Introduction to OFDM
- Orthogonal frequency division multiplex
The principles of OFDM have been developed about 25 years ago however,
practical interest has only increased recently.
The main idea behind OFDM is to split the data stream to be transmitted into N parallel
streams of reduced data rate and to transmit each of them on a separate subcarrier. These carriers
are made orthogonal by appropriately choosing the frequency spacing between them. Therefore,
spectral overlapping among subcarriers is allowed, since the orthogonality will ensure that the
receiver can separate the OFDM subcarriers, and a better spectral efficiency can be achieved than
by using simple frequency division multiplex.