US6388997B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Timing adjustment control for efficient time division duplex communication
Assignee: Intel Corp
•
Filing: 2000-04-25
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Granted: 2002-05-14
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Expires: 2020-04-25
Abstract
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 of each time slot to allow the base station to perform round trip timing calculations, and/or to allow adjustment or user station power or antenna selection.
Inventors
- 👤 Logan Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:09
CPC Classifications
H; H04; H04J; H04J13/00; H04B; H04B7/00; H04B7/24; H04B7/26; H04B7/2643; H04B7/2656; H04J3/00; H04J3/02; H04J3/06; H04J3/0635; H04J3/0682; H04W; H04W56/00; H04W56/0005; H04W56/004; H04W56/0045; H04W56/0055; H04W56/0065; H04W56/009; H04W24/00; H04W28/00; H04W28/02; H04W28/06; H04W48/00; H04W48/08; H04W74/00; H04W74/04; H04W74/06; H04W76/00; H04W76/10; H04W88/00; H04W88/08
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
255 words
A system for communicating with a plurality of user stations, comprising: a base station; 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 polling message from the base station to two or more of the plurality of said user stations in a base time slot of a first of said time frames, said base station comprising a base station receiver for receiving a reply message from at least one of said two or more user stations during the collective guard band portion of said first time frame; a propagation delay calculator, said propagation delay calculator comprising the capability to determine a propagation delay between said base station and said at least one user station; and said base station transmitter further for transmitting a timing command during the base transmission portion of a time frame subsequent to the first time frame to the at least one user station for instructing the at least one user station to adjust the transmission time of the at least one user station, the timing command based at least in part on said propagation delay.
Claim 2
Independent Claim
255 words
A system for communicating with a plurality of user stations, comprising: a base station; 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 polling message from the base station to two or more of the plurality of said user stations in a base time slot of a first of said time frames, said base station comprising a base station receiver for receiving a reply message from at least one of said two or more user stations during the collective guard band portion of said first time frame; a propagation delay calculator, said propagation delay calculator comprising the capability to determine a propagation delay between said base station and said at least one user station; and said base station transmitter further for transmitting a timing command during the base transmission portion of a time frame subsequent to the first time frame to the at least one user station for instructing the at least one user station to adjust the transmission time of the at least one user station, the timing command based at least in part on said propagation delay.
Claim 3
Dependent Claim
70 words
The system of claim 1 , wherein said at least one user station comprises a user station transmitter for transmitting a user-to-base message to said base station during one of said user time slots, said timing command transmitted to the at least one user station used by said at least one user station to advance or retard a timing of a transmission of the user-to-base message from said user station.
Claim 4
Dependent Claim
28 words
The system of claim 1 wherein said base station comprises circuitry for transmitting to one or more of the plurality of user stations using a spread spectrum technique.
Claim 5
Dependent Claim
60 words
The system of claim 1 wherein said user transmission portion of a time frame further comprises abbreviated guard bands separating said time slots of said user transmission portion, each said abbreviated guard band having a duration of less than a full round trip propagation delay time relative to a radius of a cell in which said base station is located.
Claim 6
Independent Claim
257 words
A system for communicating with a plurality of user stations, comprising: a base station; 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 polling message from the base station to two or more of the plurality of said user stations in a base time slot of a first of said time frames, said base station comprising a base station receiver for receiving a reply message from the at least one of said two or more user stations during one of said user time slots of said first time frame; a propagation delay calculator, said propagation delay calculator comprising the capability to determine a propagation delay between said base station and said at least one user station; and said base station transmitter further for transmitting a timing command during the base transmission portion of a time frame subsequent to said first time frame to the at least one user station for instructing the at least one user station to adjust the transmission time of the at least one user station, the timing command based at least in part on said propagation delay.
