author =   {Eric A. Lehmann},
  title =    {Real-Time Implementation of a Nearfield Broadband Acoustic Beamformer},
  school =   {Faculty of Engineering and Information Technology},
  address =  {The Australian National University, Canberra, ACT, Australia},
  month =    {November},
  year =     {2000},
  abstract = {The domain of array signal processing constitutes a field of study where many interesting and challenging projects can be undertaken. The work presented in this thesis is motivated by the implementation of a nearfield broadband beamformer using an array of acoustic sensors, which can be typically used for applications in speech acquisition. The objective of this work is to practically test this beamformer, and to create a fully integrated system that can be used to develop and implement similar designs. Based on theoretical principles, several software simulations performed with this type of array application have shown that it is possible to successfully implement the beamformer. However, several problems generally arise when considering a real-hardware realization of such a design, mainly related to the development of specific signal processing tasks. The work presented here aims to provide efficient solutions to these various problems. It focuses mainly on the design of the digital filters required for the beamformer, considering different aspects related to a specific implementation using digital signal processors. Different filter types and coefficient computation methods are considered for this implementation. The final design has to be furthermore developed in keeping with the different limitations implied by the hardware and software tools used to perform the digital processing of the sensor signals. An array consisting of 15 microphones and using an FIR filtering principle is then practically realized, and different experiments are finally performed in an anechoic environment with such a device. This thesis also presents some practical measurements obtained with this beamformer, which shows some promising results.}