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/s
18Mb/s
100Mb/s
1000Mb/s
Standards availability
Enter the password to open this PDF file:
File name:
-
File size:
-
Title:
-
Author:
-
Subject:
-
Keywords:
-
Creation Date:
-
Modification Date:
-
Creator:
-
PDF Producer:
-
PDF Version:
-
Page Count:
-
Preparing document for printing…
0%
Comments 0
Log in to post a comment