Abstract
Digital filter is a part of digital transmission system of modulation and demodulation, include FIR digital filter and IIR digital filter, digital filter design ideas are digital filter translate into analog filter.
Firstly, this text gave the parameter, compared FIR digital filter and IIR digital filter’s designing ways, adopted MATBLE software to write programs, designed band pass and low pass filters, acrossed designing results, explained those ways’ advantage and disadvantage. By an example, watched the results.
Secondly, when the parameters are unchangeable , MATLAB signal disposal toolbox FDAtool to designed band pass and low pass filters,gave detailed processes.
Lastly, this text designed digital modulation and demodulation-2ASK in modern communication ,add designed filters.used smulink software to simulate , got the results in 2ASK system, in order to validate filter’s capabilities. In the end summarized the design.
Key words: MATLAB software 、FIR digital filter、 IIR digital filter、Smulink