OFDM vs single-carrier

LTE uses OFDM as the basic signal format – OFDMA in the downlink and SC-FDMA in the uplink with various modulation formats. OFDM forms the basic signal format used within 4G LTE.

While these technologies are similar, there are key differences you should know: OFDMA allows multi-user access by subdividing a channel . MU-MIMO allows for multi-user access by using different spatial streams.

Following are the benefits or advantages of OFDMA: ➨Unlike OFDM which allocates all the subcarriers of the OFDM symbol to one user, OFDMA allocates subset of subcarriers to different users . Hence OFDMA makes efficient use of frequency allocations in comparison to FDMA and OFDM. ➨It provides multi-user diversity.