Adly S. Tag Eldien

FastSLAM 2.0 tracking and mapping as a Cloud Robotics service

Abstract The Simultaneous Localization and Mapping (SLAM) by an autonomous robot is an intensive computational problem and is considered to be a time consuming process. A major limitation of the pose tracking is the real-time constraint. The pose estimation should be done at an acceptable latency to get accurate position information. In this paper, FastSLAM 2.0 approach is proposed, where the computational process is divided into two parallel tasks, the pose tracking and the map optimization. The presented work depends on a distributed architecture where the tracking and mapping tasks concurrently operate as a service in the Cloud. Therefore, the robot onboard system is freed from all the heavy computations. The experiments are performed on public dataset comparable to state-of-the-art techniques. The results show that the computational cost of the tracking process in the Cloud is reduced by 83.6% as compared to its execution on a single robot platform.

A novel vision to mitigate pilot contamination in massive MIMO-based 5G networks

Massive multiple-input multiple-output (MIMO) is one of the promising technologies to be used in the future fifth generation (5G) wireless networks for its capability to increase the system throughput, improve spectral efficiency and energy efficiency. To achieve these benefits of the massive MIMO, there are many challenges that need to be handled. One of these challenges is the pilot contamination problem that arises from reusing pilot sequences among the system cells. Since this problem is considered as a bottleneck of the system performance, it attracted many researchers who proposed schemes to solve it. In this paper, we propose a new scheme that mitigates its effect by adopting both asynchronous pilot transmission (APT) and fractional pilot reuse (FPR). We compare the performance of our proposed scheme with other schemes using computer simulations and show that our proposed scheme enhances the performance of the time division duplex (TDD) multi-cell massive MIMO systems in terms of the signal to interference and noise ratio (SINR) and capacity.

Combined Space-time-frequency codes for four time slots with beamforming

Multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) system has been implemented to achieve a good service and boost the data rate in wireless communication system. Space Time Frequency (STF) is used to enhance the diversity gain. This paper aims at a performance analysis of MIMO-OFDM system using two different STF codes with a random beamforming. The two proposed codes give better bit error rates (BER) performance as compared to the BER performance of STF of Alamouti code for MIMO-OFDM system. We have applied STF with random beamforming to improve the performance of the whole system for different diversity. The performance of the second STFC is better than the performance of the first STFC at high signal to noise ratio (SNR). It is also observed that the BER performance of the two proposed schemes with beamforming is better than the BER performance of space-time block codes (STBC) with beamforming.

An efficient distributed approach for key management in microgrids

Smart grid (SG) is a new technology which allows the electrical power grid to be smart. Cyber security plays an essential role in the smart grid in order to secure the bidirectional communication between the utility and the consumer side. To pursue confidentiality and integrity, a key management scheme is considered a critical challenge in the SG. As a result, several key management protocols have been proposed in literature. However, many of those proposed protocols have a centralized feature that depends on a single server called Meter Data Management System (MDMS) to distribute keys and update them. In this paper, we propose a distributed key management scheme with authentication capability to avoid the single-point failure problem by removing the need for using an MDMS. Furthermore, we apply our scheme to the microgrid which can be considered a small-scale smart grid and can be isolated from the main grid. The security and performance analysis are conducted to show the effectiveness and scalability of our scheme by considering the communication and computation cost.

Proposed QoS-guarantee cross-layer algorithm over MIMO-LTE downlink system

To achieve the target data rate of Long Term Evolution (LTE), many new techniques are necessary. Multiple-Input Multiple-Output (MIMO) is one key technique among them due to its ability to enhance the radio channel capacity of cellular systems without extra spectrum cost. Cross-layer has been thought as one of the most efficient ways for multimedia communications over wireless networks. In this paper a proposed cross-layer approaches to solve the problem of switching between MIMO multiplexing and diversity modes. We used Matlab Simulator to impose the LTE MIMO constraint of selecting only one MIMO mode per user per transmission time interval (TTI). The results show that, the proposed adaptive method achieves the Quality of Service (QoS) guarantees for the Guaranteed Bit Rate (GBR) traffic.