Design And Implementation Of Point Of Interface

With the full construction of3G communications, the existing mobile communicationnetwork combined with China Mobile GSM、 TD-SCDMA、China Unicom GSM、WCDMA and China Telecom CDMA、WCDMA2000has operate by many ways. Itmakes the communication network to be a multi-operator, multi-standard and multi-bandmode. Because of the adjustment of the structure and environment, more and more mobiledata services emerge in room. So indoor distribution system provides high-quality wirelesssignals coverage comprehensively seems extremely important.Traditional indoor coverage solutions can not avoid problems such as increasedantenna, redundant construction and interference of multi-networks, becausemulti-operator competition patterns makes operateros established alone in most hot zone.With the new band used continuely and space resource constrained of major building, anew way can effectively solve the multi-standard indoor signal coverage problems bymulti-systems combined construction. Therefore, Point of Interface (POI) came into beingand gives a new idea for sharing indoor space resources and easing the construction of anoutdoor base station.The paper first introduces the significance of indoor distribution system and thefeasibility and necessity of POI system in multi-network build engineering. It focusedanalysis design principles of POI system and the multi-system interference based on thepreviously mentioned. It analysis the selection of its components and the design principleof the monitoring system combined with the case and verify that whether the POI systemindicators meet the design requirements according to tests. In the paper, the designprovides three major operators’s standard mobile communication signals and makesconsideration of multi-system interference. This design mainly uses the proposal of theuplink and downlink signals separation in order to improve the isolation between thedifferent frequency bands and reduce its nonlinear effect, so it can improve the systemintermodulation indicators effectively. The design of POI has applicate in the subway system of Xi’an in this paper, andproposes an optimal combiner structure for the design at same time, so it can better solvethe insertion loss and intermodulation indicators for the system associated with simplifyingthe design plan. It provides an easy way to solve the Multi-system Combiner similar designin the future.