Method and system for synchronizing time-division-duplexed transceivers
First Claim
1. A method for adjusting an alignment for a first transceiver to receive frames of data transmitted from a second transceiver over a transmission medium to the first transceiver, the first transceiver and the second transceiver being associated with a data transmission system providing two-way data communication using time division duplexing, said method comprising the acts of:
- measuring an energy amount for each of a plurality of consecutive frames of received data;
detecting an edge in the plurality of consecutive frames of the received data based on the measured energy amounts, the edge detected being a burst edge, said detecting including at least the acts of;
computing successive energy differences in the plurality of the measured energy amounts; and
identifying a largest one of the successive energy differences, the largest one of the successive energy difference corresponding to the burst edge; and
determining an alignment error estimate using the edge detected in the plurality of consecutive frames.
1 Assignment
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Accused Products
Abstract
An improved techniques for synchronizing transmissions and receptions of a data transmission system utilizing time division duplexing is disclosed. The improved synchronization techniques utilize the time-varying nature of the energy of the received data to obtain synchronization. In one embodiment, the improved synchronization technique uses the output signals from a multicarrier modulation unit (FFT unit) and thus provides the ability to avoid frequency tones that are susceptible to RF interference. The improved synchronization techniques can also utilize crosstalk interference levels to obtain synchronization. Remote receivers in the data transmission system are able to synchronize to central transmitters, central receivers in the data transmission system are able to synchronize to remote transmitters, and central transmitters are able to synchronize with one another.
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Citations
24 Claims
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1. A method for adjusting an alignment for a first transceiver to receive frames of data transmitted from a second transceiver over a transmission medium to the first transceiver, the first transceiver and the second transceiver being associated with a data transmission system providing two-way data communication using time division duplexing, said method comprising the acts of:
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measuring an energy amount for each of a plurality of consecutive frames of received data; detecting an edge in the plurality of consecutive frames of the received data based on the measured energy amounts, the edge detected being a burst edge, said detecting including at least the acts of; computing successive energy differences in the plurality of the measured energy amounts; and identifying a largest one of the successive energy differences, the largest one of the successive energy difference corresponding to the burst edge; and determining an alignment error estimate using the edge detected in the plurality of consecutive frames. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for adjusting an alignment for a first transceiver to receive frames of data transmitted from a second transceiver over a transmission medium to the first transceiver, the first transceiver and the second transceiver being associated with a data transmission system providing two-way data communication using time division duplexing, the first transceiver uses a frame boundary pointer to identify a beginning of a frame in the superframe being received, said method comprising the acts of:
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measuring an energy amount for each of a plurality of consecutive frames of received data; detecting an edge in the plurality of consecutive frames of the received data based on the measured energy amounts; determining an alignment error estimate using the edge detected in the plurality of consecutive frames; and adjusting the frame boundary pointer in accordance with the alignment error estimate. - View Dependent Claims (11, 12, 13)
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14. A method for adjusting an alignment for a first transceiver to receive frames of data transmitted from a second transceiver over a transmission medium to the first transceiver, the first transceiver and the second transceiver being associated with a data transmission system providing two-way data communication using time division duplexing, the data transmission system transmits data using a superframe structure having a plurality of frames, a first set of the frames in the superframe transmit data in a first direction, a second set of the frames in the superframe transmit data in a second direction, and some of the frames contain a cyclic prefix for the superframe structure, said method comprising the acts of:
(a) measuring an energy amount for each of a plurality of consecutive frames of received data, said measuring (a) of the energy amounts including at least the acts of; measuring energy amounts of a first set of consecutive frames of received data for the superframe structure; measuring energy amounts of a second set of consecutive frames of received data for the superframe structure, the second set of the consecutive frames being offset from and overlapped with the first set of the consecutive frames; and combining together the energy amounts from respective consecutive frames from the first and second sets of the consecutive frames to produce the energy amounts; and (b) detecting an edge of the superframe structure within the plurality of consecutive frames of received data using the measured energy amounts. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A computer readable medium containing program instructions for adjusting an alignment for a first transceiver to receive frames of data transmitted from a second transceiver over a transmission medium to the first transceiver, the first transceiver and the second transceiver being associated with a data transmission system providing two-way data communication using time division duplexing, said computer readable medium comprising:
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first computer readable code devices for measuring an energy amount for each of a plurality of consecutive frames of received data; and second computer readable code devices for computing an alignment error estimate using the measured energy amounts, said second computer readable code devices including at least; computer readable code devices for detecting an edge in the plurality of consecutive frames of the received data based on the measured energy amounts, said computer readable code devices for detecting the edge including at least computer readable code devices for computing successive energy differences in the plurality of the measured energy amounts, and computer readable code devices for identifying a largest one of the successive energy differences, the largest one of the successive energy difference corresponding to a burst edge; and computer readable code devices for determining the alignment error estimate using the edge detected in the plurality of consecutive frames. - View Dependent Claims (21)
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22. A computer readable medium containing program instructions for adjusting an alignment for a first transceiver to receive frames of data transmitted from a second transceiver over a transmission medium to the first transceiver, the first transceiver and the second transceiver being associated with a data transmission system providing two-way data communication using time division duplexing, the data transmission system transmits data using a superframe structure having a plurality of frames, some of the frames transmit data in a first direction, some of the frames transmit data in a second direction, and some of the frames contain a cyclic prefix for the superframe structure, said computer readable medium comprising:
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first computer readable code devices for measuring an energy amount for each of a plurality of consecutive frames of received data, said second computer readable code devices including at least; computer readable code for measuring energy amounts of a first set of consecutive frames of received data for the superframe structure; computer readable code for measuring energy amounts of a second set of consecutive frames of received data for the superframe structure, the second set of the consecutive frames being offset from and overlapped with the first set of the consecutive frames; and computer readable code for combining together the energy amounts from respective consecutive frames from the first and second sets of the consecutive frames to produce the energy amounts for said second computer readable code devices; and second computer readable code devices for computing an alignment error estimate using the measured energy amounts, said second computer readable code devices including at least; computer readable code devices for detecting an edge in the plurality of consecutive frames of the received data based on the measured energy amounts; and computer readable code devices for determining the alignment error estimate using the edge detected in the plurality of consecutive frames. - View Dependent Claims (23, 24)
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Specification