# Transforms: Part 5 - OFDM

Thus far we have looked at transforms from a somewhat abstract viewpoint. In contrast, here we look at an application where transforms take center stage.

Fig. 1 - Transform duality in action. In the time domain, the impulses from individual samples are orthogonal so that perfect reconstruction of the waveform is possible. In the frequency domain, the same orthogonality eliminates crosstalk between the frequency bands. The DFT allows those frequency bands to be separated.

Fig.2 - When guard intervals are used, transmission rate is slowed down so that every symbol is longer. That means the receiver useful time, Tu, can better avoid reflections of an earlier symbol encroaching on the beginning of the symbol time Ts.

# Transforms: Part 7 - Standards Conversion

The transform is a useful device that has some interesting characteristics. On one side of a transform we might have the spatial domain, for example data describing an image in terms of brightness as a function of position. On the…

# Master Control: Part 1 - The Four Missions Of Master Control

We begin this mini series with some history, the basic principles of Master Control and the evolution of centralcasting.

# Vendor Spotlight: Telestream

Telestream, based in Nevada City, Calif. (with additional offices in Westwood, Mass,), is a privately held company that supports customers around the world in the Broadcast, Professional Video Production, Education, Corporate and Military market segments. The company is celebrating its 2…

# Transforms: Part 6 - The Discrete Cosine Transform (DCT)

The Fourier Transform is complex in the mathematical sense, which means that each coefficient is represented by complex number.

# Transforms: Part 4 - Discrete Fourier Transforms

As we saw earlier when discussing transform duality, when something happens on one side of a transform, we can predict through duality what to expect on the other side.