Browsing by Author "Gazi, O."

Now showing 1 - 20 of 21

Citation - Scopus: 1
A New Companding Technique for Papr Reduction in Ofdm Communication Systems
(2011) Gazi, O.; Gazi, Orhan; 102896; Elektronik ve Haberleşme Mühendisliği
One of the major disadvantages of OFDM communication systems is their high peak-to-average power ratio (PAPR) which degrades system performance when nonlinear power amplifiers are employed. Among the proposed PAPR tech- niques companding is favorable due to its simplicity and easy of implementation. In this article, using the arctan- gent function we propose a new compading technique for PAPR reduction. We compare the proposed technique to the previously suggested exponential companding, and μ- law companding methods. Via computer simulations it is verified that the proposed technique is better than exponen- tial and μ-law companding methods for PAPR reduction.
Citation - WoS: 12
Citation - Scopus: 17
A survey on belief propagation decoding of polar codes
(Editorial Board of Journal on Communications, 2021) Arli, A.C.; Gazi, Orhan; Gazi, O.; Elektronik ve Haberleşme Mühendisliği
The increasing data traffic rate of wireless communication systems forces the development of new technologies mandatory. Providing high data rate, extremely low latency and improvement on quality of service are the main subjects of next generation 5G wireless communication systems which will be in the people's life in the years of 2020. As the newest and first mathematically proven forward error correction code, polar code is one of the best candidates among error correction methods that can be employed for 5G wireless networks. The aim of this tutorial is to show that belief propagation decoding of polar codes can be a promising forward error correction technique in upcoming 5G frameworks. First, we survey the novel approaches to the belief propagation based decoding of polar codes and continue with the studies about the simplification of these decoders. Moreover, early detection and termination methods and concept of scheduling are going to be presented throughout themanuscript. Finally, polar construction algorithms, error types in belief propagation based decoders and hardware implementations are going to be mentioned. Overall, this tutorial proves that the BP based decoding of polar codes has a great potential to be a part of communication standards. © 2013 China Institute of Communications.
Citation - Scopus: 2
A Tutorial Introduction to VHDL Programming
(Springer Singapore, 2018) Gazi, O.; Gazi, Orhan; 102896; Elektronik ve Haberleşme Mühendisliği
This book helps readers create good VHDL descriptions and simulate VHDL designs. It teaches VHDL using selected sample problems, which are solved step by step and with precise explanations, so that readers get a clear idea of what a good VHDL code should look like. The book is divided into eight chapters, covering aspects ranging from the very basics of VHDL syntax and the module concept, to VHDL logic circuit implementations. In the first chapter, the entity and architecture parts of a VHDL program are explained in detail. The second chapter explains the implementations of combinational logic circuits in VHDL language, while the following chapters offer information on the simulation of VHDL programs and demonstrate how to define data types other than the standard ones available in VHDL libraries. In turn, the fifth chapter explains the implementation of clocked sequential logic circuits, and the sixth shows the implementation of registers and counter packages. The book’s last two chapters detail how components, functions and procedures, as well as floating-point numbers, are implemented in VHDL. The book offers extensive exercises at the end of each chapter, inviting readers to learn VHDL by doing it and writing good code. © Springer Nature Singapore Pte Ltd. 2019.
Citation - Scopus: 0
Analog and digital filter design
(Springer Science and Business Media B.V., 2018) Gazi, O.; Gazi, Orhan; Elektronik ve Haberleşme Mühendisliği
In this chapter, we will study analog and digital filter design techniques. A filter is nothing but a linear time invariant (LTI) system. Any LTI system can be described using its impulse response. If the impulse response of a LTI system is known, then for any arbitrary input the system output can be calculated by taking the convolution of the impulse response and arbitrary input. This also means that filtering operation is nothing but a convolution operation. And filter design is nothing but finding the impulse response of a linear time invariant system. For this purpose, we can work either in time domain or frequency domain. © Springer Nature Singapore Pte Ltd. 2018.
Citation - Scopus: 0
Channel Coding Theorem
(Springer Science and Business Media Deutschland GmbH, 2018) Gazi, O.; Gazi, Orhan; 102896; Elektronik ve Haberleşme Mühendisliği
In this chapter, we will discuss the channel coding theorem in details. Channel coding theorem can be accepted as a milestone in electronic communication field. For this reason, it is very critical for a communication engineer to comprehend the channel coding theorem very well. In many information theory books, or in many lecture notes delivered in classes about information theory, channel coding theorem is very briefly summarized, for this reason, many readers fail to comprehend the details behind the theorem. © 2018, Springer Nature Singapore Pte Ltd.
