Sharif Digital Repository

Today, the “wireless” is used almost synonymously with radio-frequency (RF) technologies as a result of the wide-scale deployment and utilization of wireless RF devices and systems. The RF band ranges from 300 kHz to 300 GHz and its use is regulated by regional and international agencies. With the ever-growing popularity of data-heavy wireless communications, wireless products and services, the demand for RF spectrum is outstripping supply, which causes the spectrum congestion. Therefore, the time has come to seriously consider other viable options for wireless communication using the upper parts of the electromagnetic spectrum. In this way, the optical band which includes infrared, visible,... 

Daily improvements in technology and exchanging important information via internet and connection networks make data and connection security a significant problem. Cryptology is the branch of knowledge which concerns secret communications in all of its aspects. Two major areas of cryptology are cryptography and cryptanalysis. Cryptography is a branch of cryptology concerned with protecting communications from being read by unauthorized people.
Cryptologists design and create algorithms to improve cryptography along with finding methods to crack those algorithms. Cryptanalysis is a branch of cryptology concerned with cracking the cryptographic systems used by others.
Cryptographic... 

ITRS shows next generation of Multiprocessor System on Chip (MPSoCs) designs will contain hundreds of heterogeneous cores, running at different speeds and voltage levels. Networks-On-Chip (NoC) provide a structured way of realizing interconnections on silicon, and obviate the limitations of bus-based solution. As the number of components in MPSoCs increases, the interconnect schemes based on NoC approach are increasingly used. However, NoC designs have many power, area, and performance trade-offs in topology, buffer sizes, routing algorithms and flow control mechanisms, hence the study of new NoC designs can be very time-intensive.
To address these challenges, we propose a new... 

An implementation of Digital Section of a DVB-T receiver has been introduced in this research. Nowadays, low-power and area-efficient designs have proven their importance in IC design aspect, so many low-power and area efficient approaches have been considered in this implementation. This design has been segregated into independent blocks, and each of them has been designed respect to the design goals. After that, all these blocks linked together and a whole system design implemented in gate level, then downloaded into a FPGA (Field programmable Gate Array) to test the timing and functionality of implemented blocks. In this thesis, some innovations have been introduced. A new algorithm for... 

Providing high bandwidth network infrastructures for ever increasing need of data transport is of great importance. The underling infrastructure for many communication services such as GSM/3G/4G mobile networks and Internet services is Synchronous Digital Hierarchy (SDH) optical transport systems. SDH are standardized protocols that multiplex multiple lower rate digital bit streams, such as E1 and Ethernet, and transfer them synchronously over optical fiber using lasers or LEDs. In addition to high data transfer rates, flexible network management and protection mechanisms have great importance, hence are part of SDH standards. In order to obtain flexible network architecture and protected... 

Due to the data centers rapid growth and introduction of a new basic type of massive data processing platforms which requires accelerators to speedup computation and enhance the efficiency and reduce power consumption, using accelerators is inevitable. Communication and data transfer time between software and hardware is the most of time spent on the use of accelerators. By optimizing this part of the hardware / software platform, we have achieved substantial results in this area. The aim of our study is to organize a survey of real accelerator characteristics. To figure out its defects and main drawbacks, in addition to improving the overall efficiency of system. The implementation of... 

Reliable communication has become very crucial in the transmission applications. Hence, to design hardware to handle reliability is the most important part of communication. In this work, we propose a new secured ALU (Arithmetic and Logic Unit) against fault attacks that is used in ARM processor which can correct any 5-bit error in any position of 32-bit input registers of ALU. We also designed a BCH (Bose, Chaudhuri, and Hocquenghem) codec (encoder, decoder) using the prototyping FPGA. Further, in this thesis we designed (63, 36) the BCH encoding and decoding system to tolerate the 5-bit faults. The codec system and ALU system are based on using Verilog description language. Since... 

Nowadays, embedded processors are widely used in wide range of domains from low-power to safety-critical applications. By providing prominent features such as variant peripheral support and flexibility to partial or major design modifications, Field-Programmable Gate Arrays (FPGAs) are used in industry for implementing either an entire embedded system or a Hardware Description Language (HDL)-based processor, known as soft-core processor. FPGA-based designs, however, suffer from high power consumption, large die area, and low performance that hinders common use of soft-core processors. In this thesis, we present an efficient reconfigurable architecture to implement embedded processors in... 

With the proliferation of Internet-based applications and malicious attacks, security has become one of the most influential aspects in the network and, it should be considered from the beginning steps of designing the network infrastructure. Based on the fact that pattern matching is considered as one of the most important roles of security devices or applications, it becomes an important procedure in firewalls that have been classified as security equipments which adopt a security mechanism in order to restrict the traffic exchanged between networks and particular users or certain applications. While the trend of using compressed traffic is drastically increasing, this type of traffic is... 

One the most important issues in most of embedded systems is reliability and fault tolerance.Ensure of correct operation and evaluate reliability and fault tolerance of embedded proces-sors as a critical part of embedded systems, would be necessary. Fault injection is one themostly used methods for evaluating those features. Using FPGA devices is a good alterna-tive for time consuming simulation-based fault injection method because of their speed. But,there are some critical issues in FPGA-based fault injection methods which are controllabil-ity and observability. In addition to need for efficient and applicable observation and controlmechanism to handle fault injection experiments, a... 

Increasing complexity of embedded systems and the need for more computation powerhave directed designers toward using of multiprocessors. SRAM-based FPGAs are suitable platforms for implementation of multiprocessors due to thier low cost, fast time-to-market and re-configurability. FPGA-based multiprocessors are known as soft multiprocessors. The large area of SRAM-based FPGAs is occupied by configuration bits. Configuration bits are vulnerable to high energy particles that can lead to soft errors. In this regards, it is of decisive importance to protect soft multiprocessors against soft errors. This thesis proposes a fault-tolerant method for soft multiprocessors that can detect and... 

Achieving technical knowledge and technology of design, build, test and launch satellites in each country is a strategic issue due to extension of satellite applications in various aspects of human life. One of the most important subsystems of a satellite is the telecommand part. This part is responsible for decode, receive, interpret, and distribution of commands and data received from the ground station. This part in terms of reliability is the most critical part of satellite because it coordinates satellite and ground station and also is the part which should be turned on during the mission and controls other parts of satellite. In other words this part should be design with high... 

Software defined networks are developed to provide programmability and a centralized view in networks by decoupling control plane from data plane. Software defined networks are now well received,and these networks are evolving every day. This is while more attention has been paid to widen the application of these networks and eliminating the shortcomings in their performance. On the other hand, in very large networks, the issue of efficiency and processing speed is of great importance. However, performance in these networks is not satisfactory, especially in single controller based SDN due to the complex processing of packets in a unique controller. Security needs are also of great...