THÔNG TIN DI ĐỘNG C2
Outline Introduction Cellular mobile communications Chapter 1: Introduction to Mobile Communications Nguyen Le Hung Mobile Communications Chapter 1: Introduction to Mobile Communications 1 Outline Introduction Cellular mobile communications Outline of Chapter 1 1 Introduction Development of mobile communication systems Mobile broadband technology evolution Promises and future trends 2 Cellular mobile communications System model Frequency reuse Cellular concept Mobile Communications Chapter 1: Introduction to Mobile Communications 2 Outline Introduction Cellular mobile communications Development of mobile communication systems Mobile broadband technology evolution Promises and future trends Development of mobile communications systems time code frequency code space FDMA (1G) e.g., AMPS ~ 1980s TDMA (2G) e.g., GSM ~ 1990s OFDM, SDMA (4G) e.g., WiMAX, LTE 2010s CDMA (3G) e.g., W-CDMA ~ 2000s frequency time time ~ 1 Gbps (stationary), ~ 100 Mbps (mobile) frequency frequency ~ 14 Mbps (downlink), ~ 5.8 Mbps (uplink) ~ 50 Kbps A new signal dimension will be exploited in 5G ? Mobile Communications Chapter 1: Introduction to Mobile Communications 3 Outline Introduction Cellular mobile communications Development of mobile communication systems Mobile broadband technology evolution Promises and future trends OFDM versus FDMA Frequency Mobile Communications Chapter 1: Introduction to Mobile Communications 4 Outline Introduction Cellular mobile communications Development of mobile communication systems Mobile broadband technology evolution Promises and future trends Mobile broadband technology evolution LTE Advanced 802.16m R 2.0 WCDMA 3GPP HSDPA HSPA Mobile WiMAX 802.16e R 1.0 EVDO Rev A EVDO Rev B CDMA 2000 3GPP2 LTE 802.16e R 1.5 2005 2009 20102006 2007 2008 2011 2012 CDMA based OFDMA based R99 “4G” IMT-Advanced Mobile Communications Chapter 1: Introduction to Mobile Communications 5 Outline Introduction Cellular mobile communications Development of mobile communication systems Mobile broadband technology evolution Promises and future trends Promises 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 Chapter 1: Introduction to Mobile Communications 6 Outline Introduction Cellular mobile communications System model Frequency reuse Cellular concept System model of cellular mobile communications BTS LTE/LTE Ͳ Advanced Single Cell MultiͲcell approach using game theory Uplink (SCͲFDMA), limited feedback design Downlink (OFDMA) SingleͲUser Multiuser Precoding (SDMA) MultiͲhop Relay BTS BTS BTS BTS InterͲcell interference InterͲcell interference SingleͲuser/MultiͲhop: Channel Estimation, Synchronization (CFO), Channel Coding, . Network Controller STBC with highͲspeed users (large Doppler spread) Cognitive radio Space Time Block Code: STBC; PeakͲtoͲAverage Power Ratio: PAPR; VͲOFDM UserͲcooperation (cooperative/multiͲhop communications) Mobile Communications Chapter 1: Introduction to Mobile Communications 7 Outline Introduction Cellular mobile communications System model Frequency reuse 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 8 Outline Introduction Cellular mobile communications System model Frequency reuse 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 𝑁 = 𝑖 2 + 𝑖𝑗 + 𝑗 2 , (1) where 𝑖 and 𝑗 are non-negative integers and 𝑖 ≥ 𝑗. It follows that the allowable cluster sizes are 𝑁 = 1, 3, 4, 7, 9, 12, . . Mobile Communications Chapter 1: Introduction to Mobile Communications 9 Outline Introduction Cellular mobile communications System model Frequency reuse Cellular concept Cellular concept: Multicell layout with frequency-reuse 3-cell 4-cell 7-cell Macrocellular deployment with 7-cell clusters Macrocellular deployment with 3-cell clusters Mobile Communications Chapter 1: Introduction to Mobile Communications 10 . 802 .16 m R 2.0 WCDMA 3GPP HSDPA HSPA Mobile WiMAX 802 .16 e R 1. 0 EVDO Rev A EVDO Rev B CDMA 2000 3GPP2 LTE 802 .16 e R 1. 5 2005 2009 2 010 2006 2007 2008 2 011 . Outline Introduction Cellular mobile communications Chapter 1: Introduction to Mobile Communications Nguyen Le Hung Mobile Communications Chapter 1: Introduction