초록 ▼

A system for time division multiplexed communication over a single frequency band in which guard time overhead is reduced by active adjustment of reverse link transmission timing as a function of round trip propagation time. In one embodiment, during a first portion of a time frame, a base station i

A system for time division multiplexed communication over a single frequency band in which guard time overhead is reduced by active adjustment of reverse link transmission timing as a function of round trip propagation time. In one embodiment, during a first portion of a time frame, a base station issues a single burst segmented into time slots comprising data directed to each user station. After a single collective guard time, the user stations respond, one by one, in allocated time slots on the same frequency as the base station, with only minimal guard times between each reception. In order to prevent interference among the user transmissions, the base station measures the round trip propagation time for each user station and commands the user stations to advance or retard their transmission timing as necessary. To establish the initial range of a new user station, a short message is sent by the new user station during the collective guard portion (or, alternatively, during an available time slot), from which the base station calculates the propagation delay and hence the distance of the user station. Messages sent from the base station to the user stations may be interleaved so as to reduce the effects of potential noise or interference.

대표청구항 ▼

[ What is claimed is:] [1.] A system for communication, comprising a base station, a plurality of user stations, and a transmission format;said transmission format comprising a plurality of time frames of equal duration, each of said time frames comprising a base transmission portion, a collective g

[ What is claimed is:] [1.] A system for communication, comprising a base station, a plurality of user stations, and a transmission format;said transmission format comprising a plurality of time frames of equal duration, each of said time frames comprising a base transmission portion, a collective guard portion, and a user transmission portion, said collective guard portion located between said base transmission portion and said user transmission portion, each base transmission portion comprised of a plurality of base time slots and each user transmission portion comprised of a plurality of user time slots;said base station comprising a base station transmitter for transmitting a base-to-user message to one of a plurality of said user stations in a base time slot, said base station further comprising a propagation delay calculator, said propagation delay calculator comprising the capability to determine a propagation delay between said base station and one of said plurality of user stations, an output of said propagation delay calculator based on said propagation delay, said output transmitted to said one of said plurality of user stations;each of said plurality of user stations comprising a user station transmitter for transmitting a user-to-base message to said base station in a user time slot, said output of said propagation delay calculator transmitted to a user station used by said user station to advance or retard a timing of a transmission of a user-to-base message from said user station.