Performance Analysis of Localization Algorithms in WCDMA Systems in NLOS and LOS Environments / Amr Abdelkhalek Abdelnabi

Supervisor: Amr ElKeyi

Thesis (M.A.)—Nile University, Egypt, 2012 .

"Includes bibliographical references"

Contents:
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Background and Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Contribution of Thesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Thesis Organization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. WCDMA System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Overview of WCDMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 WCDMA System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
2.3 Basic Concepts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.4 WCDMA Uplink Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3. WCDMA Physical Channel Modeling And Time Of Arrival Estimation . . . . .13
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
3.2 Wireless Channel Impairments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
3.2.1 Path Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.2.2 Multipath Fading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2.3 Shadowing loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.3 Time of arrival Estimation (TOA Estimation) . . . . . . . . . . . . . . . . . . . . 18
4. Localization Methods in LOS and NLOS Environment . . . . . . . . . . . . . . . . . 21
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.2 Localization Procedure For LOS Signal . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.3 Localization Procedure For NLOS Signal . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.4 Simulation Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.5 Simulation Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.5.1 NLOS Localization In Urban Area . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.5.2 LOS Localization In Urban Area . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.5.3 NLOS Localization In Rural Area . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.5.4 LOS Localization In Rural Area . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
5. Conclusion and Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Bibliography . . . . . . . . . . . . . . .

Abstract:
We are now in the era of information where the demand of using the internet in the Cellular Networks is growing with a rapid pace. These large amounts of data require efficient use of the spectrum in addition to other resources in the network such as codes. Many researchers are now working to find the efficient method to decentralize the resources allocation such as frequency and codes from the BTS (Base Station Transceiver) in 2G networks or node B in 3G networks. This resource allocation has created the need to determine the location of the user precisely to increase the efficiency in assigning the resources to the near serving point. Another application of precise location estimation of the user is the commercial use by promoting some products based on the user’s location. In emergency cases, the user location can also be of great benefit to provide help and saving people’s life.
Several works were done for assessing and proposing the best localization procedures that gives the minimum error in location estimate for cellular networks. Many algorithms have been proposed that depend on either time of arrival or angle of arrival. Moreover, TDOA (Time Difference of Arrival) was also proposed but for wireless sensor networks, but the most efficient method was the AOA (Angle of Arrival). Moreover, this method requires extra hardware to be installed at each node B that is an antenna array of large number of elements, which will add extra cost and requires more space at node B.
II
In our work, we study the performance of TDOA-based localization in WCDMA-based networks where the mobile station can be covered by 3 node Bs that are considered its active set of servers to prove that the TDOA method is an efficient method for localization in WCDMA networks.
Based on existing measurements performed for the WCDMA’s propagation channel for two different clutter types, comparative analysis of the different localization algorithms used for Line of sight (LOS) and Non Line Of Sight (NLOS) were studied. The analysis was done at a range of SNR values to count to test the efficiency of the algorithms at different noise power values. Comparison of the efficiency of localization algorithms depends on the existence or absence of the line of sight component, which is included in this study.
We have used a large number of random location points, which counts the different scenarios that the users can have regarding their farness and closeness to each of the three base stations. The analysis is based on calculating the error in location estimate at different SNRs effect for different clutter type.

Text in English, abstracts in English.