1 / 18

An Overview of Delay-and-sum Beamforming

DSP Seminar (1 st semester, 2006 - 2007). An Overview of Delay-and-sum Beamforming. Outline. Objective Introduction Delay-and-sum Beamforming Future Works Q & A. Objective. Design a small-dimensional microphone array for beamforming in an acoustic environment with the presence of noises.

luann
Télécharger la présentation

An Overview of Delay-and-sum Beamforming

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DSP Seminar (1st semester, 2006 - 2007) An Overview of Delay-and-sum Beamforming

  2. Outline • Objective • Introduction • Delay-and-sum Beamforming • Future Works • Q & A

  3. Objective Design a small-dimensional microphone array for beamforming in an acoustic environment with the presence of noises

  4. Introduction (1) Microphone • Characterized by a spatial directivity pattern, which specifies the gain and phase shift that the microphone gives to a signal coming from a certain direction (angle-of-arrival)

  5. Introduction (2) Spatial directivity pattern • Function of angle-of-arrival and frequency • Transfer function for source of a particular frequency  at angle 

  6. Spatial filtering Introduction (3) Received signals from different microphones Filtering Summing “Virtual” spatial directivity pattern

  7. Introduction (4) Spatial filter design is based on two factors • Microphone characteristics • Microphone array configuration

  8. Introduction (5) Beamforming • Can be thought of as spatial filtering • Can increase the receiver sensitivity in the direction of wanted signals • Can decrease the receiver sensitivity in the direction of interferences and noises

  9. Covered in this seminar Introduction (6) Two categories of beamforming • Fixed beamforming • Delay-and-sum beamforming • Weighted-sum beamforming • Filter-and-sum beamforming • Adaptive beamforming • LCMV beamforming • Generalized sidelobe canceller

  10. Introduction (7) Basic differences between fixed and adaptive beamforming

  11. Introduction (8) Assumptions • Microphone gain = 1 at all angles for all frequencies • Far-field source (plane waveforms)

  12. Delay-and-sum Beamforming (1)

  13. Delay-and-sum Beamforming (2)

  14. Delay-and-sum Beamforming (3) Simulation settings • Number of microphones M = 5 • Distance between neighbouring microphones d = 0.03 m • Sampling frequency fs = 16 kHz • Source frequency f = 5000 Hz

  15. Delay-and-sum Beamforming (4)

  16. Future Works • Investigate into adaptive beamforming, e.g. GSC, which has the ability to minimize noises • Perform simulations to compare the performances of various existing types of adaptive beamforming in a noisy environment

  17. Reference Microphone Array Processing, Marc Moonen, Dept. E.E., EAST, K.U.Leuven

  18. Q & A Thank You!

More Related