Background and Objectives: To achieve significant throughput, Interference alignment (IA) is an encouraging technique for wireless Interference networks. In this study, we design an aligned beamformer based on the Interference leakage minimization (ILM) method to reduce the Interference power for a multiple-input multiple-output Interference channel (MIMO-IC). Methods: To deal with the non-convexity of ILM problem, we used a non-convex programming method (i. e., difference of convex [DC]). In this way, the Interference leakage function is reformulated to a DC function including difference of two convex terms. Then, an additive function is defined that includes the DC objective function and a penalty function. Results: We propose a novel DC-based IA algorithm that uses solutions of an upper bound of the additive function in each iteration; as the initial state for the next iteration. Through an iterative manner and for the large values of the penalty factor, the solutions of upper bound function converge to the solutions of the original DC objective function (i. e., Interference leakage function). Conclusion: In contrast to the frequent IA methods, the proposed DC-based IA algorithm updates transmit-and receive-beamformers in each iteration jointly (not alternately). Simulation results indicate that the proposed method outperforms some competitive IA algorithms by providing more throughputs and less Interference leakage.

In this paper, we evaluate various system configurations for crosstalk cancellation using Interference alignment (IA) in uncoordinated and partially coordinated downstream G. fast. In the first configuration, which can be implemented in a distributed fashion, signal-level coordination between users is unnecessary and IA is applied in the frequency domain. In the second configuration, partial signal-level coordination is available; however, it is entirely consumed by vectoring and IA is applied in the frequency domain. In the third configuration, partial signal-level coordination is available, but vectoring is not applied. Instead, IA is applied jointly in both the space and frequency domains. Considerably higher sum bit rates are achieved using the third configuration; however, the computational complexity is noticeably higher than the other two configurations. To tackle this problem, we propose a joint partial vectoring design based on the third configuration which outperforms the diagonalizing pre-compensator (a.k.a. zero-forcing precoder) considerably. Then we employ it in the second configuration to obtain a high-performance crosstalk cancellation scheme with much lower complexity. Our simulation results show that depending on the level of coordination, IA increases the achievable rates of G. fast loops significantly compared to available solutions with comparable complexity.

Growing demand to access frequency spectrum, cognitive radio is introduced so that the secondary users (SU) are allowed to use unused spectrum of primary user. If the primary user (PU) uses the full frequency spectrum, the existing unused spectrum in space-domain can create ideal opportunistic Interference alignment considering cognitive networks. Since the PU knows perfect channel knowledge, it can perform water-filling algorithm and singular value decomposition, then secondary users transmit along the spatial direction with the design pre-coder. In this paper, we improve the efficiency of the system with a transmit space-time coding technique introduced by Alamouti. In this regard, the SU transmit and receive antennas are reduced and after performing Interference alignment algorithm, but the Interference does not becomes exactly zero. In fact, to remove this Interference, SU transmits Alamouti code. In this paper, we consider the case of two secondary users opportunistically exploiting the same frequency band utilized by a licensed user. Our goal is to design low-complexity precoders to realize Interference cancellation for each secondary user. The main idea is to design precoders such that the two users transmit over two orthogonal spaces. As a result, the decoders can project the received signals to each of the orthogonal spaces and decode the information of each user without any Interference from the other user.

One of the common challenges in wireless communications networks is wiretapping broadcast signals from radio stations by eavesdroppers. In this paper is shown that Interference alignment (IA) technique can be completely eliminated intra and inter-cell Interferences, in a cellular communications network with the same frequency allocation to all of the users. Also, this technique is able to provide maximum degrees of freedom (DoF) and securing the communication against eavesdropping. IA approximately can close the rate of network secrecy to rate region of the interfering broadcast channel (IFBC) in high SNR regime. In order to prove the mathematical and intuitive capability of the Interference alignment technique in increasing communication security, a kind of IA algorithm closed-form is used in the downlink of an unsecured cellular network. Simulation results are demonstrated for a certain range from the number of eavesdropper’s receive antennas, that secrecy rate well possible come close to the network sum-capacity in high SNRs.

