ibm - cvut student research projects implementation of microphone arrays on cell broadband engine...

IBM - CVUT Student Research Projects

Implementation of microphone arrays on

Cell Broadband EngineJosef Urban (urbanj2@fel.cvut.cz)Antonin Kadlec (kadlea1@fel.cvut.cz)

IBM - CVUT Student Research Projects

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Motivation

Microphone Array

for each: stream,

microphone positionYou are here!

• source location ( LEFT/RIGHT, 1D, 2D, 3D ... )

• examples of using :

- intelligent camera system

- extracting a sound from certain

- direction, watching of moving fish swarm ...

IBM - CVUT Student Research Projects

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Basic Element

• time delay of arrival - tdoa

FFTstream1

FFTstream2 Conjugate

transpose

IFFT MAX? tdoa

• block samples 512, 1024 .. 2^n

• tdoa counted for each pair of streams

• CSPS (CrossPowerSPectrum) -> tdoa

• overlapping, hamming window

IBM - CVUT Student Research Projects

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What we have implemented

• tdoa computed on 4 SPUchannel1 buffer

channel2 buffer

results - tdoa

SPU2SPU1 SPU3SPU3

DMA

DMA • CELLied tdoa function

• optimized vector operations

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Current Functionality, Testing

• from the CPSP function we got maximum value and its position -> TDOA estimate

• program was tested on two identical streams (text files with samples) simulating one microphone pair

• we couldn’t verify 100% functionality but the results are supposed

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Further work

• optimizing for n>2 streams • computing models for location in different

areas ( open area, room ) – for accurately locate, we need to consider reflections, room geometry

• take as a sources of streams soundcards and process location in a real time

IBM - CVUT Student Research Projects

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Q&A