What are the advantages and disadvantages of FIR and IIR filters?

 FIR (Finite Impulse Response) and IIR (Infinite Impulse Response) filters are the two main types of digital filters used in signal processing. Each has its advantages and disadvantages depending on the application.

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 FIR vs. IIR Filter Comparison

Feature	FIR Filters	IIR Filters
Impulse Response	Finite (settles to zero in finite time)	Infinite (theoretically never ends)
Stability	Always stable (if implemented correctly)	May become unstable due to feedback
Phase Response	Can be designed to have linear phase	Generally non-linear phase
Implementation Complexity	Requires more coefficients for sharp filters	Efficient with fewer coefficients
Design Flexibility	Easier to design with exact specifications	More difficult to design with precise specs
Computational Load	Higher (more multiplications/additions)	Lower (more efficient for real-time use)
Sensitivity to Quantization	Less sensitive	More sensitive (feedback path affected)
Applications	Audio, communications, systems needing linear phase	Control systems, real-time DSP, recursive filters

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 Advantages and  Disadvantages

FIR Filters

 Advantages:

• Always stable (no feedback loops)

• Can have exact linear phase

• Easier to implement on fixed-point processors (less risk of overflow)

• Better control over filter characteristics

 Disadvantages:

• Higher computational cost (especially for narrow-band filters)

• Needs longer filter length for sharp transitions

• Latency can be higher

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IIR Filters

 Advantages:

• More efficient (achieves desired response with fewer coefficients)

• Requires less memory and computation

• Good for real-time applications with tight constraints

 Disadvantages:

• Potential instability

• Usually have non-linear phase, which distorts signals

• More sensitive to rounding errors and quantization

• Harder to design and analyze

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 Which One Should You Use?

Scenario	Recommended Filter
Need linear phase (e.g., audio EQ)	FIR
Limited computational power	IIR
Safety-critical or stable system required	FIR
Real-time system needing sharp filtering	IIR
High precision/robustness against noise	FIR