24-07-2012, 02:40 PM
LONG TERM EVOLUTION
LONG TERM EVOLUTION.pptx (Size: 537.79 KB / Downloads: 34)
INTRODUCTION
3GPP Long Term Evolution, referred to as LTE.
3GPP refers to 3rd Generation Partnership Project
3GPP work on the Evolution of the 3G Mobile System started in November 2004
The world's first publicly available LTE service was launched by TeliaSonera in Norway on 14 December 2009
3 GPP
The 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations, known as the Organizational Partners.
The initial scope of 3GPP was to make a globally applicable third-generation (3G) mobile phone system specification based on evolved GSM specifications.
LTE PERFORMANCE
Data Rate:
Instantaneous downlink peak data rate of 100Mbit/s in a20MHz downlink spectrum (i.e. 5 bit/s/Hz)
Instantaneous uplink peak data rate of 50Mbit/s in a 20MHz uplink spectrum (i.e. 2.5 bit/s/Hz)
Cell range
5 km - optimal size
30km sizes with reasonable performance up to 100 km cell sizes supported with acceptable performance
KEY FEATURES
Multiple access scheme
Downlink: OFDMA
Uplink: Single Carrier FDMA (SC-FDMA)
Adaptive modulation and coding
DL modulations: QPSK, 16QAM, and 64QAM
UL modulations: QPSK and 16QAM
Support for both FDD and TDD
SC-FDMA
The LTE uplink transmission scheme for FDD and TDD mode is based on SC-FDMA (Single Carrier Frequency Division Multiple Access).
This is to compensate for a drawback with normal OFDM, which has a very high Peak to Average Power Ratio (PAPR). High PAPR requires expensive and inefficient power amplifiers with high requirements on linearity, which increases the cost of the terminal