TD-SCDMA Relay Networks

PhDWhen this research was started, TD-SCDMA (Time Division Synchronous Code Division Multiple Access) was still in the research/ development phase, but now, at the time of writing this thesis, it is in commercial use in 10 large cities in China including Beijing and Shang Hai. In all of these cities HSDPA is enabled. The roll-out of the commercial deployment is progressing fast with installations in another 28 cities being underway now. However, during the pre-commercial TD-SCDM trail in China, which started from year 2006, some interference problems have been noticed especially in the network planning and initialization phases. Interference is always an issue in any network and the goal of the work reported in this thesis is to improve network coverage and capacity in the presence of interference. Based on an analysis of TD-SCDMA issues and how network interference arises, this thesis proposes two enhancements to the network in addition to the standard N-frequency technique. These are (i) the introduction of the concentric circle cell concept and (ii) the addition of a relay network that makes use of other users at the cell boundary. This overall approach not only optimizes the resilience to interference but increases the network coverage without adding more Node Bs. Based on the cell planning parameters from the research, TD-SCDMA HSDPA services in dense urban area and non-HSDPA services in rural areas were simulated to investigate the network performance impact after introducing the relay network into a TD-SCDMA network. The results for HSDPA applications show significant improvement in the TDSCDMA relay network both for network capacity and network interference aspects compared to standard TD-SCDMA networks. The results for non- HSDPA service show that although the network capacity has not changed after adding in the relay network (due to the code limitation in TD-SCDMA), the TD-SCDMA relay network has better interference performance and greater coverage

Smart Antennas in 4G

Smart Antenna†technology is one of the most vital developments in mobile communication.This paper deals with the principle and working of smart antennas and the elegance of their applications in various fields such a 4G -telephony system, best suitability of multi carrier modulations such as OFDMA etc., This paper mainly concentrates on use of smart antennas in mobile communications that enhances the capabilities of the mobile and cellular system such a faster bit rate, multi use interference, space division multiplexing (SDMA), increase in range, Multi path Mitigation, reduction of errors due to multi path fading and with one great advantage that is a very high security. The signal that is been transmitted by a smart antenna cannot tracked or received any other antenna thus ensuring a very high security of the data transmitted. This paper also deals the required algorithms that are need for the beam forming in the antenna patters. The application of smart antennas such as in WI-FI transmitter , Discrete Multi Tone modulation (DMT), OFDMA and TD-SCDMA is already in real world use is also incorporated in this paper. Keywords: Multipath Fading, Beam forming basics, Switched Beam Antenna, SCDMA

Application of Smart Antenna in TD - SCDMA

With the rapid development of global communications business, future personal communication wireless mobile communicationtechnology has aroused great concern. Way to eliminate the impact of co-channel interference (CCI), multiple access interference (MAI)and multipath fading becomes a major factor in improving the performance of wireless mobile communication systems. The smart antennauses the digital signal processing technology to generate the spatial directional beam so that the antenna main beam is aligned with thedirection of arrival of the user signal. The side lobe or the zero point is aligned to the direction of the interfering signal to reach the fullefficient use of the mobile subscriber signal, thus remove or suppress the interference signal purpose. Compared with other increasinglydeep and mature interference removal technology, the application of smart antenna technology in mobile communication is even more in theascendant and showing great potential. One of the key technologies of the third generation mobile communication standard TD-SCDMAsystem submitted by our country is the intelligent antenna technology. The paper introduces the history and development of the smartantenna in detail, and deeply analyzes the application of the smart antenna in TD-SCDMA. The application of smart antenna has beendeveloped

Current Situation and Development Trend of Mobile Communication Systems

This paper introduces the development background of mobile communication and the development of mobilecommunication. It introduces the application principle, network structure, main technology, the advantages anddisadvantages of the three generations of mobile communication system respectively, and introduces the currentthird generation mobile communication system, including its technical support and research direction, analysis andcomparison of the European WCDMA system, the United States CDMA2000 system and China's TD-SCDMA systemtechnical characteristics. Finally, the development trend and prospect of future mobile communication system arediscussed

