LTE SC-FDMA and LTE Uplink LTE (Long-Term Evolution) utilizes a specific modulation scheme for the uplink known as Single-Carrier Frequency Division Multiple Access (SC-FDMA). SC-FDMA is a modulation and access scheme that provides advantages for uplink transmission in LTE networks. Introduction to SC-FDMA and uplink frame structure Marriage of single carrier transmission and FDMA Uplink … Read more
LTE Parameters and Downlink Modulation LTE (Long-Term Evolution) utilizes various parameters and downlink modulation schemes to optimize data transmission over the wireless network. LTE parameters and frequency bands What is OFDMA? OFDMA multiple access and downlink frame structure OFDMA transmit and receive chains Here are some important parameters and downlink modulation techniques used in LTE: … Read more
The state-of-the-art design of the LTE air interface is characterised by OFDMA (DL) and SC-FDMA (UL) together with MIMO. The downlink modulation is based on OFDMA (Orthogonal Frequency Division Multiple Access). OFDMA is a variant of OFDM which has the advantage that receiver complexity is at a reasonable level, it can handle scalable bandwidth requirements … Read more
Transmitting: After being processed at the MAC layer, the downlink data is sent to the physical layer inthe format of MAC PDU. The MAC PDU arranges the data block size according to the allocation results of radio resources at the MAC layer. After the data packets are processed through the channel coding, modulation, and IFFT … Read more
OFDMA is essentially a hybrid of FDMA and TDMA: Users are dynamically assigned subcarriers (FDMA) in different time slots (TDMA) . The advantages of OFDMA start with the advantages of single-user OFDM in terms of robust multipath suppression and frequency diversity. In addition, OFDMA is a flexible multiple-access technique that can accommodate many users with … Read more
In UL, the UE has no dedicated resources to transmit directly when new data arrived in the buffer from higher layer. It requests resources to transmit them. It receives radio resources. It transmits them. The scheduling request is sent on the Physical Uplink Control Channel (PUCCH). This channel carries radio signaling in uplink: Scheduling … Read more
Less complex modulation. OFDM is a simpler modulation technique that is better suited to deployments that do not require support for mobility. License-exempt bands. Mobile services require licensed spectrum to provide coverage in wide areas. Fixed deployments, however, have often successfully used license-exempt bands in areas where interference levels are acceptable. For this reason, most … Read more
In 1998, the Institute of Electrical and Electronics Engineers (IEEE) formed a group called 802.16 to develop a standard for what was called a wireless metropolitan area network, or wireless MAN. Originally, this group focused on developing solutions in the 10GHz to 66GHz band, with the primary application being delivering high-speed connections to businesses that … Read more
How Many OFDMA Parameter for LTE? Which is OFDMA Parameter for LTE ? The width of a Sub-carrier is 15 kHz whatever the bandwidth The bandwidths are: 1.4, 3, 5, 10, 15 and 20 MHz Note that in LA1.1, only 5, 10 MHz are implemented The symbol duration is always the same whatever the bandwidth … Read more
what is main Difference between DL and UL in LTE ? OFDMA Advantages Robust against narrow-band co-channel interference Robust against Intersymbol interference (ISI) and fading High spectral efficiency Efficient implementation using FFT Drawbacks High Peak-to-Average Power Ratio The power limitation is more problematic in UL than in DL Signal with high PAPR will limit the … Read more