Wireless Receiving Station MMSE Feedback for Overloaded MIMO
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Solution Overview
Problem
In overloaded MIMO systems, where the number of transmission stations exceeds the number of reception antennas, existing methods like MLD and spatial filtering face challenges, leading to increased demodulation errors due to uncancelable interference signals.
Innovation Solution
A wireless communication control method using MMSE weights to calculate and recalculate interference signal power, considering the power of uncancelable interference signals, to suppress interference and reduce demodulation errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of transmission stations exceeds the number of reception antennas (overloaded MIMO), then the system capacity and number of simultaneous transmissions are improved, but demodulation errors increase due to uncancelable interference signals
Solution Approach 1:
The patent changes the parameter of interference power estimation by iteratively recalculating interference power using updated MMSE weights. Instead of using fixed or initial interference power values, the system updates the interference power estimation based on newly calculated MMSE weights from previous iterations, thereby adapting to the actual interference conditions in overloaded MIMO scenarios and reducing demodulation errors
Solution Approach 2:
The patent implements a feedback mechanism where the calculated MMSE weights from one iteration are used to recalculate interference power, which then feeds back into the MMSE weight calculation for the next iteration. This iterative feedback loop allows the system to progressively refine both the interference power estimation and MMSE weights, improving demodulation accuracy while maintaining support for multiple simultaneous transmissions
2Reliability
If MLD or spatial filtering is used to suppress interference in overloaded MIMO, then demodulation errors are reduced, but computational complexity and processing overhead increase
Solution Approach 1:
Instead of implementing the full complexity of MLD which requires exhaustive search over all possible signal combinations, the patent applies a simplified iterative approach that performs partial interference cancellation. The system calculates MMSE weights and updates interference power estimates iteratively, achieving sufficient interference suppression without the excessive computational burden of complete MLD implementation
Solution Approach 2:
The patent performs preliminary calculation of MMSE weights using initial interference power estimates before actual signal demodulation. These pre-calculated weights are then used in the iterative refinement process, allowing the system to prepare interference suppression parameters in advance rather than computing them in real-time during signal processing, thereby reducing overall computational complexity
3Ease of operation
If conventional MMSE weight calculation is used without considering uncancelable interference, then computational simplicity is maintained, but interference suppression effectiveness is insufficient
Solution Approach 1:
The patent transforms the static MMSE weight calculation into a dynamic iterative process. Instead of calculating MMSE weights once based on fixed interference power assumptions, the system dynamically updates both the interference power estimates and MMSE weights through multiple iterations. This dynamic approach maintains computational simplicity at each iteration step while achieving progressively better interference suppression effectiveness
Data Source
AI summary
A wireless communication control method suppresses interference using an MMSE weight in an environment of wireless communication where the number of transmission stations transmitting a signal to a receiving station is larger than the number of reception antennas of the receiving station. The receiving station calculates power of an interference signal included in a signal received by the receiving station from the transmission stations the number of which is larger than the number of reception antennas, the interference signal corresponding to a part by which the number of transmission stations exceeds the number of reception antennas. The receiving station calculates the MMSE weight depending on the power of the interference signal, recalculates the power of the interference signal using the MMSE weight, and recalculates the MMSE weight depending on the recalculated power of the interference signal.