Indoor Coverage Of Wcdma In High-rise Building

Along with the global economy development, high-end hotels, shopping malls, supermarkets are constantly built all over. At the same time, the underground transportation systems are planned to be constructed in many big cities. These places mostly use reinforced frame structure, concrete, and new building materials, which cause strong shielding and absorption effect towards radio waves. It also causes bigger transmission attenuation of the mobile wireless signals, and signal weak areas even blind areas will form in indoor environment, that mobile phone users talk for one-way will break, even appear not in service phenomenon. However, these places have concentrated mobile users, if they can’t use mobile terminals in these places, it inflicts the business loss of communication operation companies directly, and even cause the loss of mobile users.At the same time, with the increase of the number of mobile users, traffic density within the building is on the rise. In downtown, traffic stops and mobile users concentration areas depend in only on outdoor microcellular coverage cannot meet capacity requirements. Statistics show that as people daily activities more and more focused on indoor environment, indoor mobile users gradually increase, which accounts for about70%of the whole conversation. But network coverage indoor is often weak.Therefore, to solve the problem of indoor coverage is important for operators and mobile users. Users want have a good communication at any time and in any place. Only operators provide seamless indoor coverage and the perfect combination of outdoor coverage, can have a better market competition, and get more market share, increase operation income and enhance the brand image of the market.Indoor coverage is not always in order to solve the blind area wireless signal coverage. Cover age is necessary only that can absorb enough traffic, so indoor coverage becomes the best solution to increasing coverage area and capacity.This paper involves the development of mobile communication from outdoor to indoor environment. It also describes the present situation of the WCDMA network, and introduces the wireless signal transmission in process of decline phenomena. By describing the environment of buildings from low-level electromagnetic environment to the top, the indoor "island","table tennis" and blind phenomenon are analyzed. A series of pilot tones pollution causes and the influence on the network are summarized, and some solving methods of the frequency pollution are advanced. The switching ways, the reasons and realizing process in WCDMA network are pointed out.A method of strengthening the weak indoor signals is proposed by an example. In this paper, some commonly concepts describing the signal quality in WCDMA network are involved, the methods of road test and signal hierarchies are also introduced. By testing the field intensity, receiving signal strength, mobile signal strength, SNR in buildings, the signal in indoor coverage of the weak link is concluded. Through the indoor simulated test method, the indoor wireless transmission model is gotten and the model is verified, and then the edge of the field intensity is analyzed and the edge of the antenna installation position is determined. In the process of selecting cover scheme, several alternative sources of characteristic and use modes are proposed, and in the light of the various scenarios, comparing several signal sources, all kinds of signal source of use of the environment are put forward. In view of the structure of the places, the electromagnetic environment, floor height and the different requirements put forward by owners, the type of source is determined. Compared with day present distribution system, optical fiber distribution system and so on, the way of the cover places is determined. Through a series of combination scheme of the several different of project, according to the structure of the building and requirements of the owner of the domain, the final scheme is summarized, and then the antenna, components and the position of source are defined.After indoor coverage system is implemented, the detail road test is taken, the coverage effect is analysis, the still existing problems are searched, and the leakage signals are analyzed. Through the calculation of the field intensity to the edge and the structure of the apartment building, the method of avoiding leak is put forward. Analysis the influence of choose base station towards the percent of call lost, the solution is put forward. From the aspects of bad quality dropping call, the weak signal dropping call and switching dropping call, the influence of indoor coverage on base station dropping call is put forward; the reasons and problem in engineering design are summarized. If indoor and outdoor the same pilot frequency signal will switch, in principle, indoor signals should be used when entered into indoor environment. According to this problem, the method of switch control and realizing smooth excessive is summarized. By the detailed calculations, the condition of uplink noise increase caused by the individual straight station brought in is summarized.At present, the problem analysis is still not perfect in this paper. With the development of all kinds of complicated engineering continuously, the more difficult problems will be exposed gradually, which will give us bigger challenges. I’ll keep working hard, finding and solving problems, which is the working orientation for our engineering personnel in the future.