Abstract: Built-in test equipment (BITE) incorporated in a GPS receiver for providing a loop forward test. The loop forward test capability may be combined with a loop backward capability to provide a comprehensive built-in test (BIT) capability for the signal path in a GPS receiver. A code generator generates deterministic test code signals such as C/A code, P code and pseudo M code that are used to modulate one or more radio frequency (RF) carriers to produce RF test signals. The RF test signals are injected into the GPS receiver's RF input. The RF test signal signals are then down-converted and demodulated through an operational signal path of the GPS receiver. The processed test signals may then be compared to the initial test data. A loop backward BITE may also be used to sample the positioning data output by the receiver.

Abstract: Built-in test equipment (BITE) incorporated in a GPS receiver for providing a loop forward test. The loop forward test capability may be combined with a loop backward capability to provide a comprehensive built-in test (BIT) capability for the signal path in a GPS receiver. A code generator generates deterministic test code signals such as C/A code, P code and pseudo M code that are used to modulate one or more radio frequency (RF) carriers to produce RF test signals. The RF test signals are injected into the GPS receiver's RF input. The RF test signal signals are then down-converted and demodulated through an operational signal path of the GPS receiver. The processed test signals may then be compared to the initial test data. A loop backward BITE may also be used to sample the positioning data output by the receiver.

Abstract: A Global Positioning System (GPS) receiver includes multiple correlation segments that can operate in parallel. Each correlation segment has a separate set of accumulators associated with it, embodied in random access memory (RAM). In each of the correlation segments, correlation data associated with an input code and a reference code are generated. The multiple correlation segments are cross-coupled, so that correlation data generated in each correlation segment are added to correlation data generated in each other correlation segment. The combined correlation data in each correlation segment are stored in the accumulators of each corresponding correlation segment, such that the accumulators of only one correlation segment are accessed at a time, reducing power consumption resulting from accessing RAM.