What is MC?
MC (Multicarrier) is a signal transmission technique that splits data across multiple parallel narrowband carrier signals rather than transmitting on a single wideband carrier. Multicarrier modulation forms the basis of OFDM, the foundational waveform technology for 4G LTE and 5G NR. By dividing the available bandwidth into many narrow subcarriers, multicarrier systems achieve high spectral efficiency and robust performance in frequency-selective fading channels.
How Does MC Work?
In a multicarrier system, the input data stream is demultiplexed into N parallel sub-streams, each modulated onto a separate subcarrier at a different frequency. Because each subcarrier occupies only a narrow bandwidth, it experiences approximately flat fading — greatly simplifying equalization compared to wideband single-carrier systems. OFDM is the most common multicarrier implementation, using an IFFT to efficiently generate all subcarriers simultaneously. The subcarriers are spaced at 1/T (where T is the symbol duration), making them orthogonal. Multicarrier techniques offer inherent resistance to ISI, efficient use of fragmented spectrum, and easy adaptation to channel conditions through per-subcarrier power and modulation control.
Use Cases
5G NR air interface (CP-OFDM and DFT-s-OFDM), 4G LTE air interface (OFDMA), Wi-Fi (OFDM), digital broadcasting (DVB-T), and xDSL broadband (DMT).
3GPP / Standards Reference
3GPP TS 38.211 (NR physical channels — OFDM), IEEE 802.11 (Wi-Fi OFDM)
Related Terms
OFDM | CP-OFDM | SC | Carrier Aggregation | FBMC
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This glossary entry is part of the 5GWorldPro Complete 5G Glossary. To go deeper into 5G architecture and technology, explore our 5G Training courses.