Chinese cellular telecommunications in the past and the 21st century

Cellular telecommunication technology is one of the hottest topics of the last two decades. The annual rate of user growth is more than 30 percent. It began with the first generation (1G) networks and bloomed with second generation (2G) of cellular technologies. New third generation cellular (3G) technologies aim at offering high-speed, superior-quality information service to mobile subscribers. [2] The Chinese cellular market is developing with unbelievable speed. China launched its first cellular network in 1987. At the end of 2002, it was the biggest wireless market in the world, with more than 200 million subscribers. [56] Technologies used in the migration from the 2G networks to the 3G networks are referred to as 2.5 generation or 2.5G. It is no doubt that the 3G pattern selected in China will deeply affect the competition among the 3G technologies. This thesis will forecast the 3G systems to be selected for use in China. It will begin with the 1G and 2G networks and then look into the 2.5 G and the 3G cellular telecommunication technologies in more detail. Analysis the history, culture and business conditions in China will follow. Finally, this paper will make a prediction of the principal Chinese 3G technologies that will be chosen based on analyzing concrete information. An examination of other Asia markets, such as the 3G markets in Japan, and South Korea will be included. The conclusion of this thesis is that WCDMA (Wideband Code Division Multiple Access), a 3G technology that is developed and supported by European telecommunication manufacturers, will take the lion\u27s share of the Chinese 3G market, about 65% to 70%. Another technology, CDMA2000, will take more than 20% of the Chinese 3G market share. There is also a Chinese oriented 3G technology named TD-SCDMA (Time Division Synchronous Code Division Multiple Access). With the Chinese government\u27s support, it will collect the remaining 10% to 15% market share

The 3G standard setting strategy and indigenous innovation policy in China is TD-SCDMA a flagship?

In the time of “network economy”, industries and the public have stressed several “battles for dominance” between two or more rival technologies, often involving well-known firms operating in highly visible industries. In this paper, we are going to focus on the Chinese self-developed standard TD-SCDMA to perceive the implication and target of the nation’s policy and strategy. The motivation of the research starts from the interesting fact we observed: TD-SCDMA is named as the Chinese made standard, however the Chinese hold core patent technology is still about 7%, while most of the rest part is still taken by other foreign companies. The “faultage” between the small share reality and a self made standard sweet dream implies a well plotted strategy. In order to understand it, we firstly raise the question of why the Chinese government postpones the 3G decision again and again. Then we go further to probe why the standard-setting of TD-SCDMA has aroused wide attention as a strategic tool to fulfill “indigenous innovation”, and finally becomes part of national science and technology policy to increase international competitiveness? We are going to use economics theories to understand the essence of the creation of TD-SCDMA, and its relation to China’s interests.3G, standard, innovation, China

Wireless Cellular Mobile Communications

In this article is briefly reviewed the history of wireless cellular mobile communications, examined the progress in current second generation (2G) cellular standards and discussed their migration to the third generation (3G). The European 2G cellular standard GSM and its evolution phases GPRS and EDGE are described somewhat in detail. The third generation standard UMTS taking up on GSM/GPRS core network and equipped with a new advanced access network on the basis of code division multiple access (CDMA) is investigated too. A sketch of the perspective of mobile communication beyond 3G concludes this article

Dynamic Capacity Enhancement using a Smart Antenna in Mobile Telecommunications Networks

This work describes an investigation into the performance of antennas for mobile base station applications and techniques for improving the coverage and capacity within a base station cell. The work starts by tracing the development of mobile systems, both in technical and commercial terms, from the earliest analogue systems to present day broadband systems and includes anticipated future developments. This is followed by an outline of how smart antenna systems can be utilised to improve cell coverage and capacity. A novel smart antenna system incorporating an array of slant ± 450 dual- polarised stacked patch elements four columns wide excited by a novel multi-beam forming and beam shaping network has been designed, simulated and implemented. It is found that for an ideal smart antenna array, four narrow overlapping beams, one wide “broadcast channel” beam and right and left shaped beams can be provided. Results are presented for the simulation of the smart antenna system using CST EM simulation software which inherently includes mutual coupling and the effects of a truncated ground plane on the element patterns. The results show some significant changes to the desired set of coverage patterns and various mutual coupling compensation techniques have been reviewed. An improved design technique has been developed for compensating the performance degrading effects of mutual coupling and finite ground plane dimensions in microstrip antenna arrays. The improved technique utilises combination of two previously known techniques: complex excitation weights compensation by inversion of the array mutual coupling scattering matrix and the incorporation of a WAIM (wide angle impedance matching) sheet. The technique has been applied to a novel multi-beam smart antenna array to demonstrate the efficacy of the technique by electromagnetic simulation. In addition, a demonstrator array has been constructed and tested which has yielded a positive conformation of the simulation results. For the developed demonstrator array which provides seven different beams, beams “footprints” have been predicted both for free space propagation and for urban propagation to evaluate the dynamic capacity performance of the smart antenna in a 3G mobile network. The results indicate that sector capacity can be dynamically tailored to user demand profiles by selection of the appropriate beam patterns provided by the novel smart antenna system