Audio and Data Signals

Innovative Technologies in Education (ITE)

The Audio and Data module deals with the characteristics of audio and data information signals. Subjects such as time dependence and spectrum are discussed and examined using this module.
Speech and music signals, generated by a microphone supply the real world signals to be tested. Distortion effects and the logarithmic behaviour of the ear are studied and tested.

Data signals such as RZ/NRZ. multilevel PAM, Manchester code and Miller code are generated and studied.

A data interface service unit to display audio and data signals in time and frequency domains on the student's personal computer should support the training module.

The training module consists of a 5 element graphic equalizer, a variable distortion circuit, linear and logarithmic potentiometers, a 600-9600 bits per second bit rate generator, unipolar and bipolar RZ/NRZ coder, 4-8 level PAM generator, a Manchester coder and a 4 state miller coder.

EXPERIMENTS LIST

1. Signals and Systems - periodic, stochastic and deterministic signals - power spectral distribution - effect of bandwidth - pseudo-random noise 2. The Voice Signal - time domain characteristics - frequency spectrum - quality and intelligibility - characteristics of the ear - non-linear distortion effects 3. Baseband Data - RZ and NRZ codes - Multilevel PAM - Manchester code - Miller code

TECHNICAL SPECIFICATIONS

The audio and Data Module should contain the following main blocks:

- RZ/NRZ Coder - Multilevel Pam - Bit Rate Generator - Manchester Coder - Miller Coder - Non-linear Distortion Coder - Graphic Equalizer