Multipath canceller for cancelling a distortion caused to a radio frequency pulse by multipath transmission
US4672638A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 1984 |
| Grant date | Jun 9, 1987 |
| Priority date | — |
| Expiry date | Oct 22, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/787
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
For use in cancelling a distortion caused by multipath transmission to an original radio frequency pulse of an original pulse shape, a multipath canceller comprises a priliminary circuit for producing a distortionless pulse of the original pulse shape and a distortion cancelling circuit responsive to the distortionless pulse and each distorted pulse having the distortion for producing a distortion cancelled pulse at a correct pulse position which the original pulse would have if received through a direct path alone. The preliminary circuit may comprise a memory for the distortionless pulse. The distortion cancelling circuit may comprise an envelope detector for envelope detecting the distorted pulse to produce a detected pulse, a composer for composing the distortionless pulse with different amplitudes and pulse positions repeatedly into a composite pulse approximating the detected pulse, and a generator for generating the distortion cancelled pulse by using the distortionless pulse and a pulse position of one of the composite pulses that has an earliest occurrence. Alternatively, the preliminary circuit may comprise DFT and IDFT circuits for processing the distorted pulse into the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.