scholarly journals V2X Communication System With Non-Orthogonal Multiple Access: Outage Performance Perspective

2021 ◽  
Vol 21 (2) ◽  
pp. 854
Author(s):  
Tu-Trinh Nguyen ◽  
Dinh-Thuan Do
Keyword(s):  
Multiple Access ◽  
High Reliability ◽  
Spectrum Efficiency ◽  
Full Duplex ◽  
Low Latency ◽  
Amplify And Forward ◽  
The Poor ◽  
Term Evolution

<span class="fontstyle0">To achieve low-latency and high-reliability (LLHR) for applications in the vehicle-toeverything (V2X) networks, the non-orthogonal multiple access (NOMA) based Long Term Evolution (LTE)-based is introduced a promising technology. NOMA-V2X provides higher spectrum efficiency compared with the orthogonal multiple access (OMA) based V2X. This study propose two-way relay assisted NOMA-V2X transmission by exploiting amplify-and-forward (AF) and full-duplex. We derive expressions of outage probability to evaluate performance of two vehicles and to improve the quality of service (QoS) for the device with the poor channel conditions. These expressions are further verified by Monte-Carlo simulations.</span> <br /><br />

scholarly journals Long-Term Evolution of Quality of Life and Symptoms Following Surgical Treatment for Endometriosis: Different Trajectories for Which Patients?

2020 ◽  
Vol 9 (8) ◽  
pp. 2461
Author(s):  
Aurélie Comptour ◽  
Céline Lambert ◽  
Pauline Chauvet ◽  
Claire Figuier ◽  
Anne-Sophie Gremeau ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Surgical Treatment ◽  
Short Form ◽  
Complete Information ◽  
Long Term Evolution ◽  
Epidemiological Methods ◽  
Multicenter Cohort Study ◽  
Term Evolution

Many studies have shown a global efficacy of laparoscopic surgery for patients with endometriosis in reducing painful symptoms and improving quality of life (QoL) in the short and long-term. The aim of this study was to analyze the different trajectories of long-term evolution in QoL and symptoms following surgical treatment for endometriosis, and to identify corresponding patient profiles. This prospective and multicenter cohort study concerned 962 patients who underwent laparoscopic treatment for endometriosis. QoL was evaluated using the Short Form (SF)-36 questionnaire and intensity of pain was reported using a visual analog scale prior to surgery and at 6, 12, 18, 24 and 36 months after surgery. Distinctive trajectories of pain and QoL evolution were identified using group-based trajectory modeling, an approach which gathers individuals into meaningful subgroups with statistically similar trajectories. Pelvic symptom trajectories (models of the evolution of dysmenorrhea, dyspareunia and chronic pelvic pain intensity over years) correspond to (1) patients with no pain or pain no longer after surgery, (2) patients with the biggest improvement in pain and (3) patients with continued severe pain after surgery. Our study reveals clear trajectories for the progression of symptoms and QoL after surgery that correspond to clusters of patients. This information may serve to complete information obtained from epidemiological methods currently used in selecting patients eligible for surgery.

Virtual Prototyping Simulation of Flexible Multi-Point Auxiliary Support Fixture for Blade Machining

2014 ◽  
Vol 496-500 ◽  
pp. 1256-1259 ◽  
Author(s):  
Yan Cao ◽  
Jing Li ◽  
Jian Hui Tian ◽  
Qing Ming Fan
Keyword(s):  
Cutting Force ◽  
High Reliability ◽  
Virtual Prototyping ◽  
Light Weight ◽  
Machining Quality ◽  
The Poor ◽  
Blade Machining ◽  
Thin Walled ◽  
Processing Difficulty

Spatial curved blades have been widely used in major aerospace manufacturers due to their light weight, high structural efficiency, high reliability, etc. However, their processing deformation, processing difficulty, and so on limit their use. In order to deal with the situation, flexible multi-point auxiliary supporting fixture for the processing of spatial curved thin-walled parts has become a major topic of current researches. The layout of positioning and clamping points of the flexible multi-point fixture direct affects the stiffness of clamping positions on the thin-walled parts to be processed. When cutting force is definite at a certain point in machining, the greater the stiffness at the processing positions on the part, the smaller the processing deformation due to the cutting force. Therefore, in order to reduce the machining deformation due to the poor stiffness, a suitable positioning and clamping layout is needed to improve the surface stiffness at the machining positions. Thus, the machining quality of thin-walled parts can be improved.

scholarly journals High Speed Mobility Management Performance in a Real LTE Scenario

2020 ◽  
Vol 10 (1) ◽  
pp. 5175-5179
Author(s):  
A. A. M. K. Abuelgasim ◽  
K. M. Yusof
Keyword(s):  
High Risk ◽  
Mobility Management ◽  
High Speed ◽  
Field Measurements ◽  
Mobile Operator ◽  
Seamless Connectivity ◽  
Term Evolution ◽  
Network Technologies

This paper discusses the mobility management for high-speed users, which is a crucial challenge for all mobile operators, especially when users are moving vertically across different network technologies. Mobility, also known as seamless connectivity, is directly influencing the quality of service (QoS). Mobility management-Handover (HO) performance was evaluated by field measurements of a Long Term Evolution (LTE) network of a mobile operator in the Middle East. Drive test measurements were used to analyze the results of different high-speed scenarios. User Equipment (UE) with high speed of 80-140km/h causes a high risk of failure of seamless connectivity as the HO procedure timing is longer than for UE with smaller speed. HO failure and call drop may occur when UE is moving with high speed across two adjacent cells in highways. During measurements, HO failure occurred when UE speed was 140km/h, and HO preparation timing increased when UE speed increased.