Citation - Scopus: 0
Concept of Information, Discrete Entropy and Mutual Information
(Springer Science and Business Media Deutschland GmbH, 2018) Gazi, O.; Gazi, Orhan; 102896; Elektronik ve Haberleşme Mühendisliği
In this chapter, we will try to explain the concept of information, discrete entropy and mutual information in details. To master on the information theory subjects, the reader should have a knowledge of probability and random variables. For this reason, we suggest to the reader to review the probability and random variables topics before studying the information theory subjects. Continuous entropy and continuous mutual information are very closely related to discrete entropy and discrete mutual information. For this reason, the reader should try to understand very well the fundamental concepts explained in this chapter, then proceed with the other chapters of the book. © 2018, Springer Nature Singapore Pte Ltd.
Citation - Scopus: 1
Discrete Fourier Transform
(Springer Science and Business Media B.V., 2018) Gazi, O.
In linear algebra, basis vectors span the entire vector space. And any vector of the vector space can be written as the linear combination of the basis vectors. For any vector in vector space, finding the coefficients of basis vectors used for the construction of the vector can be considered as a transformation. Fourier series are used to represent periodic signals. Fourier series are used to construct any periodic signal from sinusoidal signals. The sinusoidal signals can be considered as the basis signals, and linear combination of these signals with complex coefficients produce any periodic signal. © Springer Nature Singapore Pte Ltd. 2018.
Citation - Scopus: 0
Efficient decoding of polar codes
(Springer Science and Business Media B.V., 2019) Gazi, O.
As we explained in Chap. 1, polar encoder structures can be constructed in a recursive manner. This leads to recursive decoding structures. In [1], Arıkan proposed successive cancellation decoding algorithm for the decoding of polar codes and derived recursive expression for the decoding operations. © Springer Nature Singapore Pte Ltd. 2019.
Citation - Scopus: 0
Entropy for Continuous Random Variables Discrete Channel Capacity, Continuous Channel Capacity
(Springer Science and Business Media Deutschland GmbH, 2018) Gazi, O.; Gazi, Orhan; 102896; Elektronik ve Haberleşme Mühendisliği
In this chapter, we will study the entropy concept for continuous random variables. The capacity of both continuous and discrete channels will be inspected in details. The capacity formula for additive white Gaussian channel is to be derived and the factors that affects the capacity of the additive white Gaussian channel will be elaborated. © 2018, Springer Nature Singapore Pte Ltd.
Citation - Scopus: 11
Forward Error Correction via Channel Coding
(Springer International Publishing, 2019) Gazi, O.; Gazi, Orhan; 102896; Elektronik ve Haberleşme Mühendisliği
This book provides a comprehensive explanation of forward error correction, which is a vital part of communication systems. The book is written in such a way to make the subject easy and understandable for the reader. The book starts with a review of linear algebra to provide a basis for the text. The author then goes on to cover linear block codes, syndrome error correction, cyclic codes, Galois fields, BCH codes, Reed Solomon codes, and convolutional codes. Examples are provided throughout the text. Provides a comprehensive treatment of forward error correction Includes examples through the book, which are solved in steps, making them easier to understand Ideal for researchers, professionals and students. © Springer Nature Switzerland AG 2020.
Citation - Scopus: 0
Information theory for electrical engineers
(Springer Science and Business Media Deutschland GmbH, 2018) Gazi, O.; Gazi, Orhan; 102896; Elektronik ve Haberleşme Mühendisliği
Citation - Scopus: 1
Mathematical modelling of polar codes, channel combining and splitting
(Springer Science and Business Media B.V., 2019) Gazi, O.; 102896
In Chap. 2, we explained the decoding of polar codes in a clear and trivial manner. However, in most of the engineering sciences, it is critical to mathematically formulate the theories or techniques invented. © Springer Nature Singapore Pte Ltd. 2019.
Citation - Scopus: 2
Multirate Signal Processing
(Springer Science and Business Media B.V., 2018) Gazi, O.
Digital signals are obtained from continuous time signals via sampling operation. Continuous time signals can be considered as digital signals having infinite number of samples. Sampling is nothing but selecting some of these samples and forming a mathematical sequence called digital signal. And these digital signals can be in periodic or non-periodic forms. © Springer Nature Singapore Pte Ltd. 2018.
