Geetha Shishu Shikshana Sangha (R)

GSSS INSTITUTE OF ENGINEERING & TECHNOLOGY FOR WOMENDEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING

TITLE

Presented by

SHRUTHI C N 4GW12EC418

ANUSHA G 4GW13EC401

ARCHANA M 4GW13EC402

SHRUTHI K S 4GW13EC426

Under the Guidance of

ARAVIND.RAssistant Professor

Dept. of ECE, GSSSIETW

19/23/2015

INTRODUCTIONINTRODUCTION

FIR FILTER DESIGN

1. Filter specification

2. Filter coefficient calculation

3. Realization

4. Analysis of finite word length effects

5. Implementation

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LITERATURE SURVEYLITERATURE SURVEYRuan A W,Li ,J.X, proposed and presented an ALU based

universal FIR filter where various FIR filters can be implemented just by programming instructions in the ROM with the identical hardware architecture.

The presented ALU based universal FIR filter suitable for implementation in FPGA is proposed in this paper.

Multiplexer and accumulator based architecture used in conventional FIR the proposed ALU architecture implements FIR functions using accumulator and shift registers controlled by the instructions of ROM.

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OBJECTIVESOBJECTIVES

1. To study the different methods of calculating filters coefficients.

2. To study various FIR filter structures used for implementing the filters.

3. To design and implement FIR low pass filter on FPGA.

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METHODOLOGYMETHODOLOGY

1. Windowing method : Windowing method is much easier to implement , It is a straightforward approach.

2. Frequency sampling method:

The frequency sampling method allows us to design non recursive FIR filter for both standard frequency filters (low pass, high pass & band pass filter).

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FIR filter design procedure:

1. Select a suitable window function

2. Specify an ideal response .

3. Compute the coefficients of the ideal filter .

4. Multiply the ideal coefficients by the window function to give the filter coefficients

5. Evaluate the frequency response of the resulting filter and iterate if necessary (typically, it means increase M if the constraints you have been given have not been satisfied).

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Proprieties of window method:Proprieties of window method: 1. Equal transition bandwidth on both sides of the ideal

cutoff frequency.

2. Equal peak approximation error in the pass-band and stop band.

3. Distance between approximation error peaks is

approximately equal to the width of the window main-lobe.

4. The width of the main-lobe is wider than the transition band.

5. Peak approximation error is determined by the window shape , independent of the filter order.

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RESULTS TILL DATERESULTS TILL DATE

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EXPECTED END RESULTSEXPECTED END RESULTS

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CONCLUSIONCONCLUSIONThe FIR filters are widely used in digital signal

processing and can be implemented using programmable digital processors. But in the realization of large order filters the speed, cost,and flexibility is affected because of complex computations.

So, the implementation of FIR filters on FPGAs is the need of the day because FPGAs can give enhanced speed.

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