51 research outputs found

    UFMC and f-OFDM: Contender Waveforms of 5G Wireless Communication System

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    Because of the increased demand for high data rates, looking for using new technologies that meet these requirements are considered a necessary. Hence, Fifth Generation (5G) is expected to be impressive in offering these requirements and implement around 2020. Orthogonal Frequency Division Multiplexing (OFDM) is considered a main technology of LTE wireless communication standards. Due to its suffering from high Bit Error Rate (BER) and Peak Average Power Ratio (PAPR), OFDM doesn't consider as charming solution for future wireless communications and several emerging applications of 5G. Moreover, high Out of Band Emission (OOBE) and inability of supporting the flexible numerology are other demerits of OFDM systems. Thus, looking for alternative waveforms which have the ability of solving OFDM disadvantages are necessary to introduce it as contender candidate for 5G wireless communication systems. In this paper, both of Filtered-OFDM (f-OFDM) and Universal Filtered Multi carrier (UFMC) systems have been discussed for 5G wireless communication systems and compared to OFDM system. The results showed that f-OFDM system is better than both OFDM and UFMC systems and could be introducing as competitive candidate for 5G wireless communication systems because of its ability of reducing OOBE and enhancing BER performance

    Design and development of handover simulator model in 5G cellular network

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    In the modern era of technology, the high speed internet is the most important part of human life. The current available network is reckoned to be slow in speed and not be up to snuff for data transmission regarding business applications. The objective of handover mechanism is to reassign the current session handle by internet gadget. The globe needs the next generation high mobility and throughput performance based internet model. This research paper explains the proposed method of design and development for handover based 5G cellular network. In comparison to the traditional method, we propose to control the handovers between base-stations using a concentric method. The channel simulator is applied over the range of the frequencies from 500 MHz to 150 GHz and radio frequency for the 700 MHz bandwidth. The performance of the simulation system is calculated on the basis of handover preparation and completion time regarding base station as well as number of users. From this experiment we achieve the 7.08 ms handover preparation time and 9.98 ms handover completion time. The author recommended the minimum handover completion time, perform the high speed for 5G cellular networks

    Downlink LTE System Performance Improvement by Using BCH Codes over LTE-MIMO Channel

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    Long-term Evolution (LTE) has potential feasibility to implement high-speed data transmission. This technology is essential for accommodating the rising utilization of data and voice service. Nonetheless, the main problem is the deteriorated performance of wireless communication systems following the elevation in bit error rate (BER) owing to multipath fading environments. Therefore, using channel coding is essential to reduce BER, which leads to enhancement of system performance of digital communication systems. Previous studies have reported utilization of channel codes including turbo and convolutional codes in LTE systems for attaining error control system. As such, the key challenge of selecting category of coding method is the trade-off between elevating decoding complexity and enhancing system performance. Hence, the study herein proposed Bose and Chaudhuri (BCH) codes as channel coding for downlink LTE system over MIMO channel. This is aimed to attain an adaptive error control with low complexity compared to turbo and convolutional codes. The findings indicated that BCH codes had reduced BER compared to turbo and convolutional codes in both quadrature phase-shift keying (QPSK) modulation schemes and binary phase-shift keying (BPSK) with regard to the downlink LTE system performance. The suggested method had approximately 4dB coding gain at 1X10-1 against both of convolutional and turbo codes in BPSK. While, for QPSK, the proposed method had approximately 5dB and 6dB compared to turbo and convolutional codes, respectively. Nonetheless, enhanced performance of the suggested system was observed through reducing BER of the received data by adding the number of antennas in MIMO channel

    RS Codes for Downlink LTE System over LTE-MIMO Channel

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    Nowdays, different applications require a modern generation of mobile communication systems; long term evolution (LTE) is a candidate to achieve this purpose. One important challenge in wireless communications, including LTE systems, is the suitable techniques of controlling errors that degrade system performance in transmission systems over multipath fading channels. Different forward Error correction (FEC) techniqes are required to improve the robustness of transmission channels. In this paper, Reed-Solomon (RS) codes were used with a downlink LTE system over a LTE-MIMO channel. This research contributes by combining RS codes that have low decoding complexity (by using hard decision decoding) with a LTE-MIMO channel to improve downlink LTE system performance. The results show that using RS codes clearly improves LTE system performance and thus decreases Bit Error Rates (BER) more than convolutional and turbo codes which have high decoding complexity. Lastly, the results show also extra improvements of downlink LTE system performance by increasing the number of antennas of the LTE-MIMO channel

    Comparative evaluation QoS of FTP over LEO and GEO Satellite Networks with diffserv architecture

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    This paper presents studies of the end-to-end QoS of IP over integrated terrestrial and NGSN (next generation satellite network) for file transfer service using FTP. The authors compare between LEO and GEO satellites constellations for the QoS parameters (i.e., delay, jitter, loss rate and throughput) of file transfer between one server in London and a client in Boston. The authors model the file transfer with multiple connections and file size variation according to exponential and Pareto distributions respectively. The authors create the scenario with error model to simulate transmission loss environment using the NS-2 simulation software. A Diffserv (differentiated services) queue interface is placed in the server side to regulate the traffic flows across the narrow bandwidth of the satellite links. The authors compare the empirical TCP throughput traces with analytical model for validation. The results showed the performance evaluation and presented a good comparison of the QoS parameters involved in the data transfer across LEO and GEO satellites systems

    QoS based Admission Control using Multipath Scheduler for IP over Satellite Networks

