Orthogonal Frequency Division Multiplexing (OFDM) is an efficient modulation format used in modern wireless communication systems including 5G. OFDM combines the benefits of Quadrature Amplitude Modulation (QAM) and Frequency Division Multiplexing (FDM) to produce a high-data-rate communication system .
Read moreWhat is OFDM symbol rate?
OFDM can generate a new symbol (composed of 48 subcarriers) every 4 microseconds . Based on that, it’s possible to signal 250,000 symbol transitions every second on each of the subcarriers.
Read moreWhat is OFDM symbol time?
802.11ax introduces a longer OFDM symbol time of 12.8 μs , which is four times longer than the legacy symbol time of 3.2 μs. Subcarrier spacing is equal to the reciprocal of the symbol time. As a result of the longer symbol time, the subcarrier size and spacing decreases from 312.5 KHz to 78.125 KHz.
Read moreHow is OFDM used?
Orthogonal frequency division multiplexing (OFDM) is a modulation technique that is used in several applications ranging from cellular systems (3GLTE, WiMAX), wireless local area networks (LANs), digital audio radio, underwater communications, and even optical light modulation .
Read moreWhich multiplexing technique is used in LTE?
LTE uses the popular orthogonal frequency division multiplex (OFDM) modulation scheme. It provides the essential spectral efficiency to achieve high data rates but also permits multiple users to share a common channel.
Read moreHow does OFDM transmit data?
In OFDM, multiple closely spaced orthogonal subcarrier signals with overlapping spectra are transmitted to carry data in parallel . Demodulation is based on fast Fourier transform algorithms.
Read moreWhy LTE uses OFDMA for downlink and SC-FDMA for uplink?
This is useful for LTE since it makes possible to exploit frequency dependence scheduling . For instance, it would be possible to exploit the fact that user 1 might have a better radio link quality on some specific bandwidth area of the available bandwidth.
Read more