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.