Chen S.,Datang Telecom Technology |
Sun S.,Datang Telecom Technology |
Gao Q.,China Academy of Telecommunications Technology |
Su X.,China Academy of Telecommunications Technology
IEEE Wireless Communications | Year: 2016
Adaptive beamforming has been attracting considerable attention from both academia and industry for decades. It has already played an important role in modern wireless communication systems. This article provides an overview of adaptive beamforming and its application in cellular systems including the fundamental principle and schemes. This article points out that TD-SCDMA 3G spins off the commercial scale of adaptive beamforming in cellular networks. Beamforming-based spatial multiplexing is a breakthrough in adaptive beamforming and the symbolic technology of TD-LTE 4G. The standardization of adaptive beamforming in 3GPP LTE networks is summarized. To evaluate adaptive beamforming techniques, system simulation and field test results from commercial TD-LTE 4G networks are presented and associated with gains achieved through adaptive beamforming in different scenarios. Finally, future research areas of massive beamforming in 5G are envisioned. © 2002-2012 IEEE.
Wang X.,Beihang University |
Zhang X.,Beihang University |
Yang Y.,Datang Telecom Technology
Proceedings - IEEE Military Communications Conference MILCOM | Year: 2016
A two-path model, where each path includes a linear Doppler frequency offset, is commonly applied for modeling aeronautical channels under an en-route scenario. In this study, a maximum-likelihood (ML) channel estimation-based channel response differential correlation method is used to estimate a bilinear Doppler frequency offset. Specifically, reference symbols and ML estimation are used to obtain the channel response and to separate the two paths. Then, for each path, the ML frequency offset estimation is performed via a differential correlation operation. In the absence of interference, ordinary least square (LS) channel estimation and ML channel estimation demonstrate similar performance in frequency offset estimation, but the accuracy of LS channel estimation decreases dramatically in the presence of narrow-band interference, whereas ML channel estimation continues to demonstrate good accuracy, even under strong narrow-band interference, indicating high robustness. We also present a frequency offset compensation method for a two-path channel based on obtaining a maximum signal to interference ratio. The performance of the proposed methods for frequency offset estimation and compensation are validated via simulation. © 2016 IEEE.
Chen S.,Datang Telecom Technology |
Ren B.,Beijing University of Posts and Telecommunications |
Gao Q.,China Mobile |
Kang S.,China Mobile |
And 2 more authors.
IEEE Transactions on Vehicular Technology | Year: 2017
In this paper, pattern division multiple access (PDMA), which is a novel nonorthogonal multiple access scheme, is proposed for fifth-generation (5G) radio networks. The PDMA pattern defines the mapping of transmitted data to a resource group that can consist of time, frequency, and spatial resources or any combination of these resources. The pattern is introduced to differentiate signals of users sharing the same resources, and the pattern is designed with disparate diversity order and sparsity so that PDMA can take the advantage of the joint design of transmitter and receiver to improve system performance while maintaining detection complexity to a reasonable level. System level simulation results show that PDMA can support six times simultaneous connections than that of conventional and at least 30% improvement in spectrum efficiency over orthogonal frequency division multiple access. © 1967-2012 IEEE.
News Article | December 6, 2016
The global powered smart cards market, valued at US$ 2.84 Bn in 2015, will reach US$ 6.92 Bn by the end of 2024. The market is expected to experience exploding growth throughout the forecast period 2016-2024, at a healthy CAGR of 52%. Asia Pacific will remain the market leader, whereas Latin America will register the highest CAGR. By consumption, the global powered smart cards market reched 2,049.1 Mn units in 2015 and will attain 5,640.6 Mn units by 2024, at a volume CAGR of 59.2% to reach. Consumer inclination toward secured transaction is currently driving the market for powered smart cards globally. Growing popularity of smart cards as cost-competitive devices for storage, maintenance, and management of credentials will continue to provide a strong impetus to their demand in the global market. Increasing need for efficient, secure, and reliable payment transactions are anticipated to further escalate the demand. In addition, a growing number of mobile connection subscribers is also expected to fuel the market for smart cards. Leading smart card issuing companies are foreseen to capitalize on extensive growth opportunities by combining powered smart cards and an additional set of services as a service offering. Higher initial migration costs may hamper the market growth to some extent. Small scale shopkeepers and retailers are still reluctant to adopt contactless PoS systems, which is another key challenge. Moreover, consumers are also reluctant to switch to powered smart cards, as lost or stolen cards can be adversely exploited. This will continue to limit mass penetration over the forecast period. Based on type, contactless cards segment will attract hefty revenues to the global market. This segment recorded a value of US$ 1.53 Bn in 2015 and will register a market value of US$ 4.06 Bn by the end of 2024. By volume, contactless cards will reach 3,895.5 Mn units by 2024 end, up from 1,317.9 Mn units recorded in 2015. Compared to other segments, including hybrid cards and dual interface cards, contactless cards are estimated to expand at a CAGR of 11.2% over 2016-2024. Hybrid cards segment that