### Abstract

This paper describes a new method of time of arrival (TOA) estimation for OFDM signals in indoor multipath environments for application to location tracking systems based on time difference of arrival. The problem addressed is to estimate the line of sight (LOS) time delay between the transmitter and the receiver when the intervening multipath channel is not known. In our approach, we do not attempt to determine the detailed multipath structure of the channel but, instead, use statistical knowledge of the multipath environment to aid in the estimation of the single parameter of real interest. We separate the gross time delay (LOS time delay) from the fine multipath structure of the channel. We then assume a statistical model of the multipath structure and develop the maximum likelihood estimator of the LOS time delay under the assumed model. Analytical development reduces the estimator to an efficient form in which most of the computational effort is done off line. Simulation results are presented which compare the performance of the new estimator to one which uses the well-known MODE technique for estimating the TOA and the new estimator is shown to compare favorably, especially as the number of paths increases. The simulations also show that the estimator is robust to variations in the assumed statistical model.

Original language | English (US) |
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Title of host publication | PLANS - 2004 Position Location and Navigation Symposium |

Pages | 585-591 |

Number of pages | 7 |

State | Published - 2004 |

Event | PLANS - 2004 Position Location and Navigation Symposium - Monterey, CA, United States Duration: Apr 26 2004 → Apr 29 2004 |

### Other

Other | PLANS - 2004 Position Location and Navigation Symposium |
---|---|

Country | United States |

City | Monterey, CA |

Period | 4/26/04 → 4/29/04 |

### Fingerprint

### ASJC Scopus subject areas

- Engineering(all)

### Cite this

*PLANS - 2004 Position Location and Navigation Symposium*(pp. 585-591)

**Maximum likelihood time of arrival estimation for real-time physical location tracking of 802.11a/g mobile stations in indoor environments.** / Voltz, Peter; Hernandez, David.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*PLANS - 2004 Position Location and Navigation Symposium.*pp. 585-591, PLANS - 2004 Position Location and Navigation Symposium, Monterey, CA, United States, 4/26/04.

}

TY - GEN

T1 - Maximum likelihood time of arrival estimation for real-time physical location tracking of 802.11a/g mobile stations in indoor environments

AU - Voltz, Peter

AU - Hernandez, David

PY - 2004

Y1 - 2004

N2 - This paper describes a new method of time of arrival (TOA) estimation for OFDM signals in indoor multipath environments for application to location tracking systems based on time difference of arrival. The problem addressed is to estimate the line of sight (LOS) time delay between the transmitter and the receiver when the intervening multipath channel is not known. In our approach, we do not attempt to determine the detailed multipath structure of the channel but, instead, use statistical knowledge of the multipath environment to aid in the estimation of the single parameter of real interest. We separate the gross time delay (LOS time delay) from the fine multipath structure of the channel. We then assume a statistical model of the multipath structure and develop the maximum likelihood estimator of the LOS time delay under the assumed model. Analytical development reduces the estimator to an efficient form in which most of the computational effort is done off line. Simulation results are presented which compare the performance of the new estimator to one which uses the well-known MODE technique for estimating the TOA and the new estimator is shown to compare favorably, especially as the number of paths increases. The simulations also show that the estimator is robust to variations in the assumed statistical model.

AB - This paper describes a new method of time of arrival (TOA) estimation for OFDM signals in indoor multipath environments for application to location tracking systems based on time difference of arrival. The problem addressed is to estimate the line of sight (LOS) time delay between the transmitter and the receiver when the intervening multipath channel is not known. In our approach, we do not attempt to determine the detailed multipath structure of the channel but, instead, use statistical knowledge of the multipath environment to aid in the estimation of the single parameter of real interest. We separate the gross time delay (LOS time delay) from the fine multipath structure of the channel. We then assume a statistical model of the multipath structure and develop the maximum likelihood estimator of the LOS time delay under the assumed model. Analytical development reduces the estimator to an efficient form in which most of the computational effort is done off line. Simulation results are presented which compare the performance of the new estimator to one which uses the well-known MODE technique for estimating the TOA and the new estimator is shown to compare favorably, especially as the number of paths increases. The simulations also show that the estimator is robust to variations in the assumed statistical model.

UR - http://www.scopus.com/inward/record.url?scp=2942648085&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=2942648085&partnerID=8YFLogxK

M3 - Conference contribution

SP - 585

EP - 591

BT - PLANS - 2004 Position Location and Navigation Symposium

ER -