Timing adjustment control for efficient time division duplex, frequency division duplex or hybrid time division duplex/frequency division duplex communication
US6094421A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 21, 1997 |
| Grant date | Jul 25, 2000 |
| Priority date | — |
| Expiry date | Jan 21, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W88/08
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system and method for time division duplex communication over a single frequency band wherein guard time overhead is reduced by active adjustment of reverse link transmission timing as a function of round trip propagation time. A time frame is divided into a plurality of time slots, during each of which the base station transmits to a user station and the user station transmits to the base station. Communication is initiated by a round trip timing transaction. In response to a general polling message from the base station, a user station seeking to establish communication transmits a short reply message. The base station calculates the distance of the user station by measuring the propagation delay with respect to receipt of the reply message. The base station sends a timing adjustment command to the user station instructing the user station to advance or retard its timing according to the calculated distance, so as to minimize guard times between time slots. Thereafter, the base station monitors the user station transmissions and periodically commands the user station to advance or retard its timing in a like manner. The user station may transmit a control preamble at the start …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.