Research On Methods Of Sound Source Localization In The Circular Harmonic Domain Using A Pseudointensity Vector

The technology of sound source localization with microphone array has been a hot research topic in speech signal processing.However,the performance of classical sound source localization methods in the array element domain will be worse with the deterioration of noise and reverberation.The accuracy can not meet our demand in practical application,and the time complexity of the algorithm is high,which is not conducive to real-time implementation.Therefore,it is a key problem to be solved in the field of microphone array processing to effectively realize the sound source localization in reverberation and noise environment.With the continuous development of the theory of harmonic domain,sound source localization methods in the circular harmonic domain provide an important technical way to effectively realize the sound source localization in reverberation and noise environment,which localization method using the pseudointensity vector is the main representative among.In order to estimate the exact direction of the sound source,we take the microphone array as research object and localization method using the pseudointensity vector as main basic approach,discuss in one aspect from single sound source.Specific work in this paper is as follows:First of all,the basic theory of circular harmonic analysis of microphone array is introduced.And then,the basic principle of classical source local method(SRP)is described in detail.At the same time,the performance simulation analysis is carried on.The results show that the localization accuracy of the sound source localization method based on steered response power in the circular harmonic domain is not high.And,the localization performance is easily affected by noise and reverberation.In order to overcome the defect that the performance of the sound source localization method based on steered response power in the circular harmonic domain is deteriorated in low SNR and high reverberation environment,this paper applies the sound source localization method using the pseudointensity vector to circular harmonic domain and proposes the localization method using the pseudointensity vector in the circular harmonic domain.The simulation result shows that this method can improve the overall localization performance compared with the method based on steered response power in the circular harmonic domain,and the difference of the azimuth localization performance is reduced,but the effect is not obvious in low SNR and high reverberation environment.In order to improve the poor performance of the sound source localization method using the pseudointensity vector,the improved method based on the phase transform is proposed.In the specific PHAT weighting process,there are two kinds of weighting methods: one is the PHAT weighting of the sound pressure signal in the array element domain,and the other is the PHAT weighting of the eigenbeam in the circular domain.The simulation result shows that the performance of the former is better than the latter.The localization accuracy of the method is improved from the perspective of time-frequency domain.In addition,the beam pointing weighting method is proposed from the perspective of spatial domain.Preliminary result shows that this method improves the sound source localization performance effectively.Finally,combining the method in time-frequency domain and spatial domain,we propose another method based on time-frequency domain and spatial domain joint processing.Simulation analysis and actual measurement data show that this method is superior to the method improvevd only in time-frequency domain or spatial domain.