Multicode CDMA for high-speed mobile communications

2002 ◽  
Author(s):  
Jun Chen
Keyword(s):  
Mobile Communications ◽  
High Speed ◽  
Multicode Cdma

scholarly journals Blockchain and Internet of Things in Higher Education.pdf

2020 ◽  
Author(s):  
Tanweer Alam ◽  
Mohamed Benaida
Keyword(s):  
Internet Of Things ◽  
Mobile Communications ◽  
High Speed ◽  
Wireless Networking ◽  
Research Area ◽  
The Internet ◽  
Web Pages ◽  
Main Research ◽  
Iot Platform ◽  
The Internet Of Things

Building the innovative blockchain-based architecture across the Internet of Things (IoT) platform for the education system could be an enticing mechanism to boost communication efficiency within the 5 G network. Wireless networking would have been the main research area allowing people to communicate without using the wires. It was established at the start of the Internet by retrieving the web pages to connect from one computer to another computer Moreover, high-speed, intelligent, powerful networks with numerous contemporary technologies, such as low power consumption, and so on, appear to be available in today's world to connect among each other. The extension of fog features on physical things under IoT is allowed in this situation. One of the complex tasks throughout the area of mobile communications would be to design a new virtualization framework based on blockchain across the Internet of Things architecture. The goal of this research is to connect a new study for an educational system that contains Blockchain to the internet of things or keeping things cryptographically secure on the internet. This research combines with its improved blockchain and IoT to create an efficient interaction system between students, teachers, employers, developers, facilitators and accreditors on the Internet. This specified framework is detailed research's great estimation.

High Speed Packet Access Broadband Mobile Communications

2009 ◽  
pp. 595-604
Author(s):  
Athanassios C. Iossifides ◽  
Spiros Louvros
Keyword(s):  
Mobile Communications ◽  
Rural Areas ◽  
High Speed ◽  
Data Transfer ◽  
Mobile Wimax ◽  
Major Step ◽  
Transfer Rates ◽  
Mobile Broadband ◽  
History Of ◽  
Broadband Market

Mobile broadband communications systems have already become a fact during the last few years. The evolution of 3G Universal Mobile Telecommunications Systems (UMTS) towards HSDPA/HSUPA systems have already posed a forceful solution for mobile broadband and multimedia services in the market, making a major step ahead of the main competitive technology, that is, WiMax systems based on IEEE 802.16 standard. According to the latest analyses (GSM Association, 2007; Little, 2007), while WiMax has gained considerable attention the last few years, HSPA is expected to dominate the mobile broadband market. The main reasons behind this forecast are: • HSPA is already active in a significant number of operators and is going to be established for the majority of mobile broadband networks worldwide over the next five years, while commercial WiMax systems are only making their first steps. • Mobile WiMax is a competitive technology for selection by operators in only a limited number of circumstances where conditions are favourable. Future mobile WiMax systems may potentially achieve higher data transfer rates than HSPA, though cell coverage for these rates is expected to be substantially smaller. In addition, WiMax technology is less capable in terms of voice traffic capacity, thus limiting market size and corresponding revenues. • In order to overcome the aforementioned disadvantages, WiMax commercial launches are expected to introduce a relative CAPEX disadvantage of at least 20–50% comparing to HSPA, in favorable cases, while there are indications of an increase by up to 5–10 times when accounting for rural areas deployments. The short commercial history of HSDPA (based on Rel.5 specifications of 3GPP) started in December of 2005 (first wide scale launch by Cingular Wireless, closely followed by Manx Telecom and Telekom Austria). Bite Lietuva (Lithuania) was the first operator that launched 3.6 Mbps. HSUPA was first demonstrated by Mobilkom Austria in November 2006 and soon launched commercially in Italia by 3 in December 2006. Mobilkom Austria launched the combination of HSDPA at 7.2 Mbps and HSUPA in February 2007. By September of 2007, less than two years after the first commercial launch, 141 operators in 65 countries (24 out of 27 in EU) have already gone commercial with HSDPA with 38 operators among them supporting a 3.6 Mbps downlink. In addition, devices supporting HSDPA/HSUPA services are rapidly enriched. 311 devices from 79 suppliers have already been available by September 2007, including handsets, data cards, USB modems, notebooks, wireless routers, and embedded modules (http://hspa.gsmworld.com).

