دکتر منصور نجاتی جهرمی

The use of telecommunication systems with high energy efficiency and high data rates along with the desired quality of services is the infrastructure of a command and control system (C4I) that should be used with the best quality of communication in times of crisis. The use of such a structure has a special place in modern defense systems. Therefore, the design of such systems has become a major challenge and a very important research field in the field of telecommunications. The increasing growth of wireless telecommunications and the high speed of multimedia data traffic and the presence of multiple users are associated with energy consumption, which has focused on energy efficiency and the optimal use of energy and power in telecommunications. Energy efficiency is considered as one of the major goals of wireless telecommunication systems design due to environmental and economic issues. . Multi-user multi-input multi-output systems are one of the new methods of telecommunications. In these systems, the use of hundreds of antennas in the base station improves energy efficiency. Increasing the number of system antennas increases the rate of information exchange, energy consumption and hardware, the introduction of a power selection model in multi-input multi-output multi-user systems increases energy efficiency. Important factors affecting energy efficiency are actual transmission power and power consumption in transmitter and receiver circuits, number of antennas, number of users and spatial correlation between antennas. In this paper, the algorithm for selecting the farthest antenna is proposed (antenna correlation), which leads to a significant improvement in energy efficiency compared to the conventional state.

ICT development has caused evolution in service delivery methods. With the increase in population density in urban areas, it is necessary to change and develop the infrastructures. Fiber optic network is a  sustainable communication platform in the smart city and supports all broadband and narrowband services. In this paper, the role of fiber optics in the smart home (with broadband capability) and mobile network (5G) are considered as the two main parts of a smart city. A techno-economic model of  communication infrastructure in the smart city (using multi-purpose fiber optic network with existing  resources consideration) is stated by mixed integer linear programming (MILP) method. In this literature, whilst providing fundamental communication in the smart city, decreasing the vulnerability to threats and increasing the percentage of security and reliability, technical requirements are met and the Capital Expenditure (CAPEX) of network is reduced, as well.

Absorbents are used in RCS reduction to prevent reflection of the wave and not interfere with the test wave.By reducing the amount of reflection in a wave using materials used in adsorbents, they reduce the reflection.The things that are to be considered in relation to these reflections are the effects of these waves, which are termed ”pure environmental reflections“, the error caused by not considering the pure reflections of the environment and other problems caused by weaknesses. The main wave of the note is noteworthy. In this research, the optimum thickness of adsorbent material has been determined using genetic and Particle Swarm Optimization (PSO) algorithms with the aim of determining the minimum amount of electromagnetic wave reflection. The genetic algorithm is used to adjust the plate resistance values as well as the PSO algorithm to determine the optimal screen thickness. The results show that determination of microwave absorption coating parameters has a significant effect on the absorption rate of the wave. The applied method provides the conditions for achieving optimal coverage.

Using the high-speed data communication systems, along with the quality of service desirable, is the infrastructure of a command and control system (C41) that should be used in the worst case scenario with the best transmission quality. The use of such a structure in the new defensive systems is very important research topics. As bandwidth increase to increase data rates is costly and sometimes impractical, the use of the orthogonal frequency division multiplexing systems (MIMO-OFDM) The main technology has become the 4G systems. Because of this,  multi-channel systems in wireless systems are used to improve the transmission quality and high-speed telecommunication data, and recently, Frequency-Time-Space Coding (STF) methods have been developed to improve multiplicity interest. The purpose of this paper is to analyze the MIMO-OFDM using a combination of beam shaping and STF techniques. The proposed STFBF method, which combines these two methods, performs better in terms of bit error rates than STF without beamforming and the proposed model is better than the combination of beamforming method and time-space block method (STBC).