Multistage Implementation of Digital Filters

Multistage Implementation of Digital Filters:

In some applications we want to design filters where the bandwidth is just a small fraction of the overall sampling rate. For example, suppose we want to design a lowpass filter with bandwidth of the order of a few hertz and a sampling frequency of the order of several kilohertz. This filter would require a very sharp transition region in the digital frequency a>, thus requiring a high-complexity filter.

Example :

As an example of application, suppose you want to design a Filter with the fallowing specifications:

Passband F_p = 450 Hz

Stopband F_s =500 Hz Sampling frequency F_s ~96 kHz

Notice that the stopband is several orders of magnitude smaller than the sampling frequency. This leads to a filter with a very short transition region of high complexity. In

Speech signals

1.   From prehistory to the new media of the future, speech has been and will be a primary form of communication between humans.

2.    Nevertheless, there often occur conditions under which we measure and then transform the speech to another form, speech signal, in order to enhance our ability to communicate.

3.  The speech signal is extended, through technological media such as telephony, movies, radio, television, and now Internet. This trend reflects the primacy of speech communication in human psychology.

4.  “Speech will become the next major trend in the personal computer market in the near future.”