US6081567A — Method and apparatus for synchronizing a data com…

Claim 1

Independent Claim 172 words

A synchronization method for use in a data communication system having a first device configured to communicate with a second device over a communication network, said communication network introducing a number of digital impairments to a transmit signal such that said digital impairments arrive at said second device in a periodic manner based on a period of N symbols, said method comprising the steps of: transmitting a plurality of signal segments from said first device to said second device, each of said signal segments being represented by an integer multiple of N symbols; obtaining synchronization with symbols transmitted by said first device, said obtaining step being performed by said second device; determining a symbol position, relative to each of said signal segments where a digital impairment was introduced by said communication network, said determining step being responsive to said obtaining step; and deriving a compensating signal point constellation for use during subsequent encoding and decoding of signal points associated with said symbol position, said deriving step being performed by said second device.

Claim 2

Dependent Claim 172 words

A synchronization method for use in a data communication system having a first device configured to communicate with a second device over a communication network, said communication network introducing a number of digital impairments to a transmit signal such that said digital impairments arrive at said second device in a periodic manner based on a period of N symbols, said method comprising the steps of: transmitting a plurality of signal segments from said first device to said second device, each of said signal segments being represented by an integer multiple of N symbols; obtaining synchronization with symbols transmitted by said first device, said obtaining step being performed by said second device; determining a symbol position, relative to each of said signal segments where a digital impairment was introduced by said communication network, said determining step being responsive to said obtaining step; and deriving a compensating signal point constellation for use during subsequent encoding and decoding of signal points associated with said symbol position, said deriving step being performed by said second device.

Claim 3

Dependent Claim 15 words

A method according to claim 1, wherein said digital impairment comprises robbed bit signaling (RBS).

Claim 4

Dependent Claim 19 words

A method according to claim 1, wherein at least one of said signal segments is a period of silence.

Claim 5

Dependent Claim 8 words

A method according to claim 1, wherein N=6.

Claim 6

Dependent Claim 16 words

A method according to claim 1, wherein said transmitting step transmits signal segments having N symbols.

Claim 7

Dependent Claim 146 words

A synchronization method for use in a data communication system having a first device configured to communicate with a second device over a communication network, said communication network employing robbed bit signaling (RBS) such that symbols affected by RBS arrive at said second device in a periodic manner based on a period of N symbols, said method comprising the steps of: transmitting a plurality of signal segments from said first device to said second device, each of said signal segments being represented by an integer multiple of N symbols; receiving said signal segments at said second device; synchronizing said second device to symbols transmitted by said first device; and initializing a modulo-N symbol counter at said second device in response to receipt of an initial signal segment by said second device, said modulo-N symbol counter being synchronous to a symbol count associated with said signal segments.

Claim 8

Dependent Claim 146 words

A synchronization method for use in a data communication system having a first device configured to communicate with a second device over a communication network, said communication network employing robbed bit signaling (RBS) such that symbols affected by RBS arrive at said second device in a periodic manner based on a period of N symbols, said method comprising the steps of: transmitting a plurality of signal segments from said first device to said second device, each of said signal segments being represented by an integer multiple of N symbols; receiving said signal segments at said second device; synchronizing said second device to symbols transmitted by said first device; and initializing a modulo-N symbol counter at said second device in response to receipt of an initial signal segment by said second device, said modulo-N symbol counter being synchronous to a symbol count associated with said signal segments.

Claim 9

Dependent Claim 60 words

A method according to claim 6, further comprising the steps of: detecting the effect of RBS in at least one of said received signal segments, said detecting step being performed by said second device; and determining at least one symbol position, relative to said at least one of said received signal segments, where RBS was employed by said communication network.

Claim 10

Dependent Claim 38 words

A method according to claim 7, further comprising the step of deriving, for each of said at least one symbol position, a compensating signal point constellation for use during subsequent encoding and decoding of symbols affected by RBS.

Claim 11

Dependent Claim 8 words

A method according to claim 6, wherein N=6.

Claim 12

Dependent Claim 16 words

A method according to claim 6, wherein said transmitting step transmits signal segments having N symbols.

Claim 13

Dependent Claim 34 words

A method according to claim 6, wherein said initializing step initializes said modulo-N symbol counter in response to receipt of a first symbol of a subsequent signal segment that follows said initial signal segment.

Claim 14

Dependent Claim 26 words

A method according to claim 6, wherein said initializing step initializes said modulo-N symbol counter after receipt of a reference-position symbol of said initial signal segment.

Claim 15

Dependent Claim 201 words

A data communication system having a first device configured to transmit signal segments to a second device over a communication network, said communication network introducing a number of digital impairments to a transmit signal such that said digital impairments arrive at said second device in a periodic manner based on a period of N symbols, said data communication system comprising: means for formatting a plurality of signal segments such that each of said signal segments is represented by an integer multiple of N symbols; means for transmitting said plurality of signal segments from said first device to said second device; means for synchronizing said second device to symbols transmitted by said first device; and means for determining at least one symbol position, relative to each of said signal segments, where a digital impairment was introduced by said communication network; wherein: said second device is configured to derive at least one compensating signal point constellation for use during subsequent encoding and decoding of signal points associated with said at least one symbol position; and said first device is configured to employ said at least one compensating signal point constellation in said periodic manner with respect to said at least one symbol position.

Claim 16

Dependent Claim 201 words

A data communication system having a first device configured to transmit signal segments to a second device over a communication network, said communication network introducing a number of digital impairments to a transmit signal such that said digital impairments arrive at said second device in a periodic manner based on a period of N symbols, said data communication system comprising: means for formatting a plurality of signal segments such that each of said signal segments is represented by an integer multiple of N symbols; means for transmitting said plurality of signal segments from said first device to said second device; means for synchronizing said second device to symbols transmitted by said first device; and means for determining at least one symbol position, relative to each of said signal segments, where a digital impairment was introduced by said communication network; wherein: said second device is configured to derive at least one compensating signal point constellation for use during subsequent encoding and decoding of signal points associated with said at least one symbol position; and said first device is configured to employ said at least one compensating signal point constellation in said periodic manner with respect to said at least one symbol position.

Claim 17

Dependent Claim 17 words

A data communication system according to claim 13, wherein said digital impairment comprises robbed bit signaling (RBS).

Claim 18

Dependent Claim 10 words

A data communication system according to claim 13, wherein N=6.

Claim 19

Dependent Claim 22 words

A data communication system according to claim 13, wherein said means for transmitting is configured to transmit signal segments having N symbols.

Claim 20

Dependent Claim 148 words

In a data communication system having a first device configured to transmit data to a second device, a method for compensating for digital impairments in a transmit signal, where said digital impairments arrive at said second device in a periodic manner based on a period of N symbols, said method comprising the steps of: formatting a plurality of signal segments such that each of said signal segments is represented by an integer multiple of N symbols; starting a first symbol counter at said first device upon transmission of a first symbol associated with one of said signal segments; transmitting said signal segments from said first device to said second device; initializing a second symbol counter at said second device after receipt of said first symbol by said second device; and utilizing compensating signal point constellations, in response to said second symbol counter, for symbols affected by digital impairments.

Claim 21

Dependent Claim 148 words

In a data communication system having a first device configured to transmit data to a second device, a method for compensating for digital impairments in a transmit signal, where said digital impairments arrive at said second device in a periodic manner based on a period of N symbols, said method comprising the steps of: formatting a plurality of signal segments such that each of said signal segments is represented by an integer multiple of N symbols; starting a first symbol counter at said first device upon transmission of a first symbol associated with one of said signal segments; transmitting said signal segments from said first device to said second device; initializing a second symbol counter at said second device after receipt of said first symbol by said second device; and utilizing compensating signal point constellations, in response to said second symbol counter, for symbols affected by digital impairments.

Claim 22

Dependent Claim 39 words

A method according to claim 17, further comprising the step of determining at least one symbol position, relative to each of said signal segments, where a digital impairment was introduced, said determining step being responsive to said initializing step.

Claim 23

Dependent Claim 15 words

A method according to claim 17, wherein said digital impairment comprises robbed bit signaling, (RBS).

Claim 24

Dependent Claim 37 words

A method according to claim 17, further comprising the step of selecting a plurality of optimized signal point constellations associated with different states of said second symbol counter, said selecting step being performed by said second device.

Claim 25

Dependent Claim 28 words

A method according to claim 20, further comprising the step of sending information indicative of said optimized signal point constellations from said second device to said first device.

Claim 26

Dependent Claim 16 words

A method according to claim 17, wherein said second symbol counter comprises a modulo-N symbol counter.

Claim 27

Dependent Claim 45 words

A method according to claim 17, wherein: said first symbol is associated with an initial signal segment; and said initializing step initializes said second symbol counter in response to receipt of a first symbol of a subsequent signal segment that follows said initial signal segment.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2003-06-27	2003-12-27	2004-06-27	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2007-06-27	2007-12-27	2008-06-27	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2011-06-27	2011-12-27	2012-06-27	$7700.00	Window Closed / Lapsed

Method and apparatus for synchronizing a data communication system to a periodic digital impairment

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