OFDMA is a cellular air interface technology that uses orthogonal frequency division multiplexing to allow multiple users to access the network simultaneously over subsets of subcarriers. It provides superior air interfaces to CDMA and TDMA and is used in networks like WiMAX and LTE. OFDMA assigns subsets of subcarriers to individual users, whereas OFDM allocates users only in the time domain. OFDM uses a large number of subcarrier signals to carry parallel data streams.

1. OFDMA
• (Orthogonal Frequency Division Multiple
Access) A cellular air interface based on
OFDM for multiple, simultaneous users used
in communications networks such as WiMAX
and LTE, OFDMA provides air interfaces that
are superior to CDMA and TDMA.

2. What does Ofdma do?
• Orthogonal frequency-division multiple access
(OFDMA) is a multi-user version of the
popular orthogonal frequency-division
multiplexing (OFDM) digital modulation
scheme. Multiple access is achieved
in OFDMA by assigning subsets of subcarriers
to individual users.

3. What is the difference between OFDM
and Ofdma and what is in common?
• The main difference between an OFDM and
an OFDMA (Orthogonal Frequency Division
Multiple Access) system if the fact that in
the OFDM the user are allocated on the time
domain only while using an OFDMA system
the user would be allocated by both time and
frequency

4. What is OFDM and how it works?
• OFDM is a frequency-division multiplexing
(FDM) scheme used as a digital multi-carrier
modulation method. A large number of closely
spaced orthogonal sub-carrier signals are used
to carry data on several parallel data streams
or channels.

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