What is OFDMA and how it works?
What is OFDMA and how it works?
OFDMA is a multi-user version of OFDM enabling concurrent AP communication (uplink & downlink) with multiple clients by assigning subsets of subcarriers, called Resource Units (RUs) to the individual clients. OFDMA allows multiple users with varying bandwidth needs to be served simultaneously.
What do you mean by OFDMA?
Orthogonal frequency-division multiple access
Orthogonal frequency-division multiple access (OFDMA) is a feature of Wi-Fi 6 (802.11ax) that allows access points to serve multiple clients at the same time. An example of how OFDMA works is when two phones send data over the same phone line.
How OFDM is better compare to FDM?
It is also the multiplexing technique which is used in analog system. In OFDM, Guard band is not required and the spectral efficiency of OFDM is high which oppose to the FDM….Orthogonal Frequency Division Multiplexing (OFDM):
| S.NO | FDM | OFDM |
|---|---|---|
| 7. | FDM supports low data rate. | While OFDM gives higher data rate. |
Why is OFDM important?
The main advantage of OFDM over single-carrier schemes is its ability to cope with severe channel conditions (for example, attenuation of high frequencies in a long copper wire, narrowband interference and frequency-selective fading due to multipath) without the need for complex equalization filters.
Where OFDMA differs than FDMA?
The most obvious difference between the two schemes is that OFDMA transmits the four QPSK data symbols in parallel, one per subcarrier, while SC-FDMA transmits the four QPSK data symbols in series at four times the rate, with each data symbol occupying a wider M x 15 kHz bandwidth.
Why does OFDM offers considerable advantage in terms of spectral efficiency compared with its multiplexing counterparts?
The fact that OFDM uses a large number of carriers, each carrying low bit rate data, means that it is very resilient to selective fading, interference, and multipath effects, as well providing a high degree of spectral efficiency.