Enhanced time of arrival method
US5742635A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 5, 1994 |
| Grant date | Apr 21, 1998 |
| Priority date | — |
| Expiry date | May 5, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B17/318
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for improving a radio location system based on time-of-arrival. Time-of-arrival radio location systems are limited in ultimate accuracy by signal-to-noise ratio and by the time varying multipath environment in which they must operate. These systems time stamp some feature of an arriving signal, from a transmitter, in order to calculate a range or a hyperbolic line-of-position. Some feature of the received signal must be identified which can provide repeatable readings, in order for a time-of-arrival system to be reliable. The present invention teaches techniques which maintain a high signal-to-noise ratio while identifying a feature of the received signal which is least affected by multipath. The technique uses correlation peak/envelope information to estimate the leading edge of the correlation function, then enhances discrete samples at the leading edge of the correlation function to yield high signal-to-noise ratio readings. The present invention can reduce required transmitted bandwidth, increase system resolution and accuracy by twenty to one, and maintain high message traffic throughput.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.