An improved TDOA-based location estimation algorithm for large aperture microphone arrays

Location estimation is a vital aspect of a real-time large aperture array system. To date, only time-difference-of-arrival (TDOA) based algorithms run sufficiently fast for a real-time system, so we have been using this kind of locator, LEMSalg, in our real-time environment. We present an improved location estimation algorithm. In the new method, microphone-pair selection is made dynamic, rather than fixed a priori. Dynamic selection requires derivation of parameters and criteria. Here we use theoretical analysis, real system statistics and experimental results to obtain: 1) a suitable range for microphone-pair separation; 2) an ideal length for the TDOA vector; 3) an effective TDOA quality assessment criterion. Experimental results based on real speech recorded in a moderately noisy environment at 5 different SNR levels are given to show the performance improvements.