was valued at US$ 472.8 Mn in 2015, will reach a value of US$ 971.6 Mn, expanding at a CAGR of 8.2%. Hybrid cards segment will also be a key segment that registered a value of US$ 472.8 Mn in 2015. This segment is expected to expand at a CAGR of 8.2% and attain a value of US$ 971.6 Mn by the end of the forecast period. By application, the government sector segment is predicted to register the highest consumption of powered smart cards. By value, the market value was US$ 412.4 Mn in 2015, which is foreseen to be US$ US$ 948.4 Mn, recording a CAGR of 9.7%. In terms of volume, this segment consumed 297.4 Mn units in 2015, and will consume 773.0 Mn units by the end of the forecast period. The volume CAGR will be around 11.2%. Healthcare sector segment, which recorded a value of US$ 49.1 Mn in 2015, will expand at a CAGR of 9.8% and reach a value of US$ 114.8 by 2024 end. With almost 45% of the market value share in 2016, Asia Pacific will continue to dominate the global powered smart cards market at a CAGR of 10.5%. Latin America will however emerge as the most lucrative market for smart card providers. This region is expected to witness the highest CAGR of 12.8% over the forecast period, reaching a value of US$ 660.1 Mn by 2024 end, from US$ 217.5 Mn in 2015. Some of the key players competing in the global smart cards market include Safran Identity and Security (Morpho SA), Oberthur Technologies, Gemalto NV, Giesecke & Devrient GmbH, Eastcompeace Technology Co. Ltd., Watchdata Technologies Ltd., Datang Telecom Technology Co. Ltd., Wuhan Tianyu Information Industry Co. Ltd., Infineon Technologies AG, NXP Semiconductors N.V., Shanghai Huahong Integrated Circuit Co. Ltd., Samsung, and Texas Instruments Incorporated. For More Information Request TOC (desk of content material), Figures and Tables of the report @ http://www.persistencemarketresearch.com/market-research/powered-smart-card-market/toc Long-term Outlook: The global powered smart cards market is expected to attain the revenues of US$ 6.9 Bn by the end of the forecast period, 2016-2024. The market will witness a hefty CAGR of 52%.
News Article | November 23, 2016
In terms of consumption, the global powered smart card market stood at 2,049.1 Mn units in 2015 and is expected to register a volume CAGR of 59.2% to reach 5,640.6 Mn units by 2024 end. In a new report titled “Powered Smart Card Market: Global Industry Analysis & Forecast, 2016–2024”, Persistence Market Research studies the performance of the global powered smart card market over an eight-year forecast period (2016 – 2024) and analyzes the key factors and trends impacting market growth. Need of secure and reliable payment methods and increasing mobile phone users globally are factors anticipated to drive growth of the global powered smart card market over the forecast period. Improving security in offices and residential buildings and preventing crimes across international borders are other factors likely to push the global powered smart card market demand during the forecast period. However, factors such as high cost of migration to contactless payment systems and technical issues faced by enterprises are major challenges expected to be faced by market players operating in the global powered smart card market during the forecast period. Major opportunities for growth in the global powered smart card market lie in the convergence of powered smart cards and additional services that card issuing companies could include as part of their offering. The global powered smart card market is segmented on the basis of Type (Contactless Cards, Dual-interface Cards, Hybrid Cards); on the basis of Application (Government Sector, Healthcare Sector, Transportation Sector, Telecommunication Sector, Pay TV Sector, Financial Services, Retail, and Loyalty Sector, and Energy and Utility Sector (Smart Meters for Electricity, Water and Gas)); and on the basis of Region (North America, Latin America, Europe, Asia Pacific, Middle East & Africa). In terms of consumption, the Contactless Card segment in the global powered smart card market stood at 1,317.9 Mn units in 2015 and is expected to register a CAGR of 12.6% to reach 3,895.5 Mn units by 2024 end. This segment is expected to witness comparatively higher Y-o-Y growth throughout the forecast period. The Hybrid Cards segment in the global powered smart card market was valued at US$ 472.8 Mn in 2015 and is expected to expand at a CAGR of 8.2% to reach US$ 971.6 Mn by 2024. The Government Sector segment in the global powered smart card market was valued at US$ 412.4 Mn in 2015 and is expected to reach US$ 948.4 Mn by 2024, witnessing a CAGR of 9.7%. Among regions, the Latin America market is expected to witness comparatively higher Y-o-Y growth throughout the forecast period. The Latin America powered smart card market was valued at US$ 217.5 Mn in 2015 and is projected to reach US$ 660.1 Mn by 2024. Asia Pacific is likely to remain the dominant market in terms of revenue in the global powered smart card market and is expected to witness a CAGR of 10.5%. Safran Identity and Security (Morpho SA), Oberthur Technologies, Gemalto NV, Giesecke & Devrient GmbH, Eastcompeace Technology Co. Ltd., Watchdata Technologies Ltd., Datang Telecom Technology Co. Ltd., Wuhan Tianyu Information Industry Co. Ltd., Infineon Technologies AG, NXP Semiconductors N.V., Shanghai Huahong Integrated Circuit Co. Ltd., Samsung, and Texas Instruments Incorporated are some of the companies operating in the global powered smart card market. Market players are focusing on innovative ways to expand their customer base and consolidate their position in the market. With extensive presence worldwide and extensive product offerings catering to the demand for payment in government and telecom applications, key players are focused on gaining significant revenue share in the global powered smart card market.
