Lab 2: Theory 1.1 2006/07/26 10:55:47.264 GMT-5 2006/08/20 21:39:52.439 GMT-5 Thomas Shen tbshen@uiuc.edu Douglas L. Jones dl-jones@uiuc.edu Thomas Shen tbshen@uiuc.edu decimation downsample DSP interpolation multirate sampling multirate system sample-rate compressor sample-rate expander upsample A sample-rate compressor removes (D-1) of every D input samples. A sample-rate expander inserts (U-1) zeros after every input sample.

Introduction In the exercises that follow, you will explore some of the effects of multirate processing using the system in . The sample-rate compressor ( ↓ D ) in the block-diagram removes D 1 of every D input samples, while the sample-rate expander ( ↑ U ) inserts U 1 zeros after every input sample. With the compression and expansion factors set to the same value ( D U ), filters FIR 1 and FIR 3 operate at the sample rate F s , while filter FIR 2 operates at the lower rate of F s D .

Net multirate system

Later, you will implement the system and control the compression and expansion factors at runtime with an interface provided for you. You will be able to disable any or all of the filters to investigate multirate effects. What purpose do FIR 1 and FIR 3 serve, and what would happen in their absence?