3G technology and its application in communications

Paper Keywords: 3G technology; communications; technical standards; power; rate

Abstract: Currently, 3G is still in its infancy, but its development is very promising. As the communication network and the continuous development of technology, 3G technology environment into a high-speed telecom value-added business development, business is expanding, diversified business entities tend, increasingly innovative new business model stage. This paper introduces the 3G (third generation mobile communication systems) and 3G technology, the meaning of the basic characteristics of the 3G technology in communications applications.



The future, 3G technology is full of people a better look. 3G is currently still in its infancy, but its development is very promising. As the communication network and the continuous development of technology, 3G technology environment into a high-speed telecom value-added business development, business is expanding, diversified business entities tend, increasingly innovative new business model stage.


One, 3G is the meaning of

3G 3rd Generation of the abbreviation in English, the third generation mobile communication technology. Relative to the first generation analogue phones (1G) and second-generation GSM, TDMA and other digital mobile phone (2G), third-generation mobile phones generally speaking, refers to wireless communications and multimedia communications with the Internet and other next-generation mobile communication systems. It can handle images, music, video streaming and other media in the form of services including web browsing, conference calls, e-commerce and other information services. In order to provide this service, wireless network must be able to support different data transfer speed, which means that in the indoor, outdoor and vehicular environments, respectively, can support at least 2MBps (MB / sec), 384KBps (kilobytes / second) and the transmission speed of 144KBps.


Second, 3G technology

basic characteristics have been established from the current 3G standard analysis, the network feature is mainly reflected in the radio interface technology. Cellular mobile communication system wireless technology, including cell multiplexing, multiple access / duplex mode, the application frequency, modulation, radio channel parameters, channel coding and error correction, frame structure, the physical channel structure and multiplexing mode and other aspects. Throughout the evolution of 3G wireless technology, on the one hand it is not completely abandoned the 2G, but to fully draw on the 2G network operators experience in the technical maturity of both the 2G application technology, on the other hand, established under the IMT-2000 goals, future 3G wireless technology used in the system should have high spectral efficiency, high quality of service to meet the multi-service environment, and has good flexibility and full-coverage network. 3G wireless technology innovation mainly in the following areas:

(a) of the high frequency spectrum
goal to achieve global roaming, according to ITU IMT-2000 will be a unified plan with 2G spectrum, the available bandwidth of up to 230MHz, assigned to the terrestrial network 170MHz, satellite network 60MHz, the 3G network capacity for the development of global multi-service environment provides a broad spectrum of space, and can better meet the broadband business.


(B) the use of broadband radio frequency channel to support high-speed business
fully consider the needs of carrying multimedia services, 3G network RF carrier channel based on business requirements, such as channel bandwidth used 5/10/20M the same time, further improve the chip rate, the system capacity of anti-multipath fading greatly improved.


(C) multi-service, multi-rate transmission
in the broadband channel for flexible application time multiplexing, code reuse, separate power and control the quality of each business by selecting a different spreading factor, will have different QoS requirements of the various rates of service mapping to the broadband channel, multi-service, multi-rate transmission.


(D) of fast power control
3G mainstream channels are used in the downlink fast power control loop to improve the performance of the downlink transmission channel, in this regard to improve the system capacity of anti-multipath fading On the other hand the impact of multipath channel spread-spectrum CDMA led to the orthogonality between users is not satisfactory, increase the system's deviation from the interference, but in general the application of fast power control to improve system performance is good .

(E) use of adaptive antennas and software radio technology
3G base station with a programmable electronic phase relationship with adaptive antenna arrays, beamforming can be sent a letter to adaptively adjust the power, reduce the system Since the interference and improve receiver sensitivity, increasing the system capacity, the other software radio technology in base stations and terminal products application, to improve the system flexibility and lower costs is critical. Links to Research Papers Download http://www.hi138.com