Performance Evaluation of Mimo Ofdm

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MEE10:60

Performance analysis of MIMO-OFDM Systems with focus on WiMAX

Muhammad Hassan Email: m_hassan786@yahoo.com Abdul Sattar Email: abdulsattar2005@hotmail.com

This thesis is presented as part of Degree of Master of Science in Electrical Engineering Blekinge Institute of Technology, Sweden 2010 ________________________________________________________________Supervisor: Maria Erman Examiner: Dr. Jorgen Nordberg

Performance analysis of MIMO-OFDM Systems with focus on WiMAX

2010

Abstract:The demand of different multimedia services and different internet supported applications on mobile devices requires a high speed data rate and good service of quality. This can be obtained by implementing multiple Antenna technology on both stations i.e. User terminal and base station with an appropriate coding technique, and on the other hand MIMO can fulfill 3G & 4G demand and standard with a combination of other techniques. The MIMO diversity and MIMO multiplexing are the key factors to discuss and matter of concern is to achieve and support high speed data rate. MIMO multiplexing is a way to gain robustness and achievement in speed of data information. This thesis work describes a brief overview of WiMAX technology and MIMOOFDM system and it also discusses the simplest Space time block code (STBC) known as Alamouti Space Time Code. The research approach is a literary survey to have theoretical understanding of the MIMO-OFDM system and WiMAX. The systems error performance is analyzed through simulation which showed the simulated results of Multi-Rate Resource Control (MRRC) scheme and Alamouti scheme are identical. And also the Bit Error Rate (BER) were checked for different MIMO systems, the simulation results shows that the BER improved to agreeable value also gains maximum diversity when the number of antennas increased on the receiver side. By improving the BER, we will get the better QoS. Matlab simulation has been performed, and presented the results, which shows the considerable error free transmission (FEC) for MIMO systems in WiMAX technology.

Blekinge Tekniska Hgskola, KarlsKrona

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Performance analysis of MIMO-OFDM Systems with focus on WiMAX

2010

Acknowledgment:In the name of greatest All mighty ALLAH who has always bless me with potential knowledge and success. We are very thankful to our supervisor Maria Erman for her supervision and Examiner Dr. Jrgen Nordberg for their support during our thesis. We are also thankful to our friends who help us during our hard times when we need their assistance during our thesis report. We are especially thankful to our parents, brothers and sisters who have always provided us the courage, strength, best wishes, moral and financial support during our whole career. We also have best regards for BTH faculty especially Mikael sman and Lena Magnusson who had been helpful throughout our masters degree.

Blekinge Tekniska Hgskola, KarlsKrona

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Performance analysis of MIMO-OFDM Systems with focus on WiMAX

2010

Table of ContentsAbstract: ..................................................................................................................................... 2 Acknowledgment: ...................................................................................................................... 3 Table of Contents ....................................................................................................................... 4 List of Figures ........................................................................................................................ 7 List of Acronyms ................................................................................................................... 8 CHAPTER 1:............................................................................................................................ 10 1.1 1.2 1.3 Introduction ................................................................................................................... 10 Aims and Achievements ................................................................................................ 10 Thesis Structure: ............................................................................................................ 11

CHAPTER 2: The IEEE (Standards) ....................................................................................... 12 2.1 2.2 THE IEEE (Standards-Based Solutions) ....................................................................... 12 Overview of the IEEE Standards .................................................................................. 12

2.2.1 IEEE 802.11.............................................................................................................. 12 2.2.2 IEEE 802.16.............................................................................................................. 13 2.2.3 2-11 GHz & 10-66 GHz ........................................................................................... 14 2.3 How the IEEE 802.16 Works ........................................................................................ 15 2.4 2.5 Fading ............................................................................................................................ 16 The propagation of wireless Channels .......................................................................... 16

2.5.1 The Ground wave propogation ................................................................................. 17 2.5.2 The Sky wave propagation ....................................................................................... 17 2.5.3 The Line of sight propagation .................................................................................. 18 CHAPTER 3: Multi Carrier Modulation .................................................................................. 20 3.1 Multi-Carrier Modulation .............................................................................................. 20

3.1.1 FDM and OFDM ...................................................................................................... 21 3.2 OFDM ........................................................................................................................... 21 3.2.2 Fourier Transform..................................................................................................... 23 3.2.3 Guard Band ............................................................................................................... 23 3.2.4 Interleaving ............................................................................................................... 24 3.2.5 Windowing ............................................................................................................... 24 3.2.6 Peak to average power ratio...................................................................................... 25 3.3 OFDM Design Issues .................................................................................................... 26 3.3.1 Useful symbol duration ............................................................................................ 26 3.3.2 Number of carriers .................................................................................................... 26 3.3.3 Modulation scheme................................................................................................... 26 3.4 Advantages of OFDM ................................................................................................... 26Blekinge Tekniska Hgskola, KarlsKrona

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Performance analysis of MIMO-OFDM Systems with focus on WiMAX

2010

3.5

Disadvantages of OFDM ............................................................................................... 27

CHAPTER 4: Multiple Input Multiple Output ........................................................................ 28 4.1 4.2 MIMO Systems ............................................................................................................. 28 Channel Capacity .......................................................................................................... 29

4.2.1 Channel capacity for SISO ....................................................................................... 29 4.2.2 Channel Capacity for MISO ..................................................................................... 29 4.2.3 Channel capacity for SIMO ...................................................................................... 30 4.2.4 Channel capacity for MIMO..................................................................................... 30 4.3 Advantages of MIMO ................................................................................................... 32 CHAPTER 5: Space Time Coding ........................................................................................... 33 5.1 Space Time Coding ....................................................................................................... 33

5.1.1 Differentials STBC ................................................................................................... 33 5.2 Alamouti Space Time Code .......................................................................................... 33 5.2.2 Alamouti Scheme ..................................................................................................... 33 5.2.2.1 21 Alamouti Scheme ....................................................................................... 34 5.2.3 Higher Order Alamouti scheme ................................................................................ 35 5.3 Feed Back Analysis ....................................................................................................... 36 5.3.1 Feed b