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Mathematics of Multipath Distortion. Dr. A. J. Van Dierendonck AJ Systems. Multipath Effects. Composite Signal a = Relative multipath signal amplitude d = Multipath delay in seconds C f ( t ) = Pre-correlation filtered PN Code Filtered Autocorrelation Function. Composite Discriminators.
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Mathematics of Multipath Distortion Dr. A. J. Van Dierendonck AJ Systems IMA
Multipath Effects • Composite Signal • a = Relative multipath signal amplitude • d = Multipath delay in seconds • Cf(t) = Pre-correlation filtered PN Code • Filtered Autocorrelation Function IMA
Composite Discriminators • Coherent DLL • Non-Coherent DLL (Dot Product) IMA
Computing Multipath Error • Set the E(dtk) to zero; Solve (iteratively) for tk as a function of phase fm and multipath delay d • fm = 0°and 180° yields maximum error amplitude results (error envelope) IMA
MULTIPATH ERROR ENVELOPES WITH 20 MHz BANDWIDTH • Non-Coherent Discriminator; a = 0.5 IMA
MULTIPATH ERROR ENVELOPES WITH NARROWER BANDWIDTHS • Non-Coherent Discriminator; a = 0.5 IMA