Multipath and co-channel signal preprocessor

摘要

A multipath signal preprocessor which permits coherent bistatic radar detection with a single omnidirectional antenna is provided. The multipath signal preprocessor separates multipath signals received at an antenna into a strong path signal and a weak path signal. The received multipath signal after filtering, amplifying, and heterodyning is separated into in-phase and quadrature signal components. A constant magnitude signal estimate having approximately the frequency and phase of the strong path signal from the multipath signal is generated. An estimate of the amplitude of the strong path signal is generated from the received multipath signal amplitude. The estimate of the amplitude of the strong path signal is multiplied by the constant magnitude signal estimate having approximately the frequency and phase of the strong path signal to obtain an estimate of the strong path signal. The estimate of the strong path signal is subtracted from the in-phase and quadrature signals to obtain difference signals which are estimates of the in-phase and quadrature components of the weak path signal. The estimates of the weak and strong path signals are supplied to a cross correlation processor to determine delay and doppler estimates.