An Optimized Low-Power-Consumption Tracking Algorithm Based on Navigation Message Structure for Weak Signals

Abstract

In order to reduce the power consumption of handset GNSS receivers, we present a novel algorithm that tracks signals at fixed positions of the navigation message in an intermittent mode. The tracking channels only run during the beginning part of the message frame. In the rest they remain in idle state, to reduce power consumption of the channel. The beginning position of each message frame can be estimated accurately, and the beginning messages are constant or can be estimated, thus the coherent integration time can exceed one navigation bit, which can improve the Doppler frequency estimated accuracy. At the fixed position of the frame, the tracking channel only tracks the pseudo-code phase, and does not track the carrier frequency and phase. This algorithm can keep stable tracking for weak signals with 28 dBHz carrier-to-noise ratio (C/N0), while using only 2% of the power required by the computation associated with the traditional tracking.