Dedicated Mobile Communications for High-speed Railway

2018 ◽  
Author(s):  
Zhang-Dui Zhong ◽  
Bo Ai ◽  
Gang Zhu ◽  
Hao Wu ◽  
Lei Xiong ◽  
...  
Keyword(s):  
Mobile Communications ◽  
High Speed ◽  
High Speed Railway

Doppler Diversity Transmitter for OFDM Wireless Mobile Communications Based on Fixed Track

2012 ◽  
Vol 457-458 ◽  
pp. 940-947
Author(s):  
Jin Tang Wang ◽  
Lai Bo Zheng ◽  
Xin Feng Zhao ◽  
Ming Juan Huang ◽  
Jian Li Wang
Keyword(s):  
Mobile Communications ◽  
High Speed ◽  
Wireless Mobile Communications ◽  
Doppler Diversity ◽  
Channel Information ◽  
Wireless Mobile ◽  
Better Than

A Doppler diversity transmitter for OFDM high-speed mobile communications based on fixed track is proposed. Because of fixed track, we can get the channel information and branches’ weights in advance, utilize the channel information do pre-equalization for every branch in transmitter. After modulation, branch outputs are individually frequency shifted, weighted and added together. Extensive simulations show that the proposed transmitter alters the statistics of the fading to improve BER significantly and better than the Doppler diversity receiver’s performance.

scholarly journals Performance of Optical Mobile Communications with User Mobility and Multiple Light Sources

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Jian Dang ◽  
Jiajun Gao ◽  
Zaichen Zhang ◽  
Liang Wu ◽  
Bingcheng Zhu ◽  
...  
Keyword(s):  
Mobile Communications ◽  
High Speed ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
Light Sources ◽  
Optical Scheme ◽  
User Mobility ◽  
Optical Wireless ◽  
Free Space Optical ◽  
User Grouping

Optical mobile communication (OMC) is a recently proposed optical wireless communication concept aiming to provide very high-speed data rate optical wireless links for multiple and, in general, distributed mobile users. Previous work analyzed the rate performance of a two-user OMC system without user mobility. This paper extends the rate analysis to multiple users with mobility. The scenario of employing multiple light sources with possible user grouping is also considered. User mobility and multiple light sources lead to new challenges on the system design which are addressed for broadcast downlink communication in this work. Simulations show that user mobility decreases the rate, and the way of how to utilize multiple light sources has great impact on the performance. In particular, simultaneous power division usage of multiple light sources through user grouping and power allocation brings almost no gain as compared with the case of single light source. On the other hand, time division usage of multiple light sources is capable of compensating for the hardware deficiency and thus increasing the rate greatly. It is found that OMC is not only superior to the conventional scheme with nonadjustable channel gains but also outperforms free space optical scheme at high signal-to-noise ratio region.

scholarly journals Development of mobile communication systems for high-speed railway

2021 ◽  
Vol 1 (1) ◽  
pp. 29-34
Author(s):  
Nedžad Branković ◽  
Aida Kalem ◽  
Adisa Medić
Keyword(s):  
Mobile Communication ◽  
Mobile Communications ◽  
Traffic Management ◽  
Communication Systems ◽  
High Speed ◽  
Data Communication ◽  
Mobile Communication Systems ◽  
Transport Services ◽  
Traffic Management System ◽  
Set Up

Development of high-speed railways set up challenges for new communication technologies. With the increase in speed, new requirements for communication systems have emerged that HSR requires greater reliability, capacity and shorter response time for efficient and safe operations. Mobile communication systems are crucial for the competitiveness of the railway industry and therefore have become one of the priorities addressed by the participants in the railway system to take advantage of technological opportunities to improve operational processes and the quality of provided transport services. The European Rail Traffic Management System (ERTMS) uses the Global System for Mobile Communications for Railways (GSM-R) for voice and data communication to communicate between trains and control centers. The International Railway Union is exploring new ways of communicating for high-speed railways because as speed increases this system becomes unreliable in information transmission. This paperwork presents an analysis of the evolution of communications on European railways since the usage of GSM-R. In addition, an overview of the various alternative solutions proposed during the time (LTE-R, Future Railway Mobile Communication System) as possible successors to GSM-R technology is given.

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