A system and method are provided for determining a position of a Global
Positioning System (GPS) receiver prior to bit and frame synchronization.
As such, the time-to-first-fix is substantially reduced. More
specifically, pseudoranges to five GPS satellites are measured by
correlating locally generated Pseudo-Random Number (PRN) codes with
signals received from the GPS satellites. After correlation, the
pseudorange measurements are correct with an unknown integer number of
milliseconds error, which is different for each of the pseudorange
measurements. Using the measurements of the pseudoranges and a
mathematical model where each of the pseudorange measurements is forced
to have a common channel time error, the user position and the common
channel time error are determined prior to bit and frame synchronization.