Digital Filter Design

Background Research-

Part One: Literature Review. Review the lecture notes and other sources of information, detailing different aspects of FIR filter design. Obtain, read and familiarise yourself with various review and journal articles, books, Internet sites and manufacturers information on all aspects of digital based filters.

Practical Activities-

Part Two: FIR Filter Design. Using the appropriate design equations design your own set of FIR filter co-efficients in order to fulfil the given design criteria. You need to demonstrate for the first two iterations, by hand, the calculation of the coefficients. Obviously, this can be a rather repetitive process and if you are not extremely careful you will make mistakes. It is recommended (essential) that you write a small program to calculate the co-efficients for you - i.e. write a MATLAB based program to design your filter. Once the programme is working check that the hand calculated coefficients much the one obtained using the Matlab program for the first two iterations.

Part Three: Design Verification. Make use of MATLAB's SPTOOL to verify your design. Print graphical plots of the impulse response, any window functions used and the final filter response. Note that although you may use SPTOOL to verify your design, you must write your own small design program to calculate the filter.

Part Four: Filter Simulation. Import your filter design into SPTOOL and using a suitable test signal file, verify that your filter works correctly.

Presentation of results & Write up-

Part Five: During the assignment period you should present your FIR filter design to the subject tutor - i.e. using MATLAB demo your calculation software.

Part Six: You will write a detailed technical report of approx. 2000 words long plus diagrams, charts and programs- the content of which will be as detailed below. You should bring together relevant information obtained through the research periods of the assignment, collate results from your practical activities and present your findings in a clearly written analytical report. The report will demonstrate that you have undertaken an extensive level of research activity and that you have understood the subject matter to an appropriate level.

Project details: Name of the project, Course title, Module title, Filter specification parameters (given individually), Year written, Your name.

General review of FIR design method used: An explanation of how you designed the FIR filter, the methods, processes and equations used. If you decided to write a program to help calculate the filter co-efficients discuss the use of this program here include a copy of your co-efficient calculator program along with a co-efficient data table in the appendices at the end of the report.

Comments and Conclusions: General review of the whole process, the success of the project, final conclusions.

Digital Signal Processing-

What you need to do:

Step One: For the design specifications of your filter, see the excel file for specifications (UDO). You need to demonstrate for the first two iterations( n=0 & n=1), by hand, the calculation of the coefficients.

Step Two: Develop a Matlab program to calculate the rest of the coefficients,

Step Three: Once your filter programme is working, this needs to be demonstrated to the tutor in charge of the session.

Step Four: From your frequency response of the filter you need to corroborate or otherwise that your filter satisfies the design criteria, for example Transition width, Stop band/Pass band attenuations, cut off frequencies, etc...

Step Five: Assuming your filter design is successful, you need to proceed to verify your design by proceeding to SPTOOL. You need to export your filter from Matlab. DO NOT design the filter again in the SPTOOL.

Step six: On completion of SPTOOL verification, proceed to writing up your report as specified in assignment brief,

Design specification:

Fist design - High Pass, Sampling:16kHz, Cutoff: 7k, Df: 800Hz, Ripple <0.05dB, Max stop Band attenuation

Second Design- Band Pass, Sampling:32kHz, Lower Cutoff: 2k500, Pass band width: 3kHz, Df: 2k, Stop Band attenuation:-better than 57dB.