Method and apparatus for correlating global positioning system (GPS) pseudorandom noise (PRN) codes

摘要

In accordance with the teachings described herein, system and methods are provided for a GPS acquisition correlation scheme with a reduced memory requirement. An example system may include a memory, a local PRN code generator, correlators, adder trees, an accumulator, and an output memory. The memory may be used to store an input PRN code. The local PRN code generator generates a replica PRN code and outputs a replica PRN code. The local PRN code generator may also shift the replica PRN code for each output epoch. One or more correlators receive the input PRN code and the replica PRN code and compare a bit of the input PRN code to a bit of the replica PRN code and generates a comparison. The adder trees add the comparisons and generate a comparison output. An accumulator accumulates the comparison output and outputs an accumulated output to an output memory.