Adopting a multicarrier approach for multiple access in LTE was the first major design choice. The choice of multiple-access schemes was made in December 2005, with OFDMA being selected for the downlink, and SC-FDMA
Tag : fdma
SC-FDMA utilizes single carrier modulation, DFT-spread orthogonal frequency multiplexing, and frequency domain equalization. LTE uses OFDMA on the DL. It allocates DL bandwidth to the user based on resource blocks, rather than individual subcarriers.
Introduction to SC-FDMA and uplink frame structure Marriage of single carrier transmission and FDMA Uplink SC-FDMA tranmsit and receive chains Peak to Average Power Ratio (PAPR) comparison with SC-FDMA and OFDMA
LTE OFDMA and Downlink Frame Structure Details Downlink OFDMA time-frequency multiplexing LTE Spectrum Flexibility and Bandwidth FDD downlink frame structure detailed TDD frame structure LTE (any OFDM/OFDMA) band is made up of multiple small
LTE parameters and frequency bands What is OFDMA? OFDMA multiple access and downlink frame structure OFDMA transmit and receive chains
The uppermost evolution track shown in Figure is that developed in the 3rd Generation Partnership Project (3GPP), which is currently the dominant standards development group for mobile radio systems and is described in more
The TDMA/FDMA multiplexing is used in GSM, the information needed in the synchronization between MS and BTS is provided by FCCH+SCH. The MS determines the frequency of the BCCH carrier by searching for the
The major basic concept concerned with the radio path transmission of the GSM system is the burst sequence (simplified as Burst). It is a string of transmission units including more than 100 modulation bits.
Figure shows how the two codewords are used for a single user in the downlink. It is also possible that the code words to be assigned to different users to create multi-user MIMO (MU-MIMO).
SRNC and DRNC are concepts for a connected UE. The SRNC handles the connection to one UE, and may borrow radio resources of a certain cell from the DRNC. Drift RNCs support the Serving
Threre are four Different Methods to Combine OFDMA for handle Multiuser System. Plain OFDM: Normal LTE OFDM has no built-in multiple-access mechanism. This is suitable for broadcast systems like DVB-T/H which transmit only broadcast
Scheduling Principle Deployment of shared channels offers the possibility for scheduling. In this way information on varying channel conditions can be exploited to increase the overall throughput. Fast scheduling in time (1 ms) and