Tag: ofdma

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…

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…

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…

The guard period after each rectangular pulse carrying the modulated data symbol is a simple and efficient method to deal with multi-path reception. The cyclic prefix (CP) simply consists of…

The receiver is like in any other radio system the more complicated part. In radio systems and of course also OFDM there are two special points a receiver has to…

A typical OFDM transmitter is shown on the following figure. To reduce the amount of RF hardware required for OFDM the modulation process is split into two parts. A first…

FDM in LTE Conventional multi-carrier operation as it is used for FDM works simply by selecting a number of center frequencies – one for each carrier to be used. The…

The price for the optimum subcarrier spacing is the sensitivity of OFDM to frequency errors. If the receiver’s frequency is some fractions of the subcarrier spacing (subcarrier bandwidth) then we…

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…

 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…