On co-existence of in-band UWB-OFDM and GPS signals: Tracking performance analysis

The problem of in-band co-existence between GPS and other potential interfering signals is viewed from the following angle in this paper: Is there a coding or modulation technique which would permit simultaneous use of GPS and other RF services occupying same bandwidth? Very low interference between the UWB radar and GPS signals can be achieved by shaping radar pulses using orthogonal frequency division multiplexing (OFDM) coding, which is a multi-carrier modulation technique targeted for commercial UWB communications. The paper shows that we can, in fact, expect a very good degree of interoperability of a system used for GPS reception and UWB-OFDM radar purposes. The benefits of using UWB sensor in conjunction with GPS can be for example, to supplement positioning algorithms with radar-collected data, as well as to perform general reconnaissance of the surrounding area. The paper includes detailed analysis of the proposed multiple-use UWB-OFDM radar/GPS receiver concept, the effect of co-existing UWB-OFDM signals on GPS receiver tracking loop carrier noise level, and the impact on the quality of GPS solution in weak GPS signal environment. A brief discussion of MATLAB implementation of the modeled scenarios is presented as well.