US3868633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Block coded communication system
Assignee: United States Department of the Navy
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Filing: 1973-12-17
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Granted: 1975-02-25
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Expires: 1993-12-17
Abstract
Abstract A noisy forward communication channel is employed to transfer data which has been symbolically coded and also to transfer correction instructions; a noiseless feedback channel is used to return each symbol as it is received to the sending station. The apparatus transfers binary digital data without excessive redundancy, delay or complexity by correcting transmission errors by means of correction instructions as opposed to retransmitting the entire block of data.
Inventors
- 👤 Carlos Nuese
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:30
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/12; H04L1/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
364 words
Communication apparatus comprising: a sending station; a remote receiving station; said stations being connected to each other by a noisy forward communication channel and by a noiseless feedback communication channel; said sending station comprising means for accepting input data symbols and for converting K of said data symbols into G groups, means for inserting a separator symbol after each of said groups, means for transmitting said G groups of information symbols, said separator symbols, correction symbols and reversal symbols to form a block comprising N total symbols to said receiving sTation by means of said forward channel; said receiving station comprising means for returning each received symbol, as received, to said sending station by means of said feedback channel; said sending station further including means for comparing each returned symbol of said block with the original corresponding symbol transmitted and for producing an error indication each time a difference is detected, up to a maximum of E errors, means responsive to each error indication to provide Q of said correction symbols, means for interrupting the transmission of said G groups and separator symbols after each error is detected and for transmitting said Q correction symbols to said receiving station during each interruption thereof and immediately following each error, means further responsive to the total number of errors, e, occurring in each block for providing (E - e) Q of said reversal symbols if e < E, means for interrupting the transmission of said G groups, separator symbols, and correction symbols and for transmitting said reversal symbols to said receiving station by means of said forward channel, to complete the N symbols of each block and wherein N K + G + EQ; said receiving station further including means responsive to said received blocks to determine if Q successive symbols have the same value thereby indicating the occurrence of an error during transmission, means for replacing each (Q + 1) symbols in which the earliest symbol has one value and the successively received Q symbols have the opposite value with a single value equal to the Q identically-valued symbols, and means for removing said separator symbols from each block thereafter to provide error-free information symbols.
Claim 2
Dependent Claim
364 words
Communication apparatus comprising: a sending station; a remote receiving station; said stations being connected to each other by a noisy forward communication channel and by a noiseless feedback communication channel; said sending station comprising means for accepting input data symbols and for converting K of said data symbols into G groups, means for inserting a separator symbol after each of said groups, means for transmitting said G groups of information symbols, said separator symbols, correction symbols and reversal symbols to form a block comprising N total symbols to said receiving sTation by means of said forward channel; said receiving station comprising means for returning each received symbol, as received, to said sending station by means of said feedback channel; said sending station further including means for comparing each returned symbol of said block with the original corresponding symbol transmitted and for producing an error indication each time a difference is detected, up to a maximum of E errors, means responsive to each error indication to provide Q of said correction symbols, means for interrupting the transmission of said G groups and separator symbols after each error is detected and for transmitting said Q correction symbols to said receiving station during each interruption thereof and immediately following each error, means further responsive to the total number of errors, e, occurring in each block for providing (E - e) Q of said reversal symbols if e < E, means for interrupting the transmission of said G groups, separator symbols, and correction symbols and for transmitting said reversal symbols to said receiving station by means of said forward channel, to complete the N symbols of each block and wherein N K + G + EQ; said receiving station further including means responsive to said received blocks to determine if Q successive symbols have the same value thereby indicating the occurrence of an error during transmission, means for replacing each (Q + 1) symbols in which the earliest symbol has one value and the successively received Q symbols have the opposite value with a single value equal to the Q identically-valued symbols, and means for removing said separator symbols from each block thereafter to provide error-free information symbols.
Claim 3
Dependent Claim
29 words
The apparatus of claim 1 wherein the first group of said G groups includes (Q - 1) information symbols, and each other group includes (Q - 2) information symbols.
Claim 4
Dependent Claim
17 words
The apparatus of claim 2 wherein said separator symbol comprises the inverse of the symbol preceding it.
Claim 5
Dependent Claim
16 words
The apparatus of claim 3 wherein said correction symbols comprise Q repetitions of the original symbol.
Claim 6
Dependent Claim
17 words
The apparatus of claim 4 wherein each reversal symbol comprises the inverse of the symbol preceding it.
Claim 7
Dependent Claim
42 words
The apparatus of claim 1 wherein said means for comparing each returned symbol with the original symbol includes means for storing said original symbol until the returned symbol is received and further including AND logic gate means for producing said error indication.
Claim 8
Dependent Claim
180 words
Digital communication apparatus comprising: a sending station and a receiving station; noisy forward channel means for sending data to said receiving station in blocks containing K information symbols arranged in G groups separated from each other by a separator symbol; noiseless feedback channel means for returning each symbol as it is received to said sending station; error detection and correction means for comparing each returned symbol with the corresponding original symbol and for interrupting the transmission of information and separator symbols each time an error is detected and for transmitting Q correction symbols immediately after each error; error counter means responsive to the total number of errors, e, occurring during each block for interrupting the transmission of information, separator, and correction symbols, if e < E, where E equals the maximum number of corrections possible during each block, and for transmitting (E - e)Q reversal symbols to complete said N symbols in each block where N K + G + EQ; and, means at said receiving station for removing said separator, correction, and reversal symbols to provide said informatiOn symbols.
Claim 9
Dependent Claim
180 words
Digital communication apparatus comprising: a sending station and a receiving station; noisy forward channel means for sending data to said receiving station in blocks containing K information symbols arranged in G groups separated from each other by a separator symbol; noiseless feedback channel means for returning each symbol as it is received to said sending station; error detection and correction means for comparing each returned symbol with the corresponding original symbol and for interrupting the transmission of information and separator symbols each time an error is detected and for transmitting Q correction symbols immediately after each error; error counter means responsive to the total number of errors, e, occurring during each block for interrupting the transmission of information, separator, and correction symbols, if e < E, where E equals the maximum number of corrections possible during each block, and for transmitting (E - e)Q reversal symbols to complete said N symbols in each block where N K + G + EQ; and, means at said receiving station for removing said separator, correction, and reversal symbols to provide said informatiOn symbols.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |