two separate filters into a single filter implementation, thereby reducing device area.
Solution Approach 2:
The patent introduces an intermediary mechanism (analog interference cancellation circuitry) that mediates between the single filter and the dual-polarized signal separation task. This intermediary generates delayed and phase-inverted versions of the filtered signal to cancel unwanted components, enabling separation functionality without requiring multiple physical filters.
2Measurement precision
If band-pass filters are used to separate dual-polarized signals, then signal separation is achieved, but manufacturing cost increases
Solution Approach 1:
The patent merges multiple filter functions into a single filter implementation combined with analog interference cancellation circuitry. This reduction from two filters to one filter directly reduces component costs, PCB real estate, and assembly complexity, thereby lowering manufacturing costs while maintaining signal separation capability.
Solution Approach 2:
The system creates a copied and phase-inverted version of the filtered signal to use as a cancellation signal. This copying approach allows the system to generate the necessary interference cancellation signal without requiring additional expensive filter components, using instead relatively low-cost signal processing circuitry.
3Reliability
If multiple band-pass filters are used for each polarized signal path, then complete signal isolation is achieved, but device complexity increases
Solution Approach 1:
The patent merges the isolation functions of multiple filters into a single filter plus cancellation circuitry configuration. The analog interference cancellation mechanism combines the outputs of the single filter with phase-inverted delayed versions to achieve the isolation effect that would traditionally require multiple filters, thereby simplifying the overall device architecture.
Solution Approach 2:
The system uses feedback through the analog interference cancellation mechanism, where the filtered signal is delayed, phase-inverted, and fed back to cancel unwanted signal components. This feedback approach achieves complete signal isolation dynamically without requiring complex static filter configurations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables efficient separation of dual-polarized signals with reduced costs and space requirements, maintaining signal integrity and improving spectral efficiency in wireless communication systems.
Implementation Method 1
analog interference cancellation. A remaining BPF (or notch filter) derives one of the constituent polarized sub-signals from the dual-polarized signal. The derived constituent polarized sub-signal is sent to interference circuitry that delays the derived constituent polarized sub-signal out of phase (i.e., 180° out of phase) with its corresponding component in the dual-polarized signal. When the amplitude of the delayed constituent polarized sub-signal matches an amplitude (e.g., using an amplifier) of the original corresponding polarized sub-signal in the dual-polarized signal, summing the dual-polarized signal with the delayed constituent polarized sub-signal cancels out the delayed constituent polarized sub-signal in the dual-polarized signal.
Data Source
AI summary
Systems and methods for extracting polarized sub-signals from a dual-polarized signal includes isolating the polarized sub-signals using one or more filters. When a single filter is used to derive a first sub-signal, analog interference cancellation may be used to derive the second sub-signal. When two filters are used, the first and second sub-signals may each be derived using a corresponding filter.