We address the throughput maximization problem for downlink transmission in DF-RELAY-assisted cognitive radio networks (CRNs) based on simultaneous wireless information and power transfer (SWIPT) capability. In this envisioned network, multiple-input multiple-output (MIMO) RELAY and secondary user (SU) equipment are designed to handle both radio frequency (RF) signal energy harvesting and SWIPT functional tasks. Additionally, the cognitive base station (CBS) communicates with the SU only via the MIMO RELAY. Based on the considered network model, several combined constraints of the main problem complicate the solution. Therefore, in this paper, we apply heuristic guidelines within the convex optimization framework to handle this complexity. First, consider the problem of maximizing throughput on both sides of the RELAY separately. Second, each side progresses to solve the complex problem optimally by adopting strategies for solving sub-problems. Finally, these optimal solutions are synthesized by proposing a heuristic iterative power allocation algorithm that satisfies the combinatorial constraints with short convergence times. The performance of the optimal proposed algorithm (OPA) is evaluated against benchmark algorithms via numerical results on optimality, convergence time, constraints’ compliance, and imperfect channel state information (CSI) on the CBS-PU link.

In this study, we introduce a new two-way RELAY channel and obtain an inner bound and an outer bound for the discrete and memoryless multiple access RELAY channels with receiver-source feedback via two-way RELAY channel in which end nodes exchange signals by a RELAY node. And we extend these results to the Gaussian case. By numerical computing, we show that our inner bound is the same with one obtained by Hou-Koetter-Kramer, for the channel with RELAY-source feedback.

Anti-lock braking system (ABS) is an automobile safety system that allows the wheels on a motor vehicle to maintain tractive contact with the road surface according to driver inputs. It is reported that this system can be considered as one of the most important options in vehicle safety and consequently, concentration upon this system can be extremely useful. In conventional anti-lock braking systems, the braking force is generated by hydraulic pressure and then is applied to the driven wheels through hydraulic circuits. Whereas, the fundamental of braking force generation in EMABS is thoroughly different. In this paper, basic concepts of ELECTROMAGNETIC anti-lock braking system are introduced and some of its important advantages in comparison with conventional anti-lock braking systems are presented. In EMABS, a portion of braking force is generated by using an ELECTROMAGNETIC RELAY and is transmitted into braking shoes through hydraulic circuits. It should be noted that the initial pressure of braking force in EMABS is also generated by a hydraulic booster and it causes the locking of driven wheels. Afterward, the performance of ELECTROMAGNETIC anti-lock system will be started and the locked wheel will be released.

Minimization of the discrimination time between the backup and main overcurrent RELAY is one of the most critical issue in RELAY coordination of power system. Determination of time setting multipliers (TSMs) using evolutionary algorithms has been studied in previous papers. In this paper, TSM, various characteristics of the overcurrent RELAYs and pickup currents are simultaneously considered to improve coordination of main and backup overcurrent RELAYs. Furthermore, the coordination problem can also be considered as an optimization problem which can be solved using artificial intelligent methods. Recently, a novel optimization algorithm, called hyper-sphere search (HSS) algorithm, has been introduced. In this paper, Improved HSS (IHSS) is introduced. Based on the problems mentioned in this paper, the IHSS algorithm is more appropriate for obtaining the characteristics of the overcurrent RELAYs, pickup currents and their TSMs. The result of IHSS is compared with HSS algorithm which has been used in previous studies. The simulation results on the test network show the efficiency of using IHSS and considering pickup currents in term of better RELAYs coordination.

The electrical behavior of neurons can be more complex in the presence of autapse. In the presence of an autaptic connection, the Izhikevich neuron model can show a variety of dynamic behaviors, such as chaotic behavior. This paper presents a novel, high speed and robust pseudo random number generator based on the autaptic Izhikevich neuron oscillator and its FPGA implementation. The autaptic Izhikevich neuron model is simulated and dynamically analyzed. Then, the proposed pseudo-random number generator is modeled and simulated using the Xilinx system generator platform, synthesized using Xilinx Synthesis Tool, and implemented on the XILINX SPARTAN-6 XC6SLX9 FPGA evaluation board. As a post processing operation, the XOR function is used to increase the randomness of the output bit sequences. The FPGA implementation results show that the implementation cost of the proposed pseudo-random number generator is lower than similar works, and the proposed generator achieves a maximum frequency of 63.2 MHz. The NIST test suite is used for testing the quality of the generated bit sequences. The NIST test results indicates the high quality of the generated random bit sequence.

The In-Band Full-Duplex (IBFD) technique is attracting a great deal of attention thanks to its ability to simultaneously transmit and receive the information over the same frequency band. IBFD has the potential to double the spectral efficiency and system capacity, compared to conventional Half-Duplex (HD) schemes. However, strong self-interference caused by simultaneous transmission and receiption over the same frequency band, renders the feasibility of IBFD in practice. Recently, advanced self-interference cancellation techniques are proposed to address this issue. In this paper, an IBFD RELAY network with Simultaneous Wireless Information and Power Transmission (SWIPT) is introduced that applies multiple RELAYs. We propose a joint antenna-and-RELAY selection scheme that decreases the complexity and increases the ergodic capacity. We provide simulation results for the outage probability and the ergodic capacity. The results show that the IBFD system outperforms the HD system, for a certain range of self-interference power.

Spatial diversity is one of the most effective techniques to combat fading in wireless channels that can be implemented through antenna arrays. In this paper the hybrid decode-amplify-forward protocol with best RELAY selection (HDAF-S)in a cooperative system with multiple parallel RELAYs with independent non-identically channels is considered and tight upper and lower bounds on bit error rate (BER) of this protocol is derived. It is shown that the BER of this protocol outperforms the BER of amplify and forward (AF) protocol but cannot exceeds the performance of decode and forward (DF) protocol. Then through asymptotic analysis for high SNR regime, it is shown that the HDAF-S protocol achieves full diversity order. Then the BER performance of HDAF protocol with n-th best RELAY selection (HDAF-nS) in independent and identically distributed channels is analyzed and tight upper and lower bounds on the BER are derived. Asymptotic analysis shows that this protocol cannot achieve full diversity order and it is shown that the diversity order decreases as n increases. The analytical results are validated through simulations.

The Polar coding is a method which have been proposed by Arikan and it is one of the first codes that achieve the capacity for vast numerous channels. This paper discusses RELAY channel polarization in order to achieve the capacity and it has been shown that polarization of two RELAY channels can be given a more achievable rate region in the general form. This method is compatible with the original vision of polarization based on the combining, splitting and polarizing of channels and it has been shown that the complexity of encoding and decoding for these codes in mentioned method are O(N log N), and also error probability for them is O(2-(N)b). Choose the best sub-channels in polarized RELAY channels for sending data is a big trouble in this structure. In this paper, we have been presented a new scheme for choosing a good index for sending the information bits in RELAY channels polarized in order to have the best performance by using sending information bits over FIF sets.

The present study on politeness is an attempt to examine (dis)agreeing strategies utilized by EFL learners while chatting on the internet. Subjects of the study were forty male and thirty-three female Iranian natives whose internet RELAY chat (IRC) interactions, composed of 400 excerpts, were collected between December 2007 and September 2008. Data analysis was based on the general taxonomy of politeness strategies suggested by Brown and Levinson (1987) which is the baseline of many politeness studies today. The results indicate that IRC is a mode of communication whose characteristics are typically different from face-to-face and real-life conversational settings. Some common face threatening acts (FTAs) like ‘direct disagreements’ are performed widely in chat channels. Furthermore, gender-oriented differences were found not to be statistically significant on the internet.