What is difference between OFDM and FDM

[moonnightingale]

What is difference between OFDM and FDM
Kindly explain in detail. i read both in wikipedia but unable to understand
And what is difference between Multiple access and Physical layer

 

[fabhat]

one is Frequency Division Multiplexing where your bandwith is divided in multiple subcarrier which are not overlapping with each other such as



Orthogonal frequency division multiplexing is a technioque which allow subcarrier to oveerlap and therefore, you can save bandwith but you will be more subject to intercarrier interference

 

[singh_prit]

in ofdm istead of taking different freq we take a single freq and its harmonics r used as other sub carriers this arrangement remove any overlap as crosscorelaion is zero so they become orthogonal to each other
if u want more info read ofdm tutorial on www.complextoreal.com