Claim 7
Independent Claim
257 words
A system for communicating with a plurality of user stations, comprising: a base station; 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 polling message from the base station to two or more of the plurality of said user stations in a base time slot of a first of said time frames, said base station comprising a base station receiver for receiving a reply message from the at least one of said two or more user stations during one of said user time slots of said first time frame; a propagation delay calculator, said propagation delay calculator comprising the capability to determine a propagation delay between said base station and said at least one user station; and said base station transmitter further for transmitting a timing command during the base transmission portion of a time frame subsequent to said first time frame to the at least one user station for instructing the at least one user station to adjust the transmission time of the at least one user station, the timing command based at least in part on said propagation delay.
Claim 8
Dependent Claim
70 words
The system of claim 5 , wherein said at least one user station comprises a user station transmitter for transmitting a user-to-base message to said base station during one of said user time slots, said timing command transmitted to the at least one user station used by said at least one user station to advance or retard a timing of a transmission of the user-to-base message from said user station.
Claim 9
Dependent Claim
28 words
The system of claim 5 wherein said base station comprises circuitry for transmitting to one or more of the plurality of user stations using a spread spectrum technique.
Claim 10
Dependent Claim
60 words
The system of claim 5 wherein said user transmission portion of a time frame further comprises abbreviated guard bands separating said time slots of said user transmission portion, each said abbreviated guard band having a duration of less than a full round trip propagation delay time relative to a radius of a cell in which said base station is located.
Claim 11
Dependent Claim
32 words
The system of claim 5 wherein said one of user time slots that said user station transmits said reply message during is the first user time slot of said first time frame.
Claim 12
Dependent Claim
37 words
The system of claim 6 wherein said one of user time slots that said user station transmits said user-to-base message during is the first user time slot of a time frame subsequent to said first time frame.
Claim 13
Dependent Claim
218 words
In a base station, a method for communicating with a plurality of user stations, comprising: using a 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; transmitting a polling message from the base station to two or more of the plurality of said user stations in a base time slot of a first of said time frames, receiving a reply message from at least one of said two or more user stations during the collective guard band portion of said first time frame; determining a propagation delay between said base station and said at least one user station; and transmitting a timing command during the base transmission portion of a time frame subsequent to said first time frame to the at least one user station for instructing the at least one user station to adjust the transmission time of the at least one user station, the timing command based at least in part on said propagation delay.
Claim 14
Dependent Claim
218 words
In a base station, a method for communicating with a plurality of user stations, comprising: using a 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; transmitting a polling message from the base station to two or more of the plurality of said user stations in a base time slot of a first of said time frames, receiving a reply message from at least one of said two or more user stations during the collective guard band portion of said first time frame; determining a propagation delay between said base station and said at least one user station; and transmitting a timing command during the base transmission portion of a time frame subsequent to said first time frame to the at least one user station for instructing the at least one user station to adjust the transmission time of the at least one user station, the timing command based at least in part on said propagation delay.
Claim 15
Dependent Claim
43 words
The method of claim 11 , comprising advancing or retarding the transmission time of a user-to-base message from said user station to base station during one of said user time slots using the propagation delay transmitted to the at least one user station.
Claim 16
Dependent Claim
22 words
The method of claim 11 comprising transmitting to one or more of the plurality of user stations using a spread spectrum technique.
Claim 17
Dependent Claim
60 words
The method of claim 11 wherein said user transmission portion of a time frame further comprises abbreviated guard bands separating said time slots of said user transmission portion, each said abbreviated guard band having a duration of less than a full round trip propagation delay time relative to a radius of a cell in which said base station is located.
Claim 18
Dependent Claim
215 words
In a base station, a method for communicating with a plurality of user stations, comprising: using a 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; transmitting a polling message from the base station to two or more of the plurality of said user stations in a base time slot of a first of said time frames, receiving a reply message from the at least one user station during one of said user time slots of said first time frame; determining a propagation delay between said base station and said at least one user station; and transmitting a timing command during the base transmission portion of a time frame subsequent to said first time frame to the at least one user station for instructing the at least one user station to adjust the transmission time of the at least one user station, the timing command based at least in part on said propagation delay.
