Digital Speaker Array Beamforming With Channel Equalization
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Solution Overview
Problem
Digital speaker array systems face challenges in channel equalization and beam controlling, particularly in reverberant environments, due to nonlinear distortion and low over-sampling rates, which result in frequency response fluctuations and poor beam steering capabilities, limiting their ability to reproduce the original sound field and generate multiple directional beams.
Innovation Solution
A method and device for channel equalization and beam controlling in digital speaker array systems, involving digital format conversion, channel equalization, multi-bit Σ-Δ modulation, thermometer code conversion, dynamic mismatch-shaping processing, and channel information extraction to regulate both magnitude and phase of transmission signals, ensuring frequency response flatness and improved beam directivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If multi-bit Σ-Δ modulation and dynamic mismatch shaping technique are used to eliminate high-order harmonic components, then total harmonic distortion ratio is reduced, but frequency response fluctuation in audio band of each channel remains uncorrected, causing great deviation between system restoration signal spectrum and sound source signal real spectrum
Solution Approach 1:
The patent segments the signal processing into distinct stages: first applying multi-bit Σ-Δ modulation to reduce harmonic distortion, then applying channel equalization to correct frequency response fluctuations. This segmentation allows each processing stage to address specific issues independently and effectively.
Solution Approach 2:
The patent applies channel equalization as a preliminary action before dynamic mismatch shaping. By pre-equalizing the frequency response of each channel, the system prepares the signal in advance to prevent frequency response fluctuations from causing spectral deviation, thereby improving the effectiveness of subsequent processing stages.
2Ease of operation
If channel delay regulation is used for beam-forming, then beam steering is achieved in free field environment, but beam directional control fails in reverberant environment with multi-path scattering signals
Solution Approach 1:
The patent transitions from static delay regulation to dynamic adaptive beam-forming. The system continuously adapts to environmental conditions by using self-adaptive algorithms that adjust beam-forming parameters in real-time, enabling reliable beam directional control in both free field and reverberant environments with multi-path scattering.
Solution Approach 2:
The patent implements feedback mechanisms where the system monitors the acoustic environment and adjusts beam-forming parameters accordingly. This feedback enables the system to compensate for multi-path scattering effects and maintain stable beam directional control in reverberant environments, significantly improving reliability compared to simple delay regulation.
3Device complexity
If simple channel delay control method is used for beam-forming, then implementation is simple, but beam control ability is weak and cannot accomplish steering control of multiple beams
Solution Approach 1:
The patent implements a universal beam-forming framework that can perform multiple functions: single beam steering, multiple simultaneous beam steering, and adaptive beam-forming. The self-adaptive array beam-forming algorithm provides a multi-functional solution that handles various beam control requirements, significantly enhancing versatility while maintaining reasonable implementation complexity through modular architecture.
Data Source
AI summary
A method and device of channel equalization and beam controlling for a digital speaker array system includes (1) converting digital format; (2) performing channel equalization; (3) controlling beam-forming; (4) performing multi-bit Σ-Δ modulation; (5) performing thermometer code conversion; (6) performing dynamic mismatch-shaping processing; and (7) extracting the channel information to send to the digital power amplifier and drive the array sound. A device includes a sound source, a digital converter, a channel equalizer, a beam-former, a Σ-Δ modulator, a thermometer coder, a dynamic mismatch shaper, an extraction selector, a multi-channel digital power amplifier and a speaker array. Each unit connects to each other serially.