# US 2014/0157093 A1 · Method and device for improving decoding of data received from one source by several receivers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0157093 A1 - Document ID: US20140157093A1 - Status: Published application - Kind: A1 - Application number: 14/092,555 - Filed: 2013-11-27 - Published: 2014-06-05 - Earliest claimed: 2012-12-03 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Mounir Achir; Philippe Le Bars - Web page: https://patentgrep.com/patent/US20140157093A1 ## CPC - H03M 13/1128: {Judging correct decoding and iterative stopping criteria other than syndrome check and upper limit for decoding iterations} - H03M 13/1102: {Codes on graphs and decoding on graphs, e.g. low-density parity check [LDPC] codes} - H03M 13/1111: {Soft-decision decoding, e.g. by means of message passing or belief propagation algorithms} - H03M 13/3761: {using code combining, i.e. using combining of codeword portions which may have been transmitted separately, e.g. Digital Fountain codes, Raptor codes or Luby Transform [LT] codes} - H03M 13/3769: {using symbol combining, e.g. Chase combining of symbols received twice or more} - H03M 13/3776: {using a re-encoding step during the decoding process} - H03M 13/6306: {Error control coding in combination with Automatic Repeat reQuest [ARQ] and diversity transmission, e.g. coding schemes for the multiple transmission of the same information or the transmission of incremental redundancy (H03M13/3761, H03M13/3769 and H03M13/635 take precedence)} - H03M 13/05: using block codes, i.e. a predetermined number of check bits joined to a predetermined number of information bits {(H03M13/2906 takes precedence)} - H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C) ## Abstract Improving decoding of a set of k data symbols received from several receivers, the data symbols being encoded by a systematic block error correcting code of dimension k and size n. The set of data symbols is received along with a corresponding subset of parity symbols, forming a partial data block comprising m symbols. A partial data block transmitted by one emitter, comprising a set of k data symbols and a subset of (m−k) parity symbols, is received from each receiver. For each received partial data block, a subset of parity symbols is generated and an item of reliability information is computed as a function of the received parity symbols and parity symbols generated from a received set of data symbols. The items of computed reliability information are compared with each other to select one received set of data bits. ## Claims ### Claim 1 A method for improving decoding of at least one set of k data symbols received from a plurality of receivers, the data symbols being encoded by a systematic block error correcting code of dimension k and size n, k being smaller than n, the set of data symbols being received along with a corresponding subset of parity symbols, forming a partial data block comprising m symbols, m being smaller than n, the method comprising: receiving, from each receiver of a plurality of receivers, a partial data block transmitted by one emitter, the received partial data block comprising a set of k data symbols and a subset of (m−k) parity symbols; for each received partial data block, generating at least a subset of parity symbols from the received set of data symbols; computing an item of reliability information as a function of at least the received parity symbols and parity symbols generated from a received set of data symbols; comparing the items of computed reliability information with each other; and selecting one received set of data bits as a function of comparing the items. ### Claim 2 (depends on 1) The method of claim 1, wherein computing an item of reliability information as a function of at least the received parity symbols and generated parity symbols comprises comparing the received subset of parity symbols with the corresponding subset of generated parity symbols. ### Claim 3 (depends on 2) The method of claim 2, wherein comparing the received subset of parity symbols with the corresponding subset of generated parity symbols comprises computing a distance between the parity symbols of the received subset and of the corresponding subset of generated parity symbols. ### Claim 4 (depends on 3) The method of claim 3, wherein the selected received set of data symbols is the received set of data symbols corresponding to the smallest distance between the parity symbols of the received subset and of the corresponding subset of generated parity symbols. ### Claim 5 (depends on 1) The method of claim 1, wherein a set of (n−k) parity symbols is generated for each received partial data block and wherein computing an item of reliability information as a function of at least the received parity symbols and generated parity symbols comprises replacing parity symbols of a generated set of parity symbols by received parity symbols to obtain a modified set of parity symbols, the item of reliability information being computed as a function of at least the modified set of parity symbols and the received data symbols. ### Claim 6 (depends on 5) The method of claim 5, wherein computing an item of reliability information as a function of at least the received parity symbols and generated parity symbols comprises computing a product of a parity check matrix and a vector resulting from the concatenation of the received data symbols and the modified set of parity symbols. ### Claim 7 (depends on 1) The method of claim 1, wherein computing an item of reliability information as a function of at least the received parity symbols and parity symbols generated from a received set of data symbols comprises computing the item of reliability information as a