Digital Signal Processing Lab 6 Embedded DSP implementation

Digital Signal Processing Lab 6: Embedded DSP implementation of NLMS adaptive filter Toon van Waterschoot, Marc Moonen ESAT – Departement of Electrical Engineering KU Leuven, Belgium

Digital Signal Processing: Lab Sessions • Session 1: Signal generation & analysis in Matlab • Session 2: Embedded DSP implementation of energy-based voice • • • activity detector Session 3: Filter analysis & implementation in Matlab Session 4: Embedded DSP implementation of FIR filter Session 5: NLMS adaptive filtering in Matlab Session 6: Embedded DSP implementation of NLMS adaptive filter Session 7: Embedded DSP implementation of acoustic echo canceller 2 Image source: bigdata-madesimple. com

NLMS adaptive filtering in Matlab • Experiment 6. 1: Fixed-Point NLMS algorithm － － － Implement a fixed-point C algorithm in which the echo problem is simulated (i. e. convolving an input signal with the “true” echo path) and the NLMS algorithm is applied to recursively estimate an echo path model. Reuse as much code as possible from Lab Session 5, and exploit the concepts of circular buffering and double-length MAC registers for intermediate results. Test the algorithm in an environment similar to Experiment 3. 4 in Lab Session 5. Include an energy-based voice activity detector in the algorithm, which serves to freeze adaptation when the adaptive filter input signal energy falls below a threshold. 3