Comparison of 'Direct RF Sampling' and 'Down-Convert and Sampling' Global Positioning System (GPS) Front End Receiver Architectures

摘要

This report presents the final results of an investigation into direct radio frequency (RF) sampling receiver front ends and compares their performance to the traditional digital receiver front end designs. The distinction between the two implementations is that a direct RF sampling front end uses no analog frequency down conversion, rather the information bandwidth is aliased through the sampling process. This type of design significantly simplifies multiple frequency receiver design, important for receivers used in the Global Positioning System. However, the consequences of such an architecture are not fully understood as the technology required for their implementation has only recent become available. Past work has shown the feasible of the approach. This effort and report document the impact on the resulting phase noise, an important element in receiver design, as a result of the direct RF sampling.