Skip to main content

This is a closer view of Figure 2.20 part B. There is a horizontal frequency axis marked with four equally spaced markers labelled ‘subcarrier frequencies’. Centred on each frequency is a wave shape with a high positive peak centred on the marked frequency, falling away sharply on either side in ripples of decreasing amplitude. Because the frequency markers are close together, there is a lot of overlap of the wave shapes, so that as the wave shape falls away on either side of the peak, at a value of about three-quarters of its peak value it intersects the wave shape centred on the adjacent subcarrier frequency. Each subcarrier peak coincides with zeros on all the other waveforms it overlaps with.

 4.2 Orthogonal frequency division multiplexing (OFDM)