A study of some key technologies of 4G system

Abstract

4G will be the certain path to the future radio and mobile communication system. This paper discussed some core technologies of 4G mobile system included security strategy, hybrid network and adaptive network in 4G. This paper also compare 3G and 4G from network structure, core network mobile terminal and the core thechonolgoy,. Moreover, the paper introduced the research status in quo. It is significant to research and construct 4G to a certain extent

Study on smart grid communications system based on new generation wireless technology

“…Without increasing the bandwidth and transmit power, using MIMO, the wireless channel capacity can be significantly improved. At the same time, to ensure data reliability and reduce error rates, 4G system is not only using channel coding, interleaving and other technologies, but also hybrid automatic retransmission (HARQ) error control for the link [5,6]. All of the above advantages of 4G create good conditions for communication in smart grid.…”

Handover vertical y convergencia hacia IP como factores clave del desarrollo de las redes 4G

“…Otros problemas se deben al alto número de puntos de conexión con diferentes operadores, con di-ferentes proveedores de aplicaciones y con acceso a internet público además de una infraestructura de acceso heterogénea y múltiples proveedores de servicios lo que eleva exponencialmente la vulnerabilidad del sistema [15]. Finalmente, para exponer el alcance que tiene la cuarta generación de redes móviles, se cita algunas de las tecnologías que actualmente se involucran en 4G: receptores con radiofrecuencia definida por software (SDR de las siglas en inglés Software-defined radio), OFDM (las siglas en inglés de Orthogonal Frequency Division Multiplexing), OFDMA (que son las siglas en inglés de Orthogonal Frequency Division Multiple Access), MIMO (que son las siglas en Inglés de Multiple Input/Multiple Output), UMB (las siglas de Ultra Mobile Broadband), E-UTRA (Envolved UTRA), UMTS y TD-SCDMA [16] [6] [17].…”

Distributed Remote Testing Research Based on Self-Union Technology

“…It has the essential difference with the current 3rd-generation mobile communications technology. This new wireless technology supports very high rate data communications, which the data peak rate can attain 1Gbps in the 100MHz bandwidth [1] [2] .…”