Overview
Frequency domain based beamformer
Discussion
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THIS MODULE IS DEPRECATED AND NOT RECOMMENDED FOR NEW DESIGNS. PLEASE USE THE SbBeamformerV2 MODULE INSTEAD. |
This module implements a frequency domain based beamformer. The module has a multichannel input pin "in" which correspond to N microphone signals. The microphone signals must already be in the frequency domain (e.g., after an FFT or WOLA filterbank). The module has an internal table of complex filter coefficients of size [numMics, numBins]. The module multiples each microphone signal by complex coefficients and then sums across all microphone channels. This corresponds to filtering each microphone signal and summing the results.
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The coefficients are ordered as follows. The first 2 * numBins * numMics coefficients correspond to the first beamformer. The coefficient are ordered first based on input channel and then on frequency bin. The coefficient are interleaved real / imag values. The beamformer coefficients can be loaded using the function sb_beamformer_config.m
Type Definition
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typedef struct _ModuleSbBeamformer
{
ModuleInstanceDescriptor instance; // Common Audio Weaver module instance structure
INT32 numBeams; // Number of beams allocated.
INT32 numCoeffs; // Number of coefficients to allocate
FLOAT32* coeffs; // Complex beamformer coefficients.
} ModuleSbBeamformerClass; |
Variables
Properties
Name | Type | Usage | isHidden | Default value | Range | Units |
numBeams | int | const | 1 | 1 | Unrestricted | |
numCoeffs | int | const | 1 | 132 | Unrestricted | |
coeffs | float* | parameter | 0 | [2 x 33] | Unrestricted |
Pins
Input Pins
Name: index
Description: Selects beam
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Sample rate range: Unrestricted
Complex support: Complex
Output Pins
Name: out
Description: Beam output
Data type: float
MATLAB Usage
File Name: sb_beamformer_module.m
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