Why SC-FDMA is used in the uplink LTE?
Single-carrier frequency division multiple access (SC-FDMA) is common choice for uplink of long term evolution (LTE) standard for broadband wireless communication. SC-FDMA is preferred for LTE uplink mainly due to its advantage of having low peak-to-average power ratio (PAPR) during signal transmission.
What is SC-FDMA in LTE?
SC-FDMA is a hybrid modulation scheme that combines the low peak-to-average ratio (PAR) of traditional single-carrier formats such as GSM with the multipath resistance and in-channel frequency scheduling flexibility of orthogonal frequency-division multiplexing (OFDM). Acronyms galore: LTE history and context.
What is the purpose of using SC-FDMA?
The main objective of SC-FDMA is to introduce transmission with lower PAPR than OFDMA.
Why LTE uses OFDMA for downlink and SC-FDMA for uplink?
In LTE, the OFDMA is used as downlink and SCFDMA as uplink modulation schemes; with OFDM as the basic building block. OFDMA is used for achieving high spectral efficiency in communication system; whereas, SC-FDMA for uplink multiple access scheme in LTE system.
What is OFDM and SC-FDMA 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).
How does SC-FDMA differ from OFDMA?
From the figure it is imperative that OFDMA is multi-carrier system with one data symbol carried over by one subcarrier; while SC-FDMA is a single carrier system where in each qpsk symbol is carried by one much wider bandwidth subcarrier.
What is uplink in LTE?
The actual implementation of the technology will be different between the downlink (i.e. from base station to mobile) and the uplink (i.e. mobile to the base station) as a result of the different requirements between the two directions and the equipment at either end.