Claim 19
Dependent Claim
215 words
In a base station, a method for communicating with a plurality of user stations, comprising: using a 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; transmitting a polling message from the base station to two or more of the plurality of said user stations in a base time slot of a first of said time frames, receiving a reply message from the at least one user station during one of said user time slots of said first time frame; determining a propagation delay between said base station and said at least one user station; and transmitting a timing command during the base transmission portion of a time frame subsequent to said first time frame to the at least one user station for instructing the at least one user station to adjust the transmission time of the at least one user station, the timing command based at least in part on said propagation delay.
Claim 20
Dependent Claim
43 words
The method of claim 15 , comprising advancing or retarding the transmission time of a user-to-base message from said user station to base station during one of said user time slots using the propagation delay transmitted to the at least one user station.
Claim 21
Dependent Claim
22 words
The method of claim 15 comprising transmitting to one or more of the plurality of user stations using a spread spectrum technique.
Claim 22
Dependent Claim
60 words
The method of claim 15 wherein said user transmission portion of a time frame further comprises abbreviated guard bands separating said time slots of said user transmission portion, each said abbreviated guard band having a duration of less than a full round trip propagation delay time relative to a radius of a cell in which said base station is located.
Claim 23
Dependent Claim
32 words
The method of claim 15 wherein said one of user time slots that said user station transmits said reply message during is the first user time slot of said first time frame.
Claim 24
Dependent Claim
37 words
The method of claim 16 wherein said one of user time slots that said user station transmits said user-to-base message during is the first user time slot of a time frame subsequent to said first time frame.
Claim 25
Dependent Claim
223 words
In a base station, a method for communicating with a plurality of user stations, comprising: using a 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; transmitting a polling message from the base station to two or more of the plurality of said user stations in a base time slot of a first of said time frames, receiving a reply message from each of said two or more user stations during the collective guard band portion of said first time frame; selecting one of said two or more user stations based on a predetermined selection criteria; determining a propagation delay between said base station and the selected user station; and transmitting a timing command during the base transmission portion of a time frame subsequent to said first time frame to the selected user station for instructing the selected user station to adjust the transmission time of the selected user station, the timing command based at least in part on said propagation delay.
Claim 26
Dependent Claim
223 words
In a base station, a method for communicating with a plurality of user stations, comprising: using a 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; transmitting a polling message from the base station to two or more of the plurality of said user stations in a base time slot of a first of said time frames, receiving a reply message from each of said two or more user stations during the collective guard band portion of said first time frame; selecting one of said two or more user stations based on a predetermined selection criteria; determining a propagation delay between said base station and the selected user station; and transmitting a timing command during the base transmission portion of a time frame subsequent to said first time frame to the selected user station for instructing the selected user station to adjust the transmission time of the selected user station, the timing command based at least in part on said propagation delay.
Claim 27
Dependent Claim
36 words
The method of claim 21 wherein said step of selecting based on said predetermined selection criteria comprises selecting the one user station of the two or more user stations from which the strongest signal is received.
Claim 28
Dependent Claim
40 words
The method of claim 21 wherein said step of selecting based on said predetermined selection criteria comprises selecting the one user station of the two or more user stations based on an internal programming parameter unique to each user station.
Claim 29
Dependent Claim
16 words
The method of claim 23 wherein said internal programming parameter comprises a unique user identification number.
Claim 30
Dependent Claim
224 words
In a base station, a method for communicating with a plurality of user stations, comprising: using a 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; transmitting a polling message from the base station to two or more of the plurality of said user stations in a base time slot of a first of said time frames, receiving a reply message from each of said two or more user stations during one of said user time slots of said first time frame; selecting one of said two or more user stations based on a predetermined selection criteria; determining a propagation delay between said base station and the selected user station; and transmitting a timing command during the base transmission portion of a time frame subsequent to said first time frame to the selected user station for instructing the selected user station to adjust the transmission time of the selected user station, the timing command based at least in part on said propagation delay.
