EE-608 Course project Adaptive Echo Cancellation By LMS Algorithm

1. EE-608 Course projectAdaptive Echo Cancellation By LMS Algorithm Pannir Selvam E Vikram Mehta Praveen Goyal (05307810) Guided By Prof. U.B. Desai

2. AIM Echo Cancellation by minimizing the “ratio of mean square value of the residual echo to the variance of the echo signal” using Dual LMS algorithm. That is, to minimize R2(k) = σ2ε(k)/σ2u = E {[e(k)- e(k)]2}/ σ2u ^

3. Basic Configuration of an Echo-Canceller a(k) Source Adaptive Digital Filter Coeff. Vector Of Digital FIR Filter C(k) Impulse Response of Echo path G e(k) ^ (k) e - + + Trans Path ∑ ∑ Receiver + u(k) r(k)

4. Cascaded LMS Algorithm T e(k) = A (k) * G e(k) = A (k) * C(k) r(k) = u(k) + e(k) – e(k) r(k) = u(k) + A (k) * (G-C(k)) Where G is Echo Path vector with length N a(k) is transmitted Vector C(k) is coeff. Vector of the digital FIR filter u(k) is the received signal T ^ ^ T

5. References • “On the optimum size for the adaptive sign and LMS algorithms”. R.-Y. Chen and C.-L. Wang • “Dual LMS Algorithm for adaptive Echo Cancellation”, R.-Y. Chen and C.-L. Wang. • “Adaptive Noise Cancelling: Principles and Applications”, Bernard Widrow et al. IEEE, Vol. 63 No. 12 pp. 1692-1716 Dec 1975