Satellite navigation receiver having a configurable acquisition engine

Abstract

A satellite navigation receiver having a flexible acquisition and tracking engine architecture. The flexible acquisition engine has a reconfigurable delay line that can be used either as a single entity or divided into different sections. Consequently, it can be configured to search different satellite vehicles, a single Doppler frequency, and full CA code in parallel. When configuring the delay line into different sections, each section is used to search a partial CA code. In this configuration, multiple Doppler mode, multiple satellite vehicles, multiple Doppler frequencies, and partial CA code can be searched in parallel. Furthermore, the different sections of the CA code can be time-multiplexed into a correlator, which can then be over clocked to achieve full CA code correlation. The flexible tracking engine includes a number of parallel tracking channels, whereby each individual channel has a number of taps or fingers, which can be used to lock onto different delays. During tracking, one of the taps can be used to lock on to the center of the peak. This leaves the other taps free to be used to perform other functions, such as determining the shape of the peak, detecting earlier arrivals for line of sight component, and obtaining an estimate of the noise floor. The flexible tracking engine is configurable to help acquisition functions, such as fine acquisition, false trigger detection, and/or fast reacquisition.