Direction finding and mapping in multipath environments
First Claim
1. A method for determining a direction of a direct arrival path between a receiver and a transmitter in a multipath environment wherein a received signal at the receiver includes a direct path signal component of a transmitted signal and a plurality of multipath signal components of the transmitted signal and wherein there is relative motion between at least two of the transmitter, the receiver and the scatterers of the multipath environment, comprising the steps of:
- identifying in the received signal a doppler pedestal comprised of a plurality of multipath signal components having a range of doppler shifts, each multipath doppler shift being determined by a relative motion between a scatterer and at least one of the transmitter and the receiver, and a direct path signal component having a amplitude greater than an average amplitude of the doppler pedestal, and determining a direction and a magnitude of a doppler shift of the direct path signal component relative to the doppler pedestal as proportional to a relative speed and heading between the transmitter and the receiver.
1 Assignment
0 Petitions
Accused Products
Abstract
Determining the direction of a direct arrival path between a receiver and a transmitter in a multipath environment by determining a transmitter heading relative to the receiver as proportional to a frequency offset of the direct path signal component relative to a multipath pedestal, an absolute velocity of the transmitter as proportional to a width of the multipath pedestal, a relative velocity between the transmitter and the receiver as proportional to a magnitude and a direction of doppler shift of the direct arrival component of the received signal relative to the doppler pedestal, and an amplitude of the multipath pedestal as proportional to a number and magnitude of scatterers in the multipath environment. The method is applied for continuous wave and modulated signals, for stationary and moving transmitters and for tracking and mapping transmitter paths.
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Citations
10 Claims
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1. A method for determining a direction of a direct arrival path between a receiver and a transmitter in a multipath environment wherein a received signal at the receiver includes a direct path signal component of a transmitted signal and a plurality of multipath signal components of the transmitted signal and wherein there is relative motion between at least two of the transmitter, the receiver and the scatterers of the multipath environment, comprising the steps of:
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identifying in the received signal a doppler pedestal comprised of a plurality of multipath signal components having a range of doppler shifts, each multipath doppler shift being determined by a relative motion between a scatterer and at least one of the transmitter and the receiver, and a direct path signal component having a amplitude greater than an average amplitude of the doppler pedestal, and determining a direction and a magnitude of a doppler shift of the direct path signal component relative to the doppler pedestal as proportional to a relative speed and heading between the transmitter and the receiver. - View Dependent Claims (2)
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3. A method for determining a direction of a direct arrival path between a receiver and a transmitter in a multipath environment wherein a received signal at the receiver includes a direct path signal component of a transmitted signal and a plurality of multipath signal components of the transmitted signal and wherein the transmitter is in motion, comprising the steps of:
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identifying in the received signal a doppler pedestal comprised of a plurality of multipath signal components having a range of doppler shifts, each multipath doppler shift being determined by a relative motion between a scatterer and at least one of the transmitter and the receiver, and a direct path signal component, and determining at least one of a transmitter heading relative to the receiver as proportional to a frequency offset of the direct path signal component relative to the multipath pedestal, and an absolute velocity of the transmitter as proportional to a width of the multipath pedestal. - View Dependent Claims (4, 5, 6, 7, 8, 9)
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10. A method for determining a location of a receiver in a multi-path environment, comprising:
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detecting first and second received signals from corresponding first and second transmitters, wherein there is relative motion between the receiver and the first and second transmitters and the first and second received signals each include a direct path signal component and multipath pedestal including a plurality of multipath signal components from a corresponding one of the first and second transmitters, determining first and second directions of first and second direct arrival paths between the receiver and corresponding ones of the first and second transmitters wherein the direction of each direct arrival path is proportional to a corresponding frequency offset of the corresponding direct path signal component relative to the corresponding multipath pedestal of the corresponding received signal, and determining the location of the receiver as at an intersection of the first and second directions of the first and second direct arrival paths.
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Specification