Why SC-FDMA is used in LTE?
Why SC-FDMA is used in LTE?
SC-FDMA is preferred for LTE uplink mainly due to its advantage of having low peak-to-average power ratio (PAPR) during signal transmission. The performance of SC-FDMA depends on modulation scheme used for it.
What is SC-FDMA and how is it different from OFDM?
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 does SC-FDMA stand for?
Single Carrier Frequency Division Multiple Access
Single Carrier Frequency Division Multiple Access (SC-FDMA) is a promising technique for high data rate uplink communication and has been adopted by 3GPP for it next generation cellular system, called Long-Term Evolution (LTE). SC-FDMA is a modified form of OFDM with similar throughput performance and complexity.
What is the advantage of SC-FDMA?
SC- FDMA has a lower PAPR and lower sensitivity to carrier frequency errors while OFDMA provides better frequency diversity resulting in better immunity against multipath fading.
What is the advantage of SC-FDMA over OFDM?
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.
Why are there 12 subcarriers in LTE?
In the downlink, the subcarriers are split into resource blocks. This enables the system to be able to compartmentalise the data across standard numbers of subcarriers. Resource blocks comprise 12 subcarriers, regardless of the overall LTE signal bandwidth. They also cover one slot in the time frame.
What modulation does LTE use?
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.
What is the difference between single-carrier and multicarrier modulation?
Single-carrier modulation systems exploit only one signal frequency to transmit data symbols. Differently, multicarrier modulation systems divide the whole frequency channel into many subcarriers and the high-rate data stream is divided into many low-rate ones transmitted in parallel on subcarriers.
What 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).
Which multiple access is used in LTE?
OFDMA – The default multiple access value for LTE Downlink is OFDMA.
What is PHY layer in LTE?
This paper focuses on the LTE physical layer (PHY). The LTE PHY is a highly efficient means of conveying both data and control information between an enhanced base station (eNodeB) and mobile user equipment (UE). The LTE PHY employs some advanced technologies that are new to cellular applications.