Methods and apparatus of improving inter-sector and/or inter-cell handoffs in a multi-carrier wireless communications system
First Claim
1. A method of operating a first base station transmitter, the method comprising:
- i) operating the first base station transmitter to transmit into a first frequency band during a first period of time during which said first base station transmitter does not transmit into a second frequency band;
ii) operating the first base station transmitter to transmit into a second frequency band during a second period of time which is shorter than said first period of time, said first base station transmitting into said second frequency band for a period of time which is less than 1/N the period of time it transmits into said first frequency band, where N is a positive value greater than 2, transmitting into the second frequency band during the second period of time including concentrating at least 60 percent of the transmitted power on one or more tones occupying less than one fifth of the second frequency band; and
iii) repeating steps i and ii.
3 Assignments
0 Petitions
Accused Products
Abstract
A wireless communications system, e.g., an OFDM system, uses a plurality of carrier frequencies each with an associated frequency band. A base station sector transmitter in the system transmits ordinary signaling, e.g., user data, in its own assigned band. In addition the sector base station transmitter periodically transmits beacon signals into its own frequency band and the frequency bands used by adjacent sector transmitters for their ordinary signaling. Beacon signals, being short duration high power signals with sector transmission power concentrated on one or a few tones, are easily detectable. Each beacon signal may be identified as to the source base station sector transmitter, e.g., based on tone. A mobile node, tuned to a single carrier band, receives a plurality of beacon signals, identifies the sources of the received beacons, compares the received strength of the beacons, and makes handoff decisions, without having to switch carrier band.
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Citations
40 Claims
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1. A method of operating a first base station transmitter, the method comprising:
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i) operating the first base station transmitter to transmit into a first frequency band during a first period of time during which said first base station transmitter does not transmit into a second frequency band; ii) operating the first base station transmitter to transmit into a second frequency band during a second period of time which is shorter than said first period of time, said first base station transmitting into said second frequency band for a period of time which is less than 1/N the period of time it transmits into said first frequency band, where N is a positive value greater than 2, transmitting into the second frequency band during the second period of time including concentrating at least 60 percent of the transmitted power on one or more tones occupying less than one fifth of the second frequency band; and iii) repeating steps i and ii. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of operating a first base station transmitter, the method comprising:
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i) operating the first base station transmitter to transmit into a first frequency band during a first period of time during which said first base station transmitter does not transmit into a second frequency band; ii) operating the first base station transmitter to transmit into a second frequency band during a second period of time which is shorter than said first period of time, said first base station transmitting into said second freouency band for a period of time which is less than 1/N the period of time it transmits into said first frecuency band, where N is a positive value greater than 2, operating the first base station transmitter to transmit into a second frecuency band during a second period of time including transmitting a tone with at least 20 times the average per tone power used to transmit tones in a preceding 1 second time interval; and iii) repeating steps i and ii.
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17. A method of operating a first base station transmitter, the method comprising:
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i) operating the first base station transmitter to transmit into a first frequency band during a first period of time during which said first base station transmitter does not transmit into a second frequency band, said first base station transmitter transmitting user data into said first frequency band on a plurality of different tones during said first period of time; ii) operating the first base station transmitter to transmit into a second frequency band during a second period of time which is shorter than said first period of time, said first base station transmitting into said second frequency band for a period of time which is less than 1/N the period of time it transmits into said first frequency band, where N is a positive value greater than 2, said first base station transmitting transmitter information but no user specific data into said second frequency band during said second period of time, said transmitter information being transmitted using at least one tone, said first transmitter transmitting at least M times the amount of power on said at least one tone than the transmitter transmits on any one tone used to transmit user data during said first period of time into said first frequency band, where M is a positive integer greater than 2; and iii) repeating steps i and ii. - View Dependent Claims (18)
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19. A method of operating a first base station transmitter, the method comprising:
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i) operating the first base station transmitter to transmit into a first frequency band during a first period of time during which said first base station transmitter does not transmit into a second frequency band, said first base station transmitter transmitting user data into said first frequency band on a plurality of different tones during said first period of time; ii) operating the first base station transmitter to transmit into a second frequency band during a second period of time which is shorter than said first period of time, said first base station transmitting into said second frequency band for a period of time which is less than 1/N the period of time it transmits into said first frequency band, where N is a positive value greater than 2, said first base station transmitting transmitter information but no user specific data into said second frequency band during said second period of time, said transmitter information being transmitted using at least one tone, said first transmitter transmitting said at least one tone using at least 20 times the average per tone power used to transmit tones during a preceding 1 second time interval; and iii) repeating steps i and ii.
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20. A method of operating a first base station transmitter, the method comprising:
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i) operating the first base station transmitter to transmit into a first frequency band during a first period of time during which said first base station transmitter does not transmit into a second frequency band; ii) operating the first base station transmitter to transmit into a second frequency band during a second period of time which is shorter than said first period of time, said first base station transmitting into said second frequency band for a period of time which is less than 1/N the period of time it transmits into said first frequency band, where N is a positive value greater than 2; iii) operating a second base station transmitter to transmit into said second frequency band during a third period of time during which said second base station transmitter does not transmit into said first frequency band; iv) operating the second base station transmitter to transmit into said first frequency band during a fourth period of time which is shorter than said third period of time, said second base station transmitter transmitting into said first frequency band for a period of time which is less than 1/N the period of time the second base station transmitter transmits into said second frequency band; and v) repeating steps i, ii, iii and iv. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27)
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28. A communications system, comprising:
a first base station, said first base station including; transmitter information; a first transmitter for transmitting signals into first and second frequency bands; and first transmitter control means for controlling said first transmitter to; i) transmit into a first frequency band during a first period of time during which said first base station transmitter does not transmit into a second frequency band; ii) transmit at least some of said transmitter information without transmitting any user data into a second frequency band during a second period of time, said second period of time being at least less than one fifth said first period of time, less than 4 signal tones are transmitted into said second frequency band by said first transmitter during said second time period, and;
wherein the signal tones transmitted into said second frequency band are transmitted with at least twice the maximum power used to transmit user data into said first frequency band during said first time period andiii) repeat the sequence of steps i and ii at periodic intervals. - View Dependent Claims (29, 30, 31, 32, 33, 34)
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35. A communications system, comprising:
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a first base station, said first base station including; a first transmitter for transmitting signals into first and second frequency bands; and first transmitter control means for controlling said first transmitter to; i) transmit into a first frequency band during a first period of time during which said first base station transmitter does not transmit into a second frequency band; ii) transmit into a second frequency band during a second period of time, said second period of time being at least less than one fifth said first period of time; and iii) repeat the sequence of steps i and ii at periodic intervals; and a second transmitter for transmitting signals into said first and second frequency bands; and second transmitter control means for controlling said second transmitter to; iii) transmit into said second frequency band during a third period of time during which said second base station transmitter does not transmit into said first frequency band; iv) transmit into said first frequency band during a fourth period of time which is shorter than said third period of time, said second transmitter transmitting into said first frequency band for a period of time which is less than 1/N the period of time the second transmitter transmits into said second frequency band; and v) repeat steps iii and iv. - View Dependent Claims (36, 37, 38, 39, 40)
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Specification