Claim 31
Dependent Claim
224 words
In a base station, a method for communicating with a plurality of user stations, comprising: using a 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; transmitting a polling message from the base station to two or more of the plurality of said user stations in a base time slot of a first of said time frames, receiving a reply message from each of said two or more user stations during one of said user time slots of said first time frame; selecting one of said two or more user stations based on a predetermined selection criteria; determining a propagation delay between said base station and the selected user station; and transmitting a timing command during the base transmission portion of a time frame subsequent to said first time frame to the selected user station for instructing the selected user station to adjust the transmission time of the selected user station, the timing command based at least in part on said propagation delay.
Claim 32
Dependent Claim
36 words
The method of claim 25 wherein said step of selecting based on said predetermined selection criteria comprises selecting the one user station of the two or more user stations from which the strongest signal is received.
Claim 33
Dependent Claim
40 words
The method of claim 25 wherein said step of selecting based on said predetermined selection criteria comprises selecting the one user station of the two or more user stations based on an internal programming parameter unique to each user station.
Claim 34
Dependent Claim
16 words
The method of claim 27 wherein said internal programming parameter comprises a unique user identification number.
References Cited (Backward Citations)
US4638494A
Cited
US3838221A
Cited
US3795864A
Cited
US4217563A
Cited
US4189677A
Cited
US4222115A
Cited
US4301530A
Cited
US4291410A
Cited
US4355411A
Cited
US4324001A
Cited
US4418393A
Cited
US4525835A
Cited
US4506372A
Cited
US4432089A
Cited
US4513416A
Cited
US4481640A
Cited
US4484028A
Cited
US4494211A
Cited
US4587662A
Cited
US4612637A
Cited
AU3984485A
Cited
US4621365A
Cited
US5022024A
Cited
US4675863A
Cited
US5022024B1
Cited
US5121391A
Cited
US5119375A
Cited
US4817089B1
Cited
US4912705A
Cited
US4817089A
Cited
US4688210A
Cited
US4742512A
Cited
US4754453A
Cited
US4672658A
Cited
US4701904A
Cited
US4724435A
Cited
US4736371A
Cited
US4696051A
Cited
US4703474A
Cited
US4765753A
Cited
US4807222A
Cited
US4901307A
Cited
US4797947A
Cited
US4905221A
Cited
GB2211053B
Cited
US4979170A
Cited
US5111535A
Cited
US5483676A
Cited
US4995083A
Cited
US4984247A
Cited
US5097484A
Cited
US4953197A
Cited
US5022046A
Cited
US5042050A
Cited
US5200956A
Cited
US5117423A
Cited
US5042082A
Cited
US5109393A
Cited
US5022047A
Cited
US5016255A
Cited
US5101501A
Cited
US5056109A
Cited
US5267262A
Cited
US5265119A
Cited
US5109390A
Cited
US5257283A
Cited
US5029184A
Cited
US5073900A
Cited
US5025452A
Cited
US5018165A
Cited
US5166929A
Cited
US5103459B1
Cited
US5103459A
Cited
US5278835A
Cited
US5454028A
Cited
US5455822A
Cited
US5093840A
Cited
US5170412A
Cited
US5107225A
Cited
US5263045A
Cited
US5299198A
Cited
US5274665A
Cited
US5402413A
Cited
US5363373A
Cited
US5291516A
Cited
US5289497A
Cited
US5177765A
Cited
US5177766A
Cited
US5414796A
Cited
US5210771A
Cited
US5410568A
Cited
US5392287A
Cited
US5398247A
Cited
US5430760A
Cited
US5313457A
Cited
US5363368A
Cited
US5263047A
Cited
US5303287A
Cited
US5434859A
Cited
US5506837A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-05-13 | 2005-11-12 | 2006-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-05-13 | 2009-11-12 | 2010-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-05-13 | 2013-11-12 | 2014-05-14 | $7700.00 | Window Closed / Lapsed |