If a configuration is employed in which modulation schemes used for an optical communication system can be switched depending on transmission conditions, it is difficult to make effective utilization of frequency resources without the power consumption increasing and the control becoming complex; therefore, an optical transmitter according to an exemplary aspect of the present invention includes an interface means for converting a digital signal to be transmitted under a predetermined transmission condition over an optical carrier wave into a parallel signal with a predetermined bit number at a predetermined transmission rate, and outputting the parallel signal; an encoding means for encoding the parallel signal using one coding system from among a plurality of convolutional coding systems with different degrees of redundancy; a mapping means for mapping an output bit signal output from the encoding means to a modulation symbol; an optical modulation means for modulating the optical carrier wave based on a symbol signal output from the mapping means; and an encoding control means for selecting a predetermined coding system corresponding to the predetermined transmission condition from among the plurality of convolutional coding systems and controlling the interface means, the encoding means, the mapping means, and the optical modulation means in such a way as to operate in accordance with the predetermined coding system.

If a configuration is employed in which modulation schemes used for an optical communication system can be switched depending on transmission conditions, it is difficult to make effective utilization of frequency resources without the power consumption increasing and the control becoming complex; therefore, an optical transmitter according to an exemplary aspect of the present invention includes an interface means for converting a digital signal to be transmitted under a predetermined transmission condition over an optical carrier wave into a parallel signal with a predetermined bit number at a predetermined transmission rate, and outputting the parallel signal; an encoding means for encoding the parallel signal using one coding system from among a plurality of convolutional coding systems with different degrees of redundancy; a mapping means for mapping an output bit signal output from the encoding means to a modulation symbol; an optical modulation means for modulating the optical carrier wave based on a symbol signal output from the mapping means; and an encoding control means for selecting a predetermined coding system corresponding to the predetermined transmission condition from among the plurality of convolutional coding systems and controlling the interface means, the encoding means, the mapping means, and the optical modulation means in such a way as to operate in accordance with the predetermined coding system.

Provided are a data checking method and device. The method includes: receiving a transmission signal containing a first data block and transmitted by a transmission node, wherein the length of the first data block is N bits, the first data block is generated by performing an FEC encoding on a second data block which has a length of K bits, and the second data block is generated by performing a CRC encoding on a third data block which has a length of L bits, where N, K and L are all positive integers, and N≧K>L; obtaining a first estimation data block of the first data block according to the transmission signal, and obtaining a second estimation data block of the second data block according to the transmission signal; and checking the third data block according to a relationship between the first estimation data block and an FEC code space and/or a CRC check result of the second estimation data block. By means of the technical solution provided in the present disclosure, the problems that a transmission rate decreases due to the fact that a CRC check code is too long and a false detection rate cannot be ensured due to the fact that the CRC check code is too short are solved.

A wireless communication device, including a radiofrequency frontend, configured to wirelessly receive a radiofrequency signal; perform one or more analog baseband operations on the received radiofrequency signal, according to a radio access technology; and output an analog signal representing an output of the analog baseband operations on the received radiofrequency signal; an error corrector, configured to perform an error correction operation on the analog signal; and output an error corrected signal in analog domain; and the analog-digital converter, configured to convert the error corrected signal to digital domain.

Certain aspects of the present disclosure relate to techniques and apparatus for increasing decoding performance and/or reducing decoding complexity. An exemplary method generally includes receiving, via a wireless medium, a codeword encoded using a tailless convolutional code (TLCC) with a known start state, evaluating a set of decoding candidate paths through a trellis decoder that originate at the known start state of the TLCC, performing, for each of a plurality of the decoding candidate paths, a back trace from a respective end state to the known start state, and selecting one of the decoding candidate paths based, at least in part, on path metrics generated while performing the back trace. Other aspects, embodiments, and features are also claimed and described.

A codeword is generated based on a segmentation transform and a Polarization-Assisted Convolutional (PAC) code that includes an outer convolutional code and a polar code, and based on separate encoding of respective different segments of convolutionally encoded input bits according to the polar code. Each segment of the respective segments includes multiple bits of the convolutionally encoded input bits for which the separate encoding of the segment is independent of the separate encoding of other segments. Separate decoding may be applied to segments of such a codeword to decode convolutionally encoded input bits corresponding to the separately encoded segments of the convolutionally encoded input bits.

A method for execution by a computing device of a storage network for transferring data includes detecting a shutdown associated with a local flash memory of the storage network. The method further includes determining whether to transfer encoded data slices stored in the local flash memory, wherein a plurality of data segments are dispersed storage error encoded in accordance with distributed data storage parameters to produce pluralities of sets of encoded data slices that include the encoded data slices. When determining to transfer, the method includes determining a group of encoded data slices stored in the local flash memory to transfer, determining at least one storage location for storage of the group of encoded data slices, transferring the group of encoded data slices to the at least one storage location and outputting a transfer message indicating that the group of encoded data slices has been transferred.

A method for sending forward error correction (FEC) configuration information by a sending apparatus in a multimedia system is provided. The method includes sending source FEC configuration information for an FEC source packet to a receiving apparatus, wherein the source FEC configuration information includes information related to an FEC source or repair packet that is sent first among at least one FEC source or repair packet if an FEC source or repair packet block includes the at least one FEC source or repair packet.

An encoder receives a concatenated encoder input block d, splits d into an outer code input array a, and encodes a using outer codes to generate an outer code output array b. The encoder generates, from b, a concatenated code output array x using a layered polarization adjusted convolutional (LPAC) code. A decoder counts layers and carries out an inner decoding operation for a layered polarization adjusted convolutional (LPAC) code to generate an inner decoder decision {tilde over (b)}.sub.i from a concatenated decoder input array y and a cumulative decision feedback ({circumflex over (b)}.sub.1, {circumflex over (b)}.sub.2, . . . , {circumflex over (b)}.sub.i−1). The decoder carries out an outer decoding operation to generate from {tilde over (b)}.sub.i an outer decoder decision â.sub.i, and carries out a reencoding operation to generate a decision feedback {circumflex over (b)}.sub.i from â.sub.i, where the number of layers is an integer greater than one, with a concatenated decoder output block {circumflex over (d)} being generated from outer decoder decisions.

An encoder receives a concatenated encoder input block d, splits d into an outer code input array a, and encodes a using outer codes to generate an outer code output array b. The encoder generates, from b, a concatenated code output array x using a layered polarization adjusted convolutional (LPAC) code. A decoder counts layers and carries out an inner decoding operation for a layered polarization adjusted convolutional (LPAC) code to generate an inner decoder decision {tilde over (b)}.sub.i from a concatenated decoder input array y and a cumulative decision feedback ({circumflex over (b)}.sub.1, {circumflex over (b)}.sub.2, . . . , {circumflex over (b)}.sub.i−1). The decoder carries out an outer decoding operation to generate from {tilde over (b)}.sub.i an outer decoder decision â.sub.i, and carries out a reencoding operation to generate a decision feedback {circumflex over (b)}.sub.i from â.sub.i, where the number of layers is an integer greater than one, with a concatenated decoder output block {circumflex over (d)} being generated from outer decoder decisions.