Citation - Scopus: 1
Polar codes: A non-trivial approach to channel coding
(Springer Science and Business Media B.V., 2019) Gazi, O.; Gazi, Orhan; 102896; Elektronik ve Haberleşme Mühendisliği
Polar codes are one of the recently discovered capacity achieving channel codes. What makes the polar codes different from other channel codes is that polar codes are designed mathematically and their performance are mathematically proven. © Springer Nature Singapore Pte Ltd. 2019.
Citation - Scopus: 0
Polarization of binary erasure channels
(Springer Science and Business Media B.V., 2019) Gazi, O.; Gazi, Orhan; 102896; Elektronik ve Haberleşme Mühendisliği
In this chapter, we will demonstrate the calculation of split channel capacities when polar codes are employed for binary erasure channels. © Springer Nature Singapore Pte Ltd. 2019.
Citation - Scopus: 0
Polarization rate and performance of polar codes
(Springer Science and Business Media B.V., 2019) Gazi, O.; Gazi, Orhan; 102896; Elektronik ve Haberleşme Mühendisliği
In this chapter, we will mathematically state the channel polarization theorem and prove it. In addition, the performance of polar codes will be mathematically analyzed. © Springer Nature Singapore Pte Ltd. 2019.
Citation - Scopus: 4
Principles of Signals and Systems
(Springer International Publishing, 2022) Gazi, O.
The textbook presents basic concepts of signals and systems in a clear manner, based on the author's 15+ years of teaching the undergraduate course for engineering students. To attain full benefit from the content, readers should have a strong knowledge of calculus and be familiar with integration, differentiation, and summation operations. The book starts with an introduction to signals and systems and continues with coverage of basic signal functions and their manipulations; energy, power, convolution, and systems; Fourier analysis of continuous time signals and digital signals; Laplace transform; and Z transforms. Practical applications are included throughout. The book is also packed with solved examples, self-study exercises, and end of chapter problems. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.
Citation - WoS: 2
Citation - Scopus: 6
A Sequential Coding Approach for Short Length Lt Codes Over Awgn Channel
(Institute of Electrical and Electronics Engineers Inc., 2017) Abdulkhaleq, N.I.; Gazi, O.
Luby Transform (LT) codes which can be considered as one of the first type of rateless codes are introduced to be an efficient erasure code. In such codes a fountain of encoded symbols is continuously transmitted until the successfully delivery of all the data packets. Whenever the receiver collects N noisy encoded symbols the decoding operation starts. Usually belief propagation (BP) algorithm is used to decipher the code and extract the k data symbols. In this paper, short length LT codes are generated using efficient sequential encoding approach (SEA) and performance measurements have been done over additive white Gaussian (AWGN) channel. This coding technique generates its degree in a repeated sequential manner which yields a mutual relation between adjacent codes that will be used in the decoding part. The decoding complexity of the proposed structure is similar to that of the Raptor codes. The simulation results show that the proposed approach has better performance in terms of error floor and successful decoding ratio when compared to LT codes using robust soliton distribution (RSD) and memory-based-RSD (MBRSD) even when supported by belief propagation-pattern recognition (BP-PR) technique. © 2017 IEEE.
Citation - Scopus: 8
State Machines using VHDL
(Springer International Publishing, 2021) Gazi, O.; Gazi, Orhan; Çagri Arli, A.; 10289; Elektronik ve Haberleşme Mühendisliği
This textbook teaches students techniques for the design of advanced digital systems using Field Programmable Gate Arrays (FPGAs). The authors focus on communication between FPGAs and peripheral devices (such as EEPROM, analog-to-digital converters, sensors, digital-to-analog converters, displays etc.) and in particular state machines and timed state machines for the implementation of serial communication protocols, such as UART, SPI, I2C, and display protocols, such as VGA, HDMI. VHDL is used as the programming language and all topics are covered in a structured, step-by-step manner. © Springer Nature Switzerland AG 2021. All rights reserved.
Citation - Scopus: 0
Typical Sequences and Data Compression
(Springer Science and Business Media Deutschland GmbH, 2018) Gazi, O.; Gazi, Orhan; Elektronik ve Haberleşme Mühendisliği
In this chapter, we will first provide information about typical sequences the introduce the data compression subject. In fact, the data compression subject is a direct consequence of the typical sequences. For this reason, it is very important to comprehend the concept of typical sequences to understand the data compression phenomenon. © 2018, Springer Nature Singapore Pte Ltd.