Performance Analysis of MIMO-OFDM Systems with Focus on WiMAX

Performance Analysis of MIMO-OFDM Systems with Focus on WiMAX

Author: Muhammad Hassan

Publisher: LAP Lambert Academic Publishing

Published: 2017-06-16

Total Pages: 76

ISBN-13: 9783330329775

DOWNLOAD EBOOK

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 system's 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. By improving the BER, we will get the better QoS.


Design and Performance Analysis of a Low Complexity MIMO-OFDM System with Walsh Block Coding

Design and Performance Analysis of a Low Complexity MIMO-OFDM System with Walsh Block Coding

Author: Amr Hussein El Mougy

Publisher:

Published: 2006

Total Pages: 0

ISBN-13:

DOWNLOAD EBOOK

There are many technologies being considered for the next generation of wireless communications. Of these technologies, multi-input multi-output (MIMO), orthogonal frequency division multiplexing (OFDM) and Walsh spreading are drawing the most attention. Although a lot of research has been done in this area, it has not been decided yet as to which technology or combination of the technologies will be used in future wireless generations. The new generation will have to support high data rates and provide excellent performance in order to accommodate several multimedia services. In this thesis, a MIMO-OFDM system that employs Walsh sequences as block coding is designed. Simulation studies show that the proposed system exhibits high performance and comparisons show that it has low complexity compared to some of the previous systems. Two configurations are considered for the proposed system. The first configuration combines Vertical-Bell Labs Layered Space-Time (VBLAST), OFDM and Walsh block coding, for which a simplified implementation scheme for the proposed coding is presented. The system is investigated through extensive computer simulations using different system parameters and channel conditions. The proposed system is compared to some of the existing systems in terms of performance as well as computational complexity. The second configuration integrates space-time block coding (STBC), OFDM and Walsh block coding. In contrast to VBLAST, which aims to increase system capacity and data rates, STBC improves the system's performance through multipath diversity. The performance of the system is studied through computer simulations and the computational complexity of the system is also compared to some typical STBC systems from previous research. The simulations and comparisons of both configurations of the proposed system show its superiority in terms of performance and computational complexity to previous systems. Finally, to emulate real-life scenarios, the performance of the proposed system is also investigated using some common channel estimation techniques. It is shown that by utilizing a preamble of training symbols, the proposed system provides a satisfactory performance for both the configurations.


Channel Estimation and Performance Analysis of MIMO-OFDM Communications Using Space-time and Space-frequency Coding Schemes

Channel Estimation and Performance Analysis of MIMO-OFDM Communications Using Space-time and Space-frequency Coding Schemes

Author: Fabien Delestre

Publisher:

Published: 2011

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

This thesis is concerned with channel estimation and data detection of MIMO-OFDM communication systems using Space-Time Block Coding (STBC) and Space-Frequency Block Coding (SFBC) under frequency selective channels. A new iterative joint channel estimation and signal detection technique for both STBC-OFDM and SFBC-OFDM systems is proposed. The proposed algorithm is based on a processive sequence of events for space time and space frequency coding schemes where pilot subcarriers are used for channel estimation in the first time instant, and then in the second time instant, the estimated channel is used to decode the data symbols in the adjacent data subcarriers. Once data symbols are recovered, the system recursively performs a new channel estimation using the decoded data symbols as pilots. The iterative process is repeated until all MIMO-OFDM symbols are recovered. In addition, the proposed channel estimation technique is based on the maximum likelihood (ML) approach which offers linearity and simplicity of implementation. Due to the orthogonality of STBC and SFBC, high computation efficiency is achieved since the method does not require any matrix inversion for estimation and detection at the receiver. Another major novel contribution of the thesis is the proposal of a new group decoding method that reduces the processing time significantly via the use of sub-carrier grouping for transmitted data recovery. The OFDM symbols are divided into groups to which a set of pilot subcarriers are assigned and used to initiate the channel estimation process. Designated data symbols contained within each group of the OFDM symbols are decoded simultaneously in order to improve the decoding duration. Finally, a new mixed STBC and SFBC channel estimation and data detection technique with a joint iterative scheme and a group decoding method is proposed. In this technique, STBC and SFBC are used for pilot and data subcarriers alternatively, forming the different combinations of STBC/SFBC and SFBC/STBC. All channel estimation and data detection methods for different MIMO-OFDM systems proposed in the thesis have been simulated extensively in many different scenarios and their performances have been verified fully.


Performance Evaluation of Space Time/Frequency Codes in Mimo-Ofdm

Performance Evaluation of Space Time/Frequency Codes in Mimo-Ofdm

Author: Gunjan Manik

Publisher: LAP Lambert Academic Publishing

Published: 2012-05

Total Pages: 76

ISBN-13: 9783659108389

DOWNLOAD EBOOK

High spectral efficiency and high transmission data rate are the challenging requirements of wireless broadband communications. The MIMO technology has rapidly gained in popularity due to its powerful performance-enhancing capabilities. Spatial diversity can be obtained by using multiple antennas and space-time codes. For future wireless broadband systems, OFDM is discussed as access scheme. OFDM provides an essentially flat fading channel for each subcarrier by insertion of a cyclic guard interval at each antenna. Therefore, space-time block codes are well suited to be applied in OFDM. We investigate SFBC for OFDM systems with multiple transmit antennas, where coding is applied in the frequency domain rather than in the time domain. In this thesis, performance of two coding techniques STBC and SFBC is analyzed in OFDM. In order to appreciate the performances offered by coding through space and frequency, different simulation scenarios have been proposed where variation of the modulation order , channel fading, antenna selection technique, receiver diversity and effect of power conditions have been considered.


Advanced Computer and Communication Engineering Technology

Advanced Computer and Communication Engineering Technology

Author: Hamzah Asyrani Sulaiman

Publisher: Springer

Published: 2014-11-01

Total Pages: 1063

ISBN-13: 3319076744

DOWNLOAD EBOOK

This book covers diverse aspects of advanced computer and communication engineering, focusing specifically on industrial and manufacturing theory and applications of electronics, communications, computing and information technology. Experts in research, industry, and academia present the latest developments in technology, describe applications involving cutting-edge communication and computer systems and explore likely future directions. In addition, access is offered to numerous new algorithms that assist in solving computer and communication engineering problems. The book is based on presentations delivered at ICOCOE 2014, the 1st International Conference on Communication and Computer Engineering. It will appeal to a wide range of professionals in the field, including telecommunication engineers, computer engineers and scientists, researchers, academics and students.


Data Analytics and Management

Data Analytics and Management

Author: Ashish Khanna

Publisher: Springer Nature

Published: 2021-01-04

Total Pages: 920

ISBN-13: 9811583358

DOWNLOAD EBOOK

This book includes original unpublished contributions presented at the International Conference on Data Analytics and Management (ICDAM 2020), held at Jan Wyzykowski University, Poland, during June 2020. The book covers the topics in data analytics, data management, big data, computational intelligence, and communication networks. The book presents innovative work by leading academics, researchers, and experts from industry which is useful for young researchers and students.