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EGEE 4110 Digital Signal Processing Lecture 4. Digital System Structures Professor Timothy Tuinstra. x 1 [n]. +. x 1 [n]+x 2 [n]. x 2 [n]. Basic DSP Building Blocks. x[n]. α x[n]. α. x[n]. x[n-1]. z -1. Basic DSP Building Blocks.
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EGEE 4110Digital Signal ProcessingLecture 4 Digital System Structures Professor Timothy Tuinstra
x1[n] + x1[n]+x2[n] x2[n] Basic DSP Building Blocks x[n] αx[n] α
x[n] x[n-1] z-1 Basic DSP Building Blocks Note: Delay blocks in DSP designs essentially imply a memory register large enough to hold one sample at whatever precision the architecture requires…i.e. a delay is a memory element!
g[n] h[n] h[n] g[n] Filter Interconnections • The associative property of convolution allows us flexibility when we create digital systems. =
The distributive property of convolution also allows us flexibility when we create digital systems. Filter Interconnections h[n] x[n] = h[n]+g[n] x[n] + g[n] x[n]
Filter Structures • Why do we care about filter structures? • Study of filter structures gives us important insights into hardware implementations. • Digital filters are straight-forward to implement on FPGA chips using VHDL, AHDL, or graphical interface • Study of filter structures gives us important insights into software implementations • C • Fortran
Structures for FIR filters • Recall the difference equation for an FIR: • This FIR requires M locations in memory
Structures for FIR filters x[n] b0 + z-1 b1 z-1 bM
Structure for IIR Filters (Systems) • Recall the general difference equation for IIR filters: IIR portion FIR portion
Structure for IIR Filters x[n] y[n] b0 + + z-1 -a1 b1 z-1 b2 -a2