CELLULAR COMMUNICATIONS

LTE

Data Rate

Requirements And Targets to LTE reduced delays, in terms of both connection

establishment and transmission latency; increased user data rates; increased cell-edge bit-rate, for uniformity of service

provision; reduced cost per bit, implying improved spectral

efficiency; greater flexibility of spectrum usage, in both new and

pre-existing bands; simplified network architecture; seamless mobility, including between different radio-

access technologies; reasonable power consumption for the mobile terminal

Cell/User Throughput

Average cell throughput [bps/cell] and spectral efficiency [bps/Hz/cell].

Average user throughput [bps/user] and spectral efficiency [bps/Hz/user].

Cell-edge user throughput [bps/user] and spectral efficiency [bps/Hz/user]. The metric used for this assessment is the

5-percentile user throughput, obtained from the cumulative distribution function of the user throughput.

Key Performance Requirements

Key Performance Requirements

Multiple Antenna Technology Diversity gain. Use of the space-diversity provided

by the multiple antennas to improve the robustness of the transmission against multipath fading.

Array gain. Concentration of energy in one or more given directions via precoding or beamforming. This also allows multiple users located in different directions to be served simultaneously (so-called multi-user MIMO).

Spatial multiplexing gain. Transmission of multiple signal streams to a single user on multiple spatial layers created by combinations of the available antennas.

MIMO

Packet-Switched Radio Interface Completely Packet Oriented Systems

LTE User Equipment

Network

The Access Network

Bearers

Minimum Guaranteed Bit Rate (GBR) bearers which can be used for applications such as VoIP. have an associated GBR value for which

dedicated transmission resources are permanently allocated

Non-GBR bearers which do not guarantee any particular bit rate. web browsing or FTP transfer. bandwidth resources are allocated permanently

to the bearer.

QoS

Handover

Lossless Handover

Logical and Physical Channel

Discontinuous Reception(DRX) Reduce time in a reception mode in

order to save battery

Logical Channel Priority

OFDM

OFDM

Peak-To-Average Power Ratio PAPR

Power amplifiers that are linear at wide range of inputs are costly

Handset: Reduce PAPR

OFDMA

OFDMA/TDMA

Physical Layer

Channel Estimation Transmission distort the signal and add

noise

If transmitted signal is known, can estimate distortion and apply inverse transformation on other signals

Reference signal

Reference Signal

Two antennas

Link Adaptation

Channel Quality Indicator

Multiple Antenna

Multiple Antenna

Optimal Power Allocation

Multi-User Scheduling

Resource Scheduler

Partial Frequency Reuse

Partial Frequency Reuse

Handover

40

Evolution of the Radio Interface

EDGE EDGE+

W-CDMA HSPA HSPA+

2000

LTE LTE-Advanced

40

2010

384Kb/s 1Mb/s

384Kb/s 42Mb/s18Mb/s

100Mb/s 1000Mb/s

Standards availability