Microphone Array System With Rotational Symmetry For Multi-Speaker Sound Acquisition
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Solution Overview
Problem
Microphone array systems face challenges in effectively acquiring sound from multiple speakers in a reception space due to sound propagation losses and limitations in directivity patterns, particularly when speakers are seated around a table, as existing systems are primarily designed for single-user applications and struggle with symmetry and directivity outside their plane.
Innovation Solution
A microphone array system with N-fold rotational symmetry about a vertical axis, featuring seven microphone transducers arranged on a hexagonal pyramid, uses beamformer weights to form beamformer signals for multiple spatial reception sectors, allowing for efficient sound source location and filtering, and includes a post-filter module to enhance speech acquisition by attenuating noise and adjusting sound output volumes independently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If linear or planar microphone array geometries are used for single-user applications, then sound acquisition from a single user is enhanced, but the system struggles with sound propagation losses and directivity limitations when multiple speakers are seated around a table
Solution Approach 1:
The patent transitions from symmetric linear/planar arrays to an asymmetric 3D distributed array geometry. Seven microphones are positioned at non-coplanar coordinates (including vertical elevation differences), creating an asymmetric spatial configuration that provides omnidirectional coverage and resolves the directivity limitations of traditional symmetric arrays when speakers are distributed around a table.
Solution Approach 2:
The patent adds the vertical dimension (elevation) to the traditional horizontal plane array configuration. By positioning microphones at different heights (e.g., z-coordinates of 0.05m, 0.15m, 0.25m), the system creates a three-dimensional spatial arrangement that enables effective sound acquisition from multiple users seated around a table, overcoming the planar geometry limitations.
2Reliability
If beamforming techniques are applied to favor sound reception from selected locations, then sound propagation losses are reduced, but processing time increases when multiple sound sources are present
Solution Approach 1:
The patent pre-calculates and stores beamformer weight matrices for multiple predefined spatial directions before actual sound acquisition. When multiple speakers are present, the system can immediately apply the appropriate pre-computed weights without performing real-time optimization, significantly reducing processing time while maintaining beamforming's sound enhancement benefits.
Solution Approach 2:
The patent dynamically adjusts beamforming parameters (weight matrices) based on detected sound source locations and characteristics. By changing the spatial parameters and weighting factors according to the actual distribution of speakers around the table, the system optimizes sound reception quality for the current configuration while managing computational complexity.
3Measurement precision
If microphone arrays are designed for single-user applications, then directivity patterns are optimized for one location, but the system fails to provide adequate coverage and symmetry for multiple users seated around a table
Solution Approach 1:
The patent designs a universal microphone array configuration that serves multiple functions: it can simultaneously capture sound from any user seated at any position around the table with equal effectiveness. The seven-microphone 3D arrangement provides symmetric omnidirectional coverage, making the system adaptable to any speaker configuration without requiring reconfiguration, thus achieving both precision and versatility.
Data Source
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AI summary
To obtain a method of positioning a wireless terminal capable of obtaining the position of each communication terminal by measuring distances with installed communication terminals each other without fixedly installing a base station. A positioning management terminal 100 includes a positioning object decision section 130 that selects a terminal to be positioned, which is a positioning object, and a positioning standard terminal, whose position is known, among the wireless terminals 200; a positioning management section 120 that requires distance information between the terminal to be positioned and the positioning standard terminal; and a position calculation section 140 that calculates the position of the terminal to be positioned.; The positioning management section 120 requires distance information from the positioning standard terminal selected by the positioning object decision section 130 to the terminal to be positioned selected by the positioning object decision section 130. The position calculation section 140 calculates the position of the terminal to be positioned using the distance information and position information of the positioning standard terminal.