17,292 research outputs found

    Optimization of automatically generated multi-core code for the LTE RACH-PD algorithm

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    Embedded real-time applications in communication systems require high processing power. Manual scheduling devel-oped for single-processor applications is not suited to multi-core architectures. The Algorithm Architecture Matching (AAM) methodology optimizes static application implementation on multi-core architectures. The Random Access Channel Preamble Detection (RACH-PD) is an algorithm for non-synchronized access of Long Term Evolu-tion (LTE) wireless networks. LTE aims to improve the spectral efficiency of the next generation cellular system. This paper de-scribes a complete methodology for implementing the RACH-PD. AAM prototyping is applied to the RACH-PD which is modelled as a Synchronous DataFlow graph (SDF). An efficient implemen-tation of the algorithm onto a multi-core DSP, the TI C6487, is then explained. Benchmarks for the solution are given

    GROUP BASED ALGORITHM TO MANAGE ACCESS TECHNIQUE IN THE VEHICULAR NETWORKING TO REDUCE PREAMBLE ID COLLISION AND IMPROVE RACH ALLOCATION IN ITS

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    ABSTRACT Intelligent transportation system (ITS) is an application which provides intelligence to the transportation and traffic management systems. Although the word ITS applies to all systems in the transportation but as per the European union directive it is the application of Information and communication technology in the field of transportation is defined as ITS. The communication technology has evolved greatly today from 2G/3G to long term evolution (LTE). In this paper we focus on the LTE and its application in the ITS. Since LTE offers excellent QoS, wide area coverage and high availability it is a preferred choice for vehicle to infrastructure (V2I) service. At the same time the LTE customer base is increasing day by day which results in congestion and accessing the network to send or request resources becomes difficult. In this paper we have proposed a group based node selection algorithm to reduce the preamble ID collision otherwise this uncoordinated preamble ID transmission by vehicle node (VN) will eventually clog the network and there will be a massive congestion and re-transmissions attempts by VNs to obtain the random access channel (RACH). KEYWORDS Intelligent transportation system (ITS), Long term evolution (LTE), Mobile ad hoc network (MANET), Vehicle ad hoc network (VANET), Vehicle to infrastructure (V2I), Vehicle to vehicle (V2V), Random access channel (RACH)

    LTE and Wi-Fi Coexistence in Unlicensed Spectrum with Application to Smart Grid: A Review

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    Long Term Evolution (LTE) is expanding its utilization in unlicensed band by deploying LTE Unlicensed (LTEU) and Licensed Assisted Access LTE (LTE-LAA) technology. Smart Grid can take the advantages of unlicensed bands for achieving two-way communication between smart meters and utility data centers by using LTE-U/LTE-LAA. However, both schemes must co-exist with the incumbent Wi-Fi system. In this paper, several co-existence schemes of Wi-Fi and LTE technology is comprehensively reviewed. The challenges of deploying LTE and Wi-Fi in the same band are clearly addressed based on the papers reviewed. Solution procedures and techniques to resolve the challenging issues are discussed in a short manner. The performance of various network architectures such as listenbefore- talk (LBT) based LTE, carrier sense multiple access with collision avoidance (CSMA/CA) based Wi-Fi is briefly compared. Finally, an attempt is made to implement these proposed LTEWi- Fi models in smart grid technology.Comment: submitted in 2018 IEEE PES T&

    Goodbye, ALOHA!

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    ©2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The vision of the Internet of Things (IoT) to interconnect and Internet-connect everyday people, objects, and machines poses new challenges in the design of wireless communication networks. The design of medium access control (MAC) protocols has been traditionally an intense area of research due to their high impact on the overall performance of wireless communications. The majority of research activities in this field deal with different variations of protocols somehow based on ALOHA, either with or without listen before talk, i.e., carrier sensing multiple access. These protocols operate well under low traffic loads and low number of simultaneous devices. However, they suffer from congestion as the traffic load and the number of devices increase. For this reason, unless revisited, the MAC layer can become a bottleneck for the success of the IoT. In this paper, we provide an overview of the existing MAC solutions for the IoT, describing current limitations and envisioned challenges for the near future. Motivated by those, we identify a family of simple algorithms based on distributed queueing (DQ), which can operate for an infinite number of devices generating any traffic load and pattern. A description of the DQ mechanism is provided and most relevant existing studies of DQ applied in different scenarios are described in this paper. In addition, we provide a novel performance evaluation of DQ when applied for the IoT. Finally, a description of the very first demo of DQ for its use in the IoT is also included in this paper.Peer ReviewedPostprint (author's final draft

    Partially Blind Handovers for mmWave New Radio Aided by Sub-6 GHz LTE Signaling

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    For a base station that supports cellular communications in sub-6 GHz LTE and millimeter (mmWave) bands, we propose a supervised machine learning algorithm to improve the success rate in the handover between the two radio frequencies using sub-6 GHz and mmWave prior channel measurements within a temporal window. The main contributions of our paper are to 1) introduce partially blind handovers, 2) employ machine learning to perform handover success predictions from sub-6 GHz to mmWave frequencies, and 3) show that this machine learning based algorithm combined with partially blind handovers can improve the handover success rate in a realistic network setup of colocated cells. Simulation results show improvement in handover success rates for our proposed algorithm compared to standard handover algorithms.Comment: (c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other work
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