Chen S.,Datang Telecom Technology |
Shi Y.,Beijing University of Posts and Telecommunications |
Hu B.,Beijing University of Posts and Telecommunications |
Ai M.,Datang Telecom Technology
IEEE Network | Year: 2014
Mobility is nature in the world and has evolved into an inherent feature and a key driving force of the future network, although only treated as one aspect in a specific network when it originated in a cellular system. Confronting emerging communication paradigms such as mobile social networks, mobile cloud computing, Internet-of-Things, and the expectation of ubiquitous and seamless connectivity, the existing mobility management technologies face problems such as function redundancy, system complexity, and inefficiency. In this article we propose Mobility-Driven Network (MDN) as the vision of mobility management under a systematic and unified methodology. The design philosophy of vertical decoupling the mobility entity into service-entity and device-entity, and horizontal decoupling the entity-identity and locator-identifier, are both discussed. The design philosophy is applied in the proposed function reference model and protocol reference model of MDN to abstract the mobility support functions, entities, and principles. Finally, the open issues in MDN are discussed. © 1986-2012 IEEE.
Zhu X.,Datang Telecom Technology |
Chen S.,Datang Telecom Technology |
Hu H.,Datang Telecom Technology |
Su X.,China Mobile |
Shi Y.,Beijing University of Posts and Telecommunications
IEEE Wireless Communications | Year: 2013
Mobile communication solutions for highspeed railway scenarios aim at providing seamless coverage, high system capacity and a high data rate for end users, which in turn face the challenges of Doppler frequency shift, penetration loss, mobility management and system capacity planning. Because the scarcity of frequency resources and increasing wireless broadband requirements have become very serious problems worldwide, increasing attention has been focused on time-division duplexing based technology, on which we focus in this article. Time-division synchronous code-division multiple access based and time-division Long Term Evolution based solutions are introduced with appropriate technology analysis. The experimental results of TD-SCDMA-based solutions in the Shanghai maglev high-speed network environment and the simulation results of TD-LTEbased solutions are presented. Finally, to improve performance, we discuss an enhanced solution based on mobile relays with performance evaluation, which is considered as a more comprehensive solution for high-speed railway scenarios. © 2002-2012 IEEE.
Peng L.,Beihang University |
Liu D.,Datang Telecom Technology
Proceedings - 2013 7th International Conference on Image and Graphics, ICIG 2013 | Year: 2013
The depth of field (DoF) in photography is limited by the aperture size and focal length. When the focal length is definite, large aperture size leads to small DoF. In dark scene, we use a large aperture at the cost of deep DoF. The paper gives a detailed analysis of the focused plenoptic camera mode presented by Georgiev and Lumsdaine, and proposes a novel reconstruction algorithm. It recovers the image from radiance samples captured on the sensor and can get images of extended DoF to all-in-focus even with large aperture size. Beside, it can change the angle of view after the exposure. Depth of field of the rendered photo in this algorithm is also studied. The simulation result shows that under the assist of new algorithm, the DoF can be extended greatly. © 2013 IEEE.
Cheng Z.,Datang Telecom Technology |
Chen S.,Datang Telecom Technology
Wireless Personal Communications | Year: 2015
Most of the existing routing protocols from those in the terrestrial networks can not be directly applied in Deep Space Information Networks (DSINs), because of its inherent outstanding characteristics, such as bandwidth constraints, high latency, asymmetric data rates, and heterogeneous network architectures. Therefore, designing an optimal routing algorithm that is suitable for DSINs becomes a challenging and interesting problem. In this paper, a bandwidth allocation scheme based on non-cooperative differential game is proposed. Our scheme takes the selfness of nodes into consideration. It is shown that our proposed scheme can effectively allocate bandwidth with bandwidth constraints, and is more feasible and adaptive to DSINs with bandwidth constraints. © 2015 Springer Science+Business Media New York