function of at least the received parity symbols and parity symbols generated from data symbols of the partial data block being processed. ### Claim 8 (depends on 1) The method of claim 1 further comprising: receiving, in at least one receiver of the plurality of receivers, a data block comprising the set of k data symbols and a set of (n−k) parity symbols; and selecting the subset of (m−k) parity symbols from among the received set of (n−k) parity symbols. ### Claim 9 (depends on 8) The method of claim 8 further comprising transmitting the partial data block from the at least one receiver to a controller, the controller carrying the receiving of, from each receiver of a plurality of receivers, a partial data block transmitted by one emitter, the received partial data block comprising a set of k data symbols and a subset of (m−k) parity symbols. ### Claim 10 (depends on 1) The method of claim 1, wherein the systematic block error correcting code is of the Low-Density Parity-Check type. ### Claim 11 (depends on 1) A computer readable medium storing instructions that, when executed by one or more computing devices, cause the one or more computing devices to perform the method according to claim 1. ### Claim 12 An apparatus for improving decoding of at least one set of k data symbols received from a plurality of receivers, the data symbols being encoded by a systematic block error correcting code of dimension k and size n, k being smaller than n, the set of data symbols being received along with a corresponding subset of parity symbols, forming a partial data block comprising m symbols, m being smaller than n, the apparatus comprising: receiving means for receiving, from each receiver of a plurality of receivers, a partial data block transmitted by one emitter, the received partial data block comprising a set of k data symbols and a subset of (m−k) parity symbols; processing means for processing each received partial data block, the processing means being configured for executing generating at least a subset of parity symbols from the received set of data symbols, and computing an item of reliability information as a function of at least the received parity symbols and parity symbols generated from a received set of data symbols; comparing means for comparing the items of computed reliability information with each other; and selecting means for selecting one received set of data bits as a function of comparing the items of computed reliability information with each other. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein the processing means are further configured so that computing an item of reliability information as a function of at least the received parity symbols and generated parity symbols comprises comparing the received subset of parity symbols with the corresponding subset of generated parity symbols. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the processing means are further configured so comparing the received subset of parity symbols with the corresponding subset of generated parity symbols comprises computing a distance between the parity symbols of the received subset and of the corresponding subset of generated parity symbols. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein the selected received set of data symbols is the received set of data symbols corresponding to the smallest distance between the parity symbols of the received subset and of the corresponding subset of generated parity symbols. ### Claim 16 (depends on 12) The apparatus of claim 12, wherein the processing means are configured to generate a set of (n−k) parity symbols for each received partial data block and are configured so computing an item of reliability information as a function of at least the received parity symbols and generated parity symbols comprises replacing parity symbols of a generated set of parity symbols by received parity symbols to obtain a modified set of parity symbols, the item of reliability information being computed as a function of at least the modified set of parity symbols and the received data symbols. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the processing means are configured so that computing an item of reliability information as a function of at least the received parity symbols and generated parity symbols comprises computing a product of a parity check matrix and a vector resulting from the concatenation of the received data symbols and the modified set of parity symbols. ### Claim 18 (depends on 12) The apparatus of claim 12, wherein the processing means are configured so that computing an item of reliability information as a function of at least the received parity symbols and parity symbols generated from a received set of data symbols comprises computing the item of reliability information as a function of at least the received parity symbols and parity symbols generated from data symbols of the partial data block being processed. ### Claim 19 (depends on 12) The apparatus of claim 12 further comprising: second receiving means for receiving, in at least one receiver of the plurality of receivers, a data block comprising the set of k data symbols and a set of (n−k) parity symbols; and second selecting means for selecting the subset of (m−k) parity symbols from among the received set of (n−k) parity symbols. ### Claim 20 (depends on 19) The apparatus of claim 19 further comprising transmitting means for transmitting the partial data block from the at least one receiver to a controller, the controller comprising means for receiving, from each receiver of a plurality of receivers, a partial data block transmitted by one emitter, the received partial data block comprising a set of k data symbols and a subset of (m−k) parity symbols.