Research On Key Techniques Of Radio Resource Allocation In Relay-enhanced Cellular Networks

With the rapid development of civil aviation, more and more people choose civil transport for travel. But the limited manual service ability provided by airport can’t meet the growing passenger traffic demand. At the same time the airport management mode is changing from "management as the center" to "the customer as the center", how to improve the airport service level has become the core dynamics of airport IT service. The location based service is a service which provides relative value-added information based the users’ location in wireless network environment.With the location based services, the airport can provide services such as departure gate guidance and service facility guidance for airline passengers,and monitoring of airport equipment, staff and passenger flow for airport managers.This paper first introduced the wireless network technology, mainly present the standard, structure and connection establishment process of IEEE 802.11, the IEEE standard mainly defines the physical layer and MAC layer, such as the format of data frame, control frame and management frame in MAC layer, these are the basic knowledge for this research work, which is essential knowledge for the research on indoor positioning based signal strength. Thenthe existing positioning technology which is based on the WLAN and itsevaluation standard is introduced. According to whether they need to use the signal strength or not, they are divided into two categories: positioning technology that has nothing to do with the signal strength and signal strength based wireless location technology. The former includes multilateral positioning technology. The later contains propagation model and location fingerprint.To provide location-based service(LBS) in airport waiting hall, a three-dimensional location estimation method based on received signal strength and signal propagation model is proposed. Least-square approach has been applied to determine parameters of signal propagation model obtained in the first step, minimum mean squares error(MMSE) method is applied to estimate the position of target node. Compared with the two-dimensional location algorithms being widely used now, the three-dimensional location method takes into account the APs deployment highly influence on positioning, which is more suitable for this particular scene. The experimental results show that the algorithm is relatively planar localization algorithm can improve the accuracy, reduce errors to two-dimensional plane positioning algorithm, can meet the location-based service need of air passenger in the hall of the airport.Finally, the concrete realization of the location system model is introduced, including the system overallarchitecture design, database design, client side design and the server side design.Lastly tested the location effect of the location system, and the test results show that the algorithm can meet the real life application needs.