Modeling and Improving the Energy Performance of GPS Receivers for Location Services

Integrated GPS receivers have become a basic module in today's mobile devices. While serving as the cornerstone for location based services, GPS modules have a serious battery drain problem due to high computation load. This paper aims to reveal the impact of key software parameters on GPS energy consumption, by establishing an energy model for a standard GPS receiver architecture as found in both academic and industrial designs. In particular, our measurements show that the receiver's energy consumption is in large part linear with the number of tracked satellites as well as the length of the raw GPS signal. This leads to an energy efficient design of selective tracking algorithm with large satellite Geometric Dilution of Precision (GDOP) weight, well spatial distribution, and large signal intensity. Real experimental results on three typical scenarios show that our selective tracking algorithm provides better tradeoff between positioning accuracy and energy consumption than standard GPS receivers.