Interference alignment (IA) with Alamouti coding is an innovative method to increase the multiplexing gain and the diversity gain, simultaneously, in wireless Multiple-Input Multiple-Output (MIMO) systems. The main limitation of this method is requiring Perfect Channel State Information (CSI) to perform the beamforming on transmitters and receivers signals. Contrary to the acceptable performance of Alamouti coding in perfect CSI conditions, its efficiency is severely reduced in imperfect CSI conditions. In order to overcome this shortcoming, this paper discusses about the effect of imperfect CSI on a two user MIMO X-channel which uses Interference alignment together with Alamouti coding. Also, a closed form solution is extracted for the received signal in an imperfect CSI scenario. Our analysis shows that when the variance of the CSI error is increased, the Bit Error Rate (BER) of system increases linearly. Also, we propose a joint Power Allocation (PA) and constellation rotation algorithm to improve the performance of system in an imperfect CSI scenario. Computer simulations show a desirable improvement in BER by using PA, constellation rotation and joint of them.

Introduction: In the current research, it has been tried to qualitatively study all kinds of policies and measures necessary for alignment between teacher preparation programs and democratic social education competencies under the model of teacher education curricula, which include: direct (official) curriculum, Indirect curriculum, informal curriculum (implicit) and unstructured curriculum (hidden) should be identified in the educational system. Method: Qualitative approach and phenomenological method were used in this research. The field of research is Farhangian University of Hormozgan and the participants are  13  lecturers of this university. The sampling method is a combination of convenience and snowball sampling. The research tool was a semi-structured interview. The information was analyzed using thematic analysis method and then using MAXQDA software... Result: The information was analyzed using the theme analysis method and then using MAXQDA software in the form of 2  overarching themes, 8 organizing themes and 25  basic themes. The results of this research showed the basic policies and measures for teacher preparation programs, in the form of two components, strategies and solutions of teacher training curricula, separated by curricula (formal, informal, informal, unstructured curriculum) and with the goal of preparing The formation of teachers has been identified in the educational system to realize the competencies of democratic social education. Conclusion: Therefore, examining the opportunities, facilities, and resources available to achieve these actions should be on the agenda of decision makers and educational planners. It is necessary to pay special attention to the strategies and solutions of teacher training curricula.

One of the most important organizational challenges is the strategic alignment between information technology (IT) and business objectives. Organizations have deployed different approaches to achieve strategic alignment and competitive advantage. Enterprise architecture (EA) has been viewed as an effective approach not only for optimum management of IT, but also for strategic alignment of IT applications and business needs. EA maturity indicates the degree of attaining EA project goals, out of which, is the IT-Business alignment. In this paper, the relationship between enterprise architecture maturity (EAM) and strategic alignment maturity model (SAMM) has been investigated to declare whether EAM can act as enabler for SAMM. Research population includes enterprises in which, the EA project is implemented. Pearson’s correlation and regression test have been used for analyzing the data gathered by questionnaire. The findings indicate that the success of EA significantly influences strategic alignment maturity.

In this paper, a step-by-step laboratory procedure for performing a satellite's payload’s alignment measurement is presented. Four highly accurate theodolites are used along with two or more alignment corner cube to accurately extract the final attitude. Theodolites are arranged around the satellite in such a way that they have a clear direct view of the alignment cubes mounted on the payload and the satellite. Two theodolites should point to the payload’s alignment cube and the other two theodolites must point to the satellite’s alignment cube. Each theodolite must see at least one other theodolite, directly. Finally, by forming the coordinates systems of the payload and satellite in the theodolites coordinate system along with using the coordinate transfer matrices, the payload alignment correction matrix will be extracted in detail. The total method accuracy is within the order of few arcseconds.