Implementation of a Localization System for Sensor Networks
Abstract
Localization is very important for self-configuring wireless sensor networks. There are two main tasks to performing localization. Assuming availability of reference points, first the relationships to the reference points are established; in this thesis this relationship is the distance to the reference point. Second, using the reference point positions and the relations to these points, an algorithmic computation is carried out to compute the position. In the existing body of research on sensor network localization, the algorithmic aspects of this final position calculation have received the most attention. However there remain significant implementation issues related to both distance measurements and algorithmic computations. In this thesis the implementation issues regarding a sensor network localization system is studied along with some examples. In the first half, the implementation of a distributed, least-squares-based localization algorithm is presented. Low power and energy dissipation are key requirements for sensor networks. An ultra-low-power and dedicated hardware implementation of the localization system is presented. The cost of fixed-point implementation is also investigated. The design is implemented in a 0.13? CMOS process. It dissipates 1.7mW of active power and 0.122nJ/op of active energy with a silicon area of 0.55mm2. The mean calculated location error due to fixed-point implementation is shown to be 6%. In the second part, a radio frequency"RF" signal based Time of Flight "ToF" measuring ranging system for wireless sensor networks is proposed, designed and prototyped. The prototype measurement error is within -0.5m to 2m while operating at 100Msps sampling rate and using a 50MHz signal in the 2.4GHz ISM band. The system accuracy is limited by the sampling rate and can be linearly improved with increasing rates. This RF method is more co
Document Details
- Document Type
- Technical Report
- Publication Date
- May 18, 2006
- Accession Number
- ADA474072
Entities
People
- Tufan C. Karalar
Organizations
- University of California, Berkeley