# Conclusion

In this course you have learned about discrete-time signals and the discrete-time systems that use them. In doing so, you have focused on digital filtering and found out why advances in digital computer processing have allowed digital filtering to be used in scenarios where analogue filters would once have been the only viable solution. You have seen how relatively simple averaging filters can remove high-frequency noise, and also that more complex filters are designed.

This completes your study. You should now be able to:

- understand how filtering of discrete-time signals can be achieved by mathematical processes such as averaging
- understand how mathematical operations applied to a discrete-time signal in the time domain can result in the removal or reduction of unwanted aspects of the signal
- explain why filters are designed in the frequency domain, and specify a digital filter to achieve a desired filtering effect.

This OpenLearn course is an adapted extract from the Open University course T312 Electronics: signal processing, control and communications

OpenLearn - Electronic applications
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