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    This paper presents a novel scheduling algorithm to support quality of service (QoS) for multiservice applications over integrated satellite and terrestrial networks using admission control system with multipath selection capabilities. The algorithm exploits the multipath routing paradigm over LEO and GEO satellites constellation in order to achieve optimum end-to-end QoS of the client-server Internet architecture for HTTP web service, file transfer, video streaming and VoIP applications. The proposed multipath scheduler over the satellite networks advocates load balancing technique based on optimum time-bandwidth in order to accommodate the burst of application traffics. The method tries to balance the bandwidth load and queue length on each link over satellite in order to fulfil the optimum QoS level for each traffic type. Each connection of a traffic type will be routed over a link with the least bandwidth load and queue length at current time in order to avoid congestion state. The multipath routing scheduling decision is based on per connection granularity so that packet reordering at the receiver side could be avoided. The performance evaluation of IP over satellites has been carried out using multiple connections, different file sizes and bit-error-rate (BER) variations to measure the packet delay, loss ratio and throughput

    Performance of Non-Uniform Duty-Cycled ContikiMAC in Wireless Sensor Networks

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    Wireless Sensor Network (WSN) is a promising technology in Internet of Things (IoTs) because it can be implemented in many applications. However, a main drawback of WSN is it has limited energy because each sensor node is powered using batteries. Therefore, duty-cycle mechanisms are introduced to reduce power consumption of the sensor nodes by ensuring the sensor nodes in the sleep mode almost of the time in order to prolong the network lifetime. One of the de-facto standard of duty-cycle mechanism in WSN is ContikiMAC, which is the default duty-cycle mechanism in Contiki OS. ContikiMAC ensures nodes can participate in network communication yet keep it in sleep mode for roughly 99\% of the time. However, it is found that the ContikiMAC does not perform well in dynamic network conditions. In a bursty network, ContikiMAC provides a poor performance in term of packet delivery ratio, which is caused by congestion. One possible solution is ContikiMAC should increase its duty-cycle rate in order to support the bursty traffic. This solution creates a non-uniform duty-cycle rates among the sensor nodes in the network. This work aims to investigate the effect of non-uniform duty-cycle rates on the performance on ContikiMAC. Cooja simulator is selected as the simulation tool. Three different simulation scenarios are considered depending on the Clear Channel Assessment Rate (CCR) configurations: a low uniform CCR value (Low-CCR), a high uniform CCR value (High-CCR) and non-uniform CCR values (Non-uniform-CCR). The simulation results show that the Low-CCR scenario provides the worst performance of PDR. On the other hand, the High-CCR scenario provides the best performance of PDR. The Non-uniform-CCR provides PDR in between of Low-CCR and High-CCR

    QoS Simulation and analysis of HTTP over LEO satellite constellation

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    In this paper, we present an end-to-end QoS simulation studies on internetworking of remote LAN and long range communications over LEO-Iridium satellites constellation taking SuperJARING network in Malaysia as an example. A macro level network simulation scenario based on actual network topology in Malaysia is implemented as Diffserv network model using the network simulator-2 (NS-2). Web traffic (HTTP) is used as the internet traffic models in the simulation analysis. All simulations are carried out in error-free and link-loss environment. In error-free simulations, the accumulative network traffic loads are varied from 20%, 50% and 80% while in link�loss environment simulations only 20% traffic load is used with bit error rate (BER) varied from 1x10-5 , 1x10-4 and 2x10-4 . We compare the empirical TCP throughput traces with analytical model for validation. The results show clearly that QoS can be achieved with IP Diffserv over satellites constellation like Iridium

    VANET-Based Traffic Monitoring and Incident Detection System: A Review

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    As a component of intelligent transport systems (ITS), vehicular ad hoc network (VANET), which is a subform of manet, has been identified. It is established on the roads based on available vehicles and supporting road infrastructure, such as base stations. An accident can be defined as any activity in the environment that may be harmful to human life or dangerous to human life. In terms of early detection, and broadcast delay. VANET has shown various problems. The available technologies for incident detection and the corresponding algorithms for processing. The present problem and challenges of incident detection in VANET technology are discussed in this paper. The paper also reviews the recently proposed methods for early incident techniques and studies them

    Energy-Efficient Low-Complexity Algorithm in 5G Massive MIMO Systems

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    Energy efficiency (EE) is a critical design when taking into account circuit power consumption (CPC) in fifth-generation cellular networks. These problems arise because of the increasing number of antennas in massive multiple-input multiple-output (MIMO) systems, attributable to inter-cell interference for channel state information. Apart from that, a higher number of radio frequency (RF) chains at the base station and active users consume more power due to the processing activities in digital-to-analogue converters and power amplifiers. Therefore, antenna selection, user selection, optimal transmission power, and pilot reuse power are important aspects in improving energy efficiency in massive MIMO systems. This work aims to investigate joint antenna selection, optimal transmit power and joint user selection based on deriving the closed-form of the maximal EE, with complete knowledge of large-scale fading with maximum ratio transmission. It also accounts for channel estimation and eliminating pilot contamination as antennasM→∞. This formulates the optimization problem of joint optimal antenna selection, transmits power allocation and joint user selection to mitigate inter-cellinterference in downlink multi-cell massiveMIMO systems under minimized reuse of pilot sequences based on a novel iterative low-complexity algorithm (LCA) for Newton’s methods and Lagrange multipliers. To analyze the precise power consumption, a novel power consumption scheme is proposed for each individual antenna, based on the transmit power amplifier and CPC. Simulation results demonstrate that the maximal EE was achieved using the iterative LCA based on reasonable maximum transmit power, in the case the noise power is less than the received power pilot. The maximum EE was achieved with the desired maximum transmit power threshold by minimizing pilot reuse, in the case the transmit power allocation ρd = 40 dBm, and the optimal EE=71.232 Mb/j
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