Difference between SC-FDMA and OFDM
This page describes difference between SC-FDMA and OFDM modulation techniques.
SC-FDMA means Single Carrier Frequency Division Multiple Access and OFDM means Orthogonal Frequency Division Multiplexing.
As shown in the figure in SC-FDMA one extra module DFT is added before IFFT module in the transmitter chain and IDFT is added in the receiver chain. This converts OFDM chain into SC-FDMA chain. Without this two modules the chain is referred as OFDM transmit and receive chain.
SC-FDMA system usually will have low PAPR compare to OFDM system.
SC-FDMA system is less sensitive to frequency offset compare to OFDM system.
SC-FDMA is widely used in LTE subscriber terminals in the transmit path and its variant OFDMA is used in the eNodeB downlink(or receive path of LTE subscribers). While OFDM is used in many broadband technologies such as wimax-16d/16e, WLAN-11a/11n/11ac.
OFDM is referred as multicarrier modulation. It uses multiple rf carrier signals at different frequencies which sends some of the bits on each of the assigned channels. This seems to be similar to FDM but in the case of OFDM, total subcarriers are divided into subchannels and these subchannels are mapped to one single data/traffic source.
Merits of OFDM
SC-FDMA has merits as mentioned above.
OFDM also has many advantages compare to SC-FDMA.
• Frequency selective fading will be able to affect few of the subchannels/subcarriers and not entire band.
• OFDM overcomes effect of ISI occuring mostly in multipath channel environment.
SC-FDMA vs OFDMA, difference between SC-FDMA and OFDMA READ MORE
OFDM vs OFDMA,READ MORE.
OFDM Transmitter modules as per wimax standard, READ MORE.
OFDM Transmitter modules as per WLAN-11a standard, READ MORE.