Operating Characteristics for Clipping of In-Phase and Quadrature Components of Input and/or Reference of Narrowband Correlator

摘要

For a narrowband waveform, the possibility of clipping both the in-phase and quadrature components of the input and reference for a cross-correlator is investigated analytically and confirmed numerically via simulation. Specifically, detection and false alarm probabilities are evaluated when the correlator input and/or the local reference are hard-clipped; in addition, these same probabilities are determined for the completely linear system. Results for typical signals reveal degradations, due to clipping, of the order of 1 to 3 dB, depending on the precise location of the clipper (s) and the particular signal waveform. Similar results are derived and evaluated for a baseband system, where only one clipper is used for the local reference. Comparisons with the two-clipper narrowband system reveal virtually identical degradations; thus, the inclusion of the extra clipper(s) in the second (quadrature) channel of a narrowband correlator does not ameliorate the degradation, but only serves to maintain it at the same level as for the baseband system.