Encoding device and method and corresponding decoding device and method

An encoding method for encoding an information bit sequence, the encoding method comprising:

• dividing, by a sequence partitioning entity, the information bit into L information bit sub-sequences, wherein L is an integer greater than or equal to two;
• encoding the L information bit sub-sequences by an encoding entity set, wherein the encoding entity set comprises L encoding entities;
• encoding one information bit sub-sequence of the L sub-sequences, by each encoding entity of the encoding entity set, to generate a respective encoded sub-sequence;
• and
• encoding the respective information bit sub-sequence, by each encoding entity of the encoding entity set, by use of a respective code rate which is determined for transmission via a channel, wherein more than two devices execute transmissions concurrently via the channel;
• generating, by a bitmapping entity, a codeword by mapping one or more encoded bits of each of the encoded sub-sequences to a codeword symbol;
• and
• generating, by a codeword processing entity, an output codeword by processing the codeword for a non-orthogonal multiple access.

A decoding device arranged to decode output codewords received from two or more user devices via a same channel, wherein each user device of the two or more user devices transmits respective output codewords via the channel concurrently, wherein the decoding device comprises:

• a multi-user detecting entity set, comprising L multi-user detecting entities, wherein L is an integer greater than or equal to two;
• and
• a decoding entity set, comprising L decoding entities;
• wherein the decoding device is a multi-level decoding device comprising L levels;
• wherein each level of the decoding device comprises one multi-user detecting entity of the multi-user detecting entity set and one decoding entity of the decoding entity set;
• wherein an encoding entity of the encoding entity set is located between two levels of the decoding device;
• and
• wherein for each user device of two or more user devices concurrently transmitting the respective output codewords via the channel, each multi-user detecting entity of the multi-user detecting entity set is configured to:
• detect an encoded bit sequence from an output codeword transmitted from the respective user device via the channel;
• for each i-th bit of each of symbols of the output codeword, determine a log likelihood ratio and add the log likelihood ratio of the respective i-th bit to a log likelihood ratio set, wherein i corresponds to a level, in which the multi-user detecting entity is located;
• and
• provide the encoded bit sequence and the log likelihood ratio set to a decoding entity of the decoