Motorola Corporation

Russell D Thomas

Jeffery Scott Chuprun

James H Stilwell

Mark Heng

Michael F Durkin

Maya Tampi

Robert H Granau

A GPS receiver ( ) for processing GPS satellite signals and adapted for connection to a client device ( ). The receiver ( ) includes a down converter ( ), a correlator ( ), and a microcomputer A. The microcomputer A has a microprocessor A, a first memory ( A), a second memory ( B, B), and an input/output interface ( ). The input/output interface ( ) is capable of being connected to the client device ( ). The first memory ( A) contains a first set of instructions for the microprocessor A to download and store in the second memory ( B, B) at least one time critical GPS software module (A , A , . . . A ) from the client device ( ). The first memory ( A) also contains a second set of instructions for the microprocessor A to determine whether to download and store in the second memory ( B, B) a plurality of non-time critical software modules (B , B , . . . B ) from the client device ( ).

Scalable, reconfigurable GPS receiver

An apparatus for post-correlation signal processing includes a plurality of correlators for correlating a received signal with a predetermined signal to produce a plurality of correlator output signals and a selection circuit coupled to the plurality of correlators for selecting a correlator output signal from one of the plurality of correlator output signals to provide a selected correlator output signal. A memory is coupled to the selection circuit for storing post correlation totals. A counter is coupled to the memory for synchronizing the memory with the predetermined signal. An adder is coupled to the memory and to the selection circuit for combining the selected correlator output signal with the post correlation total from the memory to form a new post correlation total. The memory replaces the previous post correlation total with the new post correlation total.

Method and apparatus for post-correlation scoring circuit

A symbol state trellis maximum likelihood detection method greatly limits the number of possible interfering symbols which require examination. This method has considerable processing advantages over other optimal maximum likelihood detection methods. For practical configurations, the symbol state trellis maximum likelihood detection method provides a performance which is less than 1 dB from the optimal maximum likelihood detection method while simultaneously providing for a similar bit error rate. The symbol state trellis maximum likelihood detection method calculates the phase errors for all paths from a present state to a previous state. Next, total path distances are calculated for previously selected paths to the previous state. The phase error associated with each of the paths from two states previous to the present state are calculated. For each symbol of the present state, only one path is selected to each symbol. This path corresponds to the path with the minimum phase error. The symbol sent may then be determined by retracing the selected paths through the trellis structure for each of the M symbols.

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Chandler, AZ, United States of America

Russell D Thomas