scholarly journals A new look on CSI imperfection in downlink NOMA systems

2021 ◽  
Vol 10 (3) ◽  
pp. 1415-1422
Author(s):  
Anh-Tu Le ◽  
Dinh-Thuan Do
Keyword(s):  
Monte Carlo ◽  
Performance Analysis ◽  
System Performance ◽  
Multiple Access ◽  
Spectrum Efficiency ◽  
System Model ◽  
Full Duplex ◽  
Channel State ◽  
State Information ◽  
Cooperative Scheme

Observing that cooperative scheme benefits to non-orthogonal multiple access (NOMA) systems, we focus on system performance analysis of downlink. However, spectrum efficiency is still high priority to be addressed in existing systems and hence this paper presents full-duplex enabling in NOMA systems. Other challenge needs be considered related to channel state information (CSI). In particular, we derive closedform expressions of outage probability for such NOMA systems under the presence of CSI imperfection. Furthermore, to fully exploit practical environment, we provide system model associated with Nakagami-m fading. The Monte-Carlo simulations are conducted to verify the exactness of considered systems.

scholarly journals ANALISA KELAYAKAN BISNIS STARONE DAN REKOMENDASI TEKNOLOGI ALTERNATIF

Jurnal Teknik ◽  
2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Muhamad Imron
Keyword(s):  
Balanced Scorecard ◽  
Code Division Multiple Access ◽  
Multiple Access ◽  
Gap Analysis ◽  
Performance Indicator ◽  
Key Performance Indicator ◽  
Term Evolution ◽  
Wireless Broadband ◽  
Code Division Multiple

Dalam perjalanannya teknologi telekomunikasi berbasis Code Division Multiple Acces (CDMA) adalah teknologi telepon seluler yang sudah ada di dunia hampir 20 tahun lebih. Setiap kali ada penantangnya dari teknologi Global System fo Mobile Communication (GSM), teknologi CDMA selalu berhasil menandinginya.  Teknologi CDMA  yang berawal  di Amerika  Serikat  ini telah dicermati selalu  mengimbangi perkembangan teknologi GSM . Pada saat itu GSM pertama muncul dan mengancam, teknologi CDMA dikembangkan menjadi CDMA 1X sebagai jawaban terhadap ancaman GSM. Kemudian ketika operator GSM meluncurkan GSM/EDGE, sekali lagi CDMA dikembangkan menjadi teknologi CDMA Evolution-Data Optimized (CDMA/EV-DO).  Tetapi  dengan  munculnya  3G-UMTS  dan  HSDPA,  kemudian dengan adanya rencana LTE (Long Term Evolution dari kamp GSM) dan WiMax dari dunia wireless broadband, kebanyakan operator dan carrier di Amerika Serikat enggan mendukung perkembangan teknologi CDMA lebih lanjut. Melihat perkembangan teknologi CDMA di dunia yang demikian tentu saja sedikit banyak mempengaruhi perkembangan CDMA di Indonesia tidak terkecuali PT. Indosat Tbk. dengan brand Starone yang sudah berlangsung hampir 10 tahun sejak kemunculannya pada tahun2004. Melihat bisnis CDMA ke depan khususnya Starone perlu dilakukan penelitian yang  dapat  menggambarkan  kelanjutan  bisnis  ini  bisa  dikembangkan  atau  tidak.Dengan pendekatan teori Balanced Scorecard dan Gap Analysis serta melihat profil keuangan yang mempunyai kecenderungan revenue yang menurun secara drastis,  darisisi pelanggan jumlah pelanggan aktif semakin hari semakin menurun, bisnis proses internal yang tidak memasukkan Key Performance Indicator (KPI)  sebagai tolok ukurutama dalam kinerja operasional serta pertumbuhan dan pembelajaran dari Starone ini dapat disimpulkan bahwa bisnis ini secara kontinuitas tidak dapat dilanjutkan lagi. Selanjutnya dicarikan jalan keluar bagi pelanggan yang masih berada pada layananStarone untuk menggunakan teknologi lain sehingga layanan komunikasi masih bisa dirasakan oleh pelanggan.Kata  Kunci:  Code  Division  Multiple  Access,  Strategy,  Balanced  Scorecard,  Key Performance Indicato,Gap Analysis

scholarly journals Performance analysis of a novel method for fast handovers in TDD and FDD for long term evolution

2018 ◽  
Vol 7 (1.9) ◽  
pp. 115
Author(s):  
G K.Venkatesh ◽  
P V.Rao
Keyword(s):  
Mobile Network ◽  
Wireless Channel ◽  
Access Time ◽  
Wireless Link ◽  
Time Division Duplex ◽  
Handover Delay ◽  
Term Evolution ◽  
Time Division

The LTE Long Term Evolution highly developed Technology, Handover is the essential function of the mobility of user in cellular networks in Time Division Duplex as well as Frequency Division Duplex. Handover is one of the essential that can affect the [QoS] Quality of Service with Capacity of Mobile Broadband Networks. Within mobile cellular network communication systems, a (spectrum) limited shared resource needs to be shared with all the users, so full duplex communication is achieved. This paper involves studying diverse Hand over delay parameters and also focus on reducing “Hard Handover delay” by minimizing interruption time, activation time, wireless channel accesses time as well as the wireless link transmission delay. Technique is developed in order to reduce the handover delay time in Time Division Duplex network which too reduces the wireless channel access time and the wireless link transmission delay. A novel handover algorithm is developed which would decreases the handover delay time and access time inside mobile network environment.Additional work may be conceded on to obtain enhanced performance and Quality of service in Time Division Duplex mobile network.

Sign in / Sign up

Export Citation Format

Share Document