Adaptive Array Beamforming Using Stored Noise Correlation Matrices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
MVDR beamforming experiences a decrease in communication quality due to errors in the steering vector, and while it is more robust than MPDR, it reduces communication throughput as it requires a time period without desired wave reception to calculate the interference noise correlation matrix.
Innovation Solution
An adaptive control device calculates a correlation matrix for each time slot and stores it, using a previously calculated matrix as an interference noise correlation matrix when the desired wave is received, allowing for the calculation of weighting factors using its inverse matrix to perform beamforming without reducing throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MVDR beamforming is used to improve robustness against steering vector errors, then communication quality is maintained, but communication throughput decreases due to requiring time periods without desired wave reception for interference noise correlation matrix calculation
Solution Approach 1:
The patent calculates and stores interference noise correlation matrices in advance during time slots when desired waves are not received. These pre-calculated matrices are then reused in subsequent time slots when desired waves are received, eliminating the need to pause communication for matrix calculation and thereby maintaining communication throughput while ensuring communication quality through robust MVDR beamforming
Solution Approach 2:
The patent discards the requirement to calculate interference noise correlation matrices during desired wave reception time slots by recovering and reusing previously calculated matrices from other time slots. This approach recovers the lost communication throughput while maintaining the reliability benefits of accurate interference noise characterization
2Reliability
If time periods without desired wave reception are provided to calculate interference noise correlation matrix, then robustness against steering vector errors is improved, but communication throughput is reduced
Solution Approach 1:
The interference noise correlation matrices are calculated in advance during time slots allocated for interference measurement, storing the results for future use. This preliminary action ensures that accurate interference noise characteristics are available when needed without causing time loss during desired wave reception periods
Solution Approach 2:
The patent implements periodic calculation of interference noise correlation matrices during specific time slots in a cyclic manner, while using pre-calculated matrices during other periods. This periodic approach balances the need for accurate interference noise characterization with the need to maximize communication throughput during desired wave reception
Data Source
AI summary
An adaptive array antenna system receives a desired wave arriving through K time slots each allocated to one of K transmitting stations. In the adaptive array antenna system, an adaptive control device includes a correlation matrix calculating unit, a correlation matrix storing unit, an inverse matrix calculating unit, and a weighting factor calculating unit. The inverse matrix calculating unit acquires a correlation matrix having been calculated at previous time for another time slot other than the current time slot from the correlation matrix storing unit, regards the acquired correlation matrix as an interference noise correlation matrix, and calculates an inverse matrix of the interference noise correlation matrix. The weighting factor calculating unit calculates values of a plurality of weighting factors used by a beamforming unit using the inverse matrix.