Difference between OFDM and OFDMA

In OFDM systems, only single user can transmit on all of the sun carrier at any given time. OFDMA is allows multiple user to transmit simultaneously on the different sub carrier per OFDM symbol. So here this article gives the main key difference between OFDM ad OFDMA to better understand this topic.

What is OFDM?

OFDM is a multi-carrier transmission technology. Orthogonal frequency division multiple access (OFDM) is  basically used to obtain a higher data rate in the multipath fading environment of mobile communication. Only single user can transmit on all of the sub carrier at any give time. 

What is OFDMA?

OFDMA is employed in mobile Wi Max system deployed around the world. It also employed in LTE system beings deployed, total sub carrier are permuted and assigned to sub channel. Hence many Sss can occupy the same sub channel but use different sub carrier to transmit the information.

Difference between OFDM and OFDMA:

  • OFDM stand for orthogonal frequency division multiplexing, while OFDMA stand for orthogonal frequency  division multiple access.
  • OFDM is a less robust to fading as well as interference, OFDMA is more robust to fading as well as inference compare to OFDM.
  • OFDM is fixed Wi max PHY, OFDMA is mobile Wi max phy.