THÔNG TIN DI ĐỘNG C2

THÔNG TIN DI ĐỘNG C2

Introduction Cellular mobile communications

Nguyen Le Hung

Outline of Chapter 1

@ Introduction

@ Development of mobile communication systems

@ Mobile broadband technology evolution

@ Promises and future trends

@ Cellular mobile communications

@ System model

@ Frequency reuse

@ Cellular concept

Mobile Communications Chapter 1: Introduction to Mobile Communications

Introduction Mobile broadband technology evolution

Promises and future trends

Development of mobile communications systems

~ 1 Gbps (stationary),

~ 14 Mbps (downlink),

~ 5.8 Mbps (uplink)

a

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Introduction Mobile broadband technology evolution

Promises and future trends

OFDM versus FDMA

0 200 400 600 800 100 1,200

Frequency (Hz)

Mobile Communications Chapter 1: Introduction to Mobile Communications

broadband technology evolution

2005 2006 2007 2008 2009 2010 2011 2012

3GPP

“AG”

CDMA 2000 'IMT-Advanced

Mobile i 3

WiMAX :

Introduction Cellular mobile communications

and future trends

multimedia services: Voice, Video distribution, Real- time videoconferencing, Data, for both business and residential customers:

» Explosive traffic growth

» Internet growth, VoIP, VideoIP, IPTV Cell phone popularity worldwide Ubiquitous communication for people and devices Emerging systems opening new applications Unified network: Single distributed network,

multiple services, packet architecture

Extracted from Digital Communication lecture notes, McGill Uni

Mobile Communications

Ce

System model

Introduction llular mobile communications

Frequency reuse Cellular concept

of cellular mobile communications

z “oN

ie \

œ = nn

Network Controller

LTE/LTE - Advanced

Single-user/Multi-hop: N Channel Estimation, Synchronization (CFO), Channel Coding,

ownlink 8

\

`

⁄ “Multiuser Precoding

Uplink (SC-FDMA), limited feedback design

User-cooperation (cooperative/multi-hop communications)

_—

single Cell Cognitive radio

STBC with high-speed users (large Doppler spread)

Introduction Frequency reuse Cellular mobile communications Cellular concept

Frequency reuse

@ The available spectrum is partitioned among the base stations (BSs)

@ A given frequency band is reused at the closest possible

distance under a certain requirement of co-channel

interference

@ Smaller cells have a shorter distance between reused

frequencies == an increased spectral efficiency

@ Microcells are of great importance in improving spectral

efficiency

@ Under frequency-reuse, users in geographically separated cells simultaneously employ the same carrier frequency

Mobile Communications Chapter 1: Introduction to Mobile Communications

Introduction Frequency reuse Cellular mobile communications Cellular concept

Cellular concept

@ The cellular layout of a conventional cellular system is quite

often described by a uniform grid of hexagonal cells or radio

coverage zones

@ In practice the cells are not regular hexagons, but instead are

distorted and overlapping areas

@ The hexagon is an ideal choice for representing macrocellular

coverage areas, because it closely approximates a circle and

offers a wide range of tessellating reused cluster sizes

@ A tessellating reuse cluster of size N can be constructed if

Introduction Cellular mobile communications

oncept: Multicell layout with frequency-reuse

ee ^

Macrocellular deployment Macrocellular deployment with 7-cell clusters with 3-cell clusters

Mobile Communications