METHOD FOR MESSAGE TRANSMISSION IN HALF-DUPLEX COMMUNICATION CHANNEL Russian patent published in 1999 - IPC

FIELD: communication devices, in particular, transmission of cascade encoding messages with receipt return confirmation. SUBSTANCE: information transmission method involves transmission of cycles, which consist of cascade code blocks, which system part contains block number and number of blocks in cycle. In addition numbers of non-received blocks in cycle are sent to transmitting party. Transmitting party sends additional characters for these blocks, which together with main characters provide code of increased redundancy. When additional characters are exhausted, method involves repetition of transmission of main characters, using principle of synchronous accumulation of characters from several identical transmissions, hence additionally increasing probability of correct information reception. Block of increased redundancy is formed before decoding, when system part of block is unknown. To achieve this, receiving party has last received receipt and last receipt, which has been acknowledged by transmission party by means of alternation of number system of combinations of internal code in comparison to number system used in previous cycle. In case, if number system has not been altered, last received receipt is used; otherwise last receipt is used. Used receipt provides order of additional characters in blocks which reception has not been yet confirmed. Number of block from which cycle blocks are started to be counted, is detected by phasing with respect to receipt reception ending. In case of miss of any number of cycles during reception due to long-term distortions in communication channel, method involves reading both types of cycle duration in order to detect number of cascade code block in any block of any cycle. Transmission of numbers of combinations of internal code used also for detection of block boundaries runs simultaneously with transmission of internal code combinations, thus removing need in transmission of special synchronization signal (phase start signal). EFFECT: increased correction capacity, increased probability of information reception and decreased time for transmission. 9 dwg