25-06-2012, 06:02 PM
TIME-DELAY ESTIMATION AND ADPCM
TIME-DELAY ESTIMATION.pptx (Size: 1.24 MB / Downloads: 37)
Time-Delay Estimation
Our challenge is to estimate the time-delay between two signals.
Applications include radar, sonar, geophysics, biomedical, and audio.
Two measurements are made at sensors P1 and P2 separated by a distance d.
Angle of Arrival
where is the arrival of bearing angle to the source, and c is the propagationvelocity of the signal through the medium.
The estimation of the bearing angle is reduced to the estimation of the delay, D, given the noisy measurements x1(t) and x2(t).
Note that this approach can be extended to multiple dimensions using multiple sensors.
Summary
We demonstrated how to use an LMS filter to estimate the time delay (and source location) of a signal.
We discussed correlation and LMS approaches to this problem.
introduced adaptive differential pulse code modulation as an application of LMS filtering.
Briefly discussed an echo cancellation application.
Next: we will investigate new computational forms of the LMS filter (e.g., leaky gradient descent and lattice filters).