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Title:	A new user localization technique using received signal strength in multi-element femtocell device
Authors:	Ahmed Afaz Uddin (P72880)
Supervisor:	Mahammad Tariqul Islam, Professor Dr.
Keywords:	Femtocell Signal strength Coverage strategy Dissertations, Academic -- Malaysia
Issue Date:	28-Jan-2015
Description:	With vast number of electronic devices and gadgets connected to the wireless system alongside with requirements such as very high data rates, extremely low latency and ultra-high reliability/availability, it is very challenging to provide high coverage and quality of service in indoor environments. In arbitrary indoor environment, the collected received signal strength indicator (RSSI) is subjected to hostile propagation and unpredictable RSSI fluctuation that does not allow raw RSSI to be used for reliable operation. In such note, femtocell, a new add- on in the small cell technology, works as an extension of the existing outdoor macrocell coverage. However, vast deployment at the user end without proper network planning and coverage strategy makes it difficult to maintain desired services. At this extent, the deployment offemtocell is mandated by the provision of directional beam forming in the femtocell antenna, coverage optimization, and cell over-shooting mitigation, which directly reflects on issues like interference management and signalling congestion. Hence, users' location estimation at femtocell end is required to steer the beam towards theregistered user and nulling the beam towards the interferers. In this research, a user localization technique is proposed by using peak RSSI measurement in a multielement femtocell device. A directional microstrip antenna is designed and fabricated to perform the test in both simulation and practical experiment. The progress in the proposed technique is developed in two stages; RSSI measurement in multi-element femtocell device and user localization process. The localization process developed utilizing two sub-stages; user categorization and direction of arrival (DoA) estimation. Moreover, a machine intelligence system is proposed to conjecture the divergences of the adverse propagation qualities. The learning process is tested for their predictive abilities and an agreement between predicted values and real values shown in the test data. Simulation and experimental results are analysed to present the performance of the process with users in both indoor and outdoor regions. Both 2D and 3D simulation were developed to evaluate and analyse the performance by using Matlab and Wireless Insite software. The experimental test is performed using Agilent Network analyser, horn antenna and a phantom multi-element femtocell. For error free user categorization, the required number of indoor and outdoor pre- profiling samples is limited to 21 and 32, respectively. The mean error in DoA estimation is smaller than 7° and standard deviation smaller than 4° while the femtocell suffers from noise and signal attenuation. The operation of closed access femtocell can be further improved with the ability to distinguish the users and steer the beam towards the registered user.,Master
Pages:	78
Call Number:	TK5103.2 .A398 2015
Publisher:	UKM, Bangi
Appears in Collections:	Institute of Climate Change / Institut Perubahan Iklim

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