Method and system for synchronizing the transmission of digital data while providing variable length filler code

Claim 3

The system of claim 1 further comprising a receiver receiving the transmission words and including: an input shift register receiving said transmission words; decoder network means responsive to the contents of said shift register for decoding said transmission words back into the original source words; and a filler/synchronization detector responsive to the contents of said shift register for controlling said decoder network means to discontinue generating output source words when said filler/synchronization word is detected in said input shift register of said receiver.

Claim 4

The system of claim 1 wherein said circuit means further comprises means for generating said filler/synchronization word having an indefinite number of ZEROS with a minimum at least one more than the longest run of ZEROS that can occur with any combination of two transmittable input words, the maximum number of ZEROS thereof being indefinite and dependent upon the reception of additional input words for encoding, said circuit means terminating each filler/synchronization sequence with a ONE.

Claim 5

The system of claim 1 wherein said statistical source code is a Huffman code which includes a dummy word assigned the all ZEROS sequence whereby all transmittable words have at least one ONE to thereby limit the number of ZEROS in the longest run of consecutive ZEROS for any combination of transmittable words.

Claim 6

The system of claim 1 further comprising synchronization word generator means for controlling said encoder means to generate said filler/synchronization word to re-synchronize a receiver with the transmitter.

Claim 7

In a system for transmitting statistical source code wherein input words of equal length are assigned transmission code words of unequal length based upon the probability of occurrence of the input words and all transmittable code words contain at least one ONE, the combination comprising: transmitter means incluDing an input buffer memory means for storing said input words as they occur; fixed length to variable length encoder means for encoding the words in said input buffer memory means into transmission words according to the assigned code; output means receiving transmission words from said encoding means for coupling said transmission words to a data channel; circuit means responsive to the presence of said input words and said input buffer means for signalling said encoder means to generate a filler/synchronization word having a plurality of ZEROS including at least one more ZERO than the maximum run of ZEROS that can occur with any combination of two transmittable input words, followed by a ONE, whereby said filler/synchronization word is transmitted when said input buffer means contains no more input words; receiver means receiving the code transmitted through said data channel and including input register means for temporarily storing said transmitted code; decoder network means in synchronization with the received data for decoding the transmission words in said input register means to generate output words of length equal to said source words; and filler/synchronization detector means for sensing the presence of said filler/synchronization word in said input register means to inhibit the operation of said decoder means when the same is sensed and to re-synchronize said decoder means upon the occurrance of subsequent transmission words.

Claim 8

In a system for transmitting statistical source code wherein input words of equal length are assigned transmission code words of unequal length based upon the probability of occurrence of the input words and all transmittable code words contain at least one ONE, the combination comprising: transmitter means incluDing an input buffer memory means for storing said input words as they occur; fixed length to variable length encoder means for encoding the words in said input buffer memory means into transmission words according to the assigned code; output means receiving transmission words from said encoding means for coupling said transmission words to a data channel; circuit means responsive to the presence of said input words and said input buffer means for signalling said encoder means to generate a filler/synchronization word having a plurality of ZEROS including at least one more ZERO than the maximum run of ZEROS that can occur with any combination of two transmittable input words, followed by a ONE, whereby said filler/synchronization word is transmitted when said input buffer means contains no more input words; receiver means receiving the code transmitted through said data channel and including input register means for temporarily storing said transmitted code; decoder network means in synchronization with the received data for decoding the transmission words in said input register means to generate output words of length equal to said source words; and filler/synchronization detector means for sensing the presence of said filler/synchronization word in said input register means to inhibit the operation of said decoder means when the same is sensed and to re-synchronize said decoder means upon the occurrance of subsequent transmission words.