To overcome the effect of multi path fading problem available in UMTS, LTE uses Orthogonal Frequency Division Multiplexing (OFDM) for the downlink – that is, from the base station to the terminal to transmit the data over many narrow band careers of 180 KHz each instead of spreading one signal over the complete 5MHz …
Read moreWhat is the difference between OFDM and SC-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.
Read moreWhat is DFT spread OFDM?
The DFT-spread OFDM is a form of single-carrier technique that possesses almost all advantages of the multicarrier OFDM technique (such as high spectral efficiency, flexible bandwidth allocation, low sampling rate, and low-complexity equalization).
Read moreWhat is the advantage of single carrier FDMA comparing to OFDMA?
Owing to its inherent single carrier structure, a prominent advantage of SC-FDMA over OFDM and OFDMA is that its transmit signal has a lower peak-to-average power ratio (PAPR) , resulting in relaxed design parameters in the transmit path of a subscriber unit.
Read moreHow OFDM is used in LTE?
LTE uses a pre-coded version of OFDM called Single Carrier Frequency Division Multiple Access (SC-FDMA) in the uplink . This is to compensate for a drawback with normal OFDM, which has a very high Peak to Average Power Ratio (PAPR).
Read moreWhat is OFDM symbol in LTE?
One of the key elements of LTE is the use of OFDM (Orthogonal Frequency Division Multiplex ) as the signal bearer, as well as OFDM’s associated access schemes, OFDMA (Orthogonal Frequency Division Multiple Access) and SC-FDMA (Single Carrier Frequency Division Multiple Access).
Read moreWhat is modulation in mobile networks?
Modulation is a process of mixing signals with a sinusoid to produce a new form of signals . The newly produced signal has certain benefits over an un-modulated signal. Mixing of low-frequency signal with a high-frequency carrier signal is called Modulation.
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