Digital word synchronizing arrangement

Claim 2

An improved arrangement for achieving synchronization with a data message comprising a synchronizing word transmitted a plurality of times during said message in a communication system in which said data message is not analyzed until after achieving said synchronization, comprising: a. input means for receiving said transmitted synchronizing words; b. means for storing a predetermined synchronizing word; c. means coupled to said input means and to said storing means for comparing each received synchronizing word with said stored synchronizing word, and producing a first signal in response to each received synchronizing word that corresponds to said stored synchronizing word; and d. in-synchronization signal generating means coupled to said comparing means for producing an in-sychronization signal in response to one of said first signals followed by the production of at least two more of said first signals during any sequence of any of the next four comparisons of said received synchronizing words with said stored predetermined synchronizing word even when a first signal is not produced during each of two consecutive comparisons, whereby data message analysis is initiated in response to said in-synchronization signal.

Claim 3

The improved arrangement of claim 1 wherein said transmitted synchronizing words are spaced at uniform intervals during said message, and wherein said comparing means makes said next four comparisons at said uniform intervals.

Claim 4

The improved arrangement of claim 1 wherein said transmitted synchronizing words are spaced at predetermined intervals during said message, and wherein said comparing means makes said next four comparisons at said predetermined intervals.

Claim 5

For use in a communication system having at least a transmitter at a first location and a receiver at a second location for receiving digital messages including digital data from said transmitter, said digital data being analyzed in response to said receiver achieving synchronization with said digital messages, synchronizing apparatus comprising: a. means coupled to said receiver for deriving digital messages therefrom, each derived digital message having a plura1ity of synchronizing words occurring at locations therein which are spaced at predetermined intervals; b. means coupled to said deriving means for producing a synchronizing signal in response to each derived synchronizing word having a predetermined sequence of digital values; c. counting means coupled to said deriving means for counting said synchronizing word locations, and coupled to said producing means for counting said synchronizing signals; and d. in-synchronization signal generating means coupled to said counting means for producing an in-synchronization output signal in response to at least two synchronizing signals during any sequence of any of the next four counted synchronizing word locations following the production of the first synchronizing signal during a digital message even when a synchronizing word is not detected at each of two consecutive synchronizing word locations, whereby data message analysis is initiated in response to said generated output in-synchronization signal.

Claim 6

For use in a communication system having at least a transmitter at a first location and a receiver at a second location for receiving digital messages including digital data from said transmitter, said digital data being analyzed in response to said receiver achieving synchronization with said digital messages, synchronizing apparatus comprising: a. means coupled to said receiver for deriving digital messages therefrom, each derived digital message having a plura1ity of synchronizing words occurring at locations therein which are spaced at predetermined intervals; b. means coupled to said deriving means for producing a synchronizing signal in response to each derived synchronizing word having a predetermined sequence of digital values; c. counting means coupled to said deriving means for counting said synchronizing word locations, and coupled to said producing means for counting said synchronizing signals; and d. in-synchronization signal generating means coupled to said counting means for producing an in-synchronization output signal in response to at least two synchronizing signals during any sequence of any of the next four counted synchronizing word locations following the production of the first synchronizing signal during a digital message even when a synchronizing word is not detected at each of two consecutive synchronizing word locations, whereby data message analysis is initiated in response to said generated output in-synchronization signal.

Claim 7

The synchronizing apparatus of claim 4 wherein said digital message has a plurality of identical synchronizing words occurring at locations therein which are spaced at predetermined equal intervals.

Claim 8

An improved method for detecting a digital synchronizing word comprised of a sequence of digital signals having a predetermined characteristic and appearing at a plurality of spaced predetermined times in a received digital message in a communication system where data in said digital message is analyzed after achieving synchronization with said received digital message, said method comprising the steps of: a. storing a predetermined digital word prior to receiving said digital message; b. comparing said sequence of digital signals with said stored predetermined digital word and producing a first detected word signal in response to the first sequence of digital signals in a message being the same as said stored predetermined digital word; c. comparing said sequence of digital signals with said stored digital word at said predetermined times subsequent to said first detected word signal being produced, and producing a second detected word signal in response to each sequence of digital signals at subsequent predetermined times being the same as said stored digital word; d. counting said second detected word signals subsequent to said first detected word signal; and e. producing an in-synchronization signal in response to a production of at least two detected word signals during any sequence of any of said next four subsequent predetermined times even when a detected word signal is not produced during each of two consecutive comparisons, whereby data message analysis is initiated in response to said generated in-synchronization signal.

Claim 9

An improved method for detecting a digital synchronizing word comprised of a sequence of digital signals having a predetermined characteristic and appearing at a plurality of spaced predetermined times in a received digital message in a communication system where data in said digital message is analyzed after achieving synchronization with said received digital message, said method comprising the steps of: a. storing a predetermined digital word prior to receiving said digital message; b. comparing said sequence of digital signals with said stored predetermined digital word and producing a first detected word signal in response to the first sequence of digital signals in a message being the same as said stored predetermined digital word; c. comparing said sequence of digital signals with said stored digital word at said predetermined times subsequent to said first detected word signal being produced, and producing a second detected word signal in response to each sequence of digital signals at subsequent predetermined times being the same as said stored digital word; d. counting said second detected word signals subsequent to said first detected word signal; and e. producing an in-synchronization signal in response to a production of at least two detected word signals during any sequence of any of said next four subsequent predetermined times even when a detected word signal is not produced during each of two consecutive comparisons, whereby data message analysis is initiated in response to said generated in-synchronization signal.

Claim 10

The improved method of claim 6 and, in the absence of at least two detected word signals during said next four subsequent predetermined times, comparing said sequence of digital signals with said stored digital word until said first detected word signal is produced.

Claim 11

The improved method of claim 6 and, in the absence of two second detected word signals during said four subsequent predetermined times, further comprising the step of resetting the count of detected word signals to zero, and comparing said sequence of digital signals with said stored digital word until said first detected word signal is produced.

Claim 12

An improved arrangement for achieving synchronization with a data message comprising serial bits forming a synchronizing word transmitted a plurality of times during said message in a communication system where data is not analyzed until after achieving said synchronization, comprising: a. input means for receiving said transmitted synchronizing words; b. means for storing a predetermined synchronizing word; c. means coupled to said input means and to said storing means for comparing received serial bits with said stored synchronizing word, and producing an initial signal in response to an initial comparison in which a series of bits correspond to said stored synchronizing word, and producing a good word signal in response to each subsequent comparison in which each series of bits correspond to said stored synchronizing word; and d. in-synchronization signal generating means coupled to said comparing means for producing an in-synchronization signal in response to at least two of said good word signals during any sequence of any of the next four subsequent comparison of said groups of subsequent series of bits with said stored synchronizing word even when a good word signal is not produced during each of two consecutive comparisons, whereby data analysis is initiated in response to said generated in-synchronization signal.

Claim 13

An improved arrangement for achieving synchronization with a data message comprising serial bits forming a synchronizing word transmitted a plurality of times during said message in a communication system where data is not analyzed until after achieving said synchronization, comprising: a. input means for receiving said transmitted synchronizing words; b. means for storing a predetermined synchronizing word; c. means coupled to said input means and to said storing means for comparing received serial bits with said stored synchronizing word, and producing an initial signal in response to an initial comparison in which a series of bits correspond to said stored synchronizing word, and producing a good word signal in response to each subsequent comparison in which each series of bits correspond to said stored synchronizing word; and d. in-synchronization signal generating means coupled to said comparing means for producing an in-synchronization signal in response to at least two of said good word signals during any sequence of any of the next four subsequent comparison of said groups of subsequent series of bits with said stored synchronizing word even when a good word signal is not produced during each of two consecutive comparisons, whereby data analysis is initiated in response to said generated in-synchronization signal.

Claim 14

The improved arrangement of claim 9 wherein said initial comparison is made each time a new bit is received.

Claim 15

The improved arrangement of claim 9 wherein each of said subsequent comparisons is made in response to a synchronizing word position indication.

Claim 16

The improved arrangement of claim 10 wherein each of said subsequent comparisons is made in response to a synchronizing word position indication.

Claim 17

The improved arrangement of claim 9 and comprising means to restart said initial comparison following said next four comparisons of said groups.

Claim 18

The improved arrangement of claim 10 and comprising means to restart said initial comparison following said next four comparisons of said groups.

Claim 19

The improved arrangement of claim 11 and comprising means to restart said initial comparison following said next four comparisons of said groups.

Claim 20

The improved arrangement of claim 12 and comprising means to restart said initial comparison following said next four comparisons of said groups.

Claim 21

An improved method for detecting a digital synchronizing word comprised of a sequence of digital signals having a predetermined characteristic and appearing at a plurality of spaced predetermined times in a digital data message is a communication system in which data in said digital message in not analyzed until after achieving synchronization with said message, said method comprising the steps of: a. initially comparing said sequence of digital signals each time a new signal occurs in said sequence with a stored digital word and producing an initial signal in response to the first sequence of digital signals in a message being the same as said stored digital word; b. subsequently comparing said sequence of digital signals on a time position basis with said stored digital word at said predetermined times subsequent to said initial signal being produced, and producing a second signal in response to each sequence of digital signals at subsequent predetermined times being the same as said stored digital word; c. counting said second signals subsequent to said initial signal; d. producing an in-synchronization signal in response to production of at least two of said second signals during any sequence of any of said next four subsequent predetermined times even when a second signal is not produced during each of two consecutive subsequent predetermined times; and e. starting said initial comparison following said four predetermined times, whereby data analysis is initiated in response to said generated in-synchronization signal.

Claim 22

An improved method for detecting a digital synchronizing word comprised of a sequence of digital signals having a predetermined characteristic and appearing at a plurality of spaced predetermined times in a digital data message is a communication system in which data in said digital message in not analyzed until after achieving synchronization with said message, said method comprising the steps of: a. initially comparing said sequence of digital signals each time a new signal occurs in said sequence with a stored digital word and producing an initial signal in response to the first sequence of digital signals in a message being the same as said stored digital word; b. subsequently comparing said sequence of digital signals on a time position basis with said stored digital word at said predetermined times subsequent to said initial signal being produced, and producing a second signal in response to each sequence of digital signals at subsequent predetermined times being the same as said stored digital word; c. counting said second signals subsequent to said initial signal; d. producing an in-synchronization signal in response to production of at least two of said second signals during any sequence of any of said next four subsequent predetermined times even when a second signal is not produced during each of two consecutive subsequent predetermined times; and e. starting said initial comparison following said four predetermined times, whereby data analysis is initiated in response to said generated in-synchronization signal.

Claim 27

A method as in claim 19 wherein said searching step includes the step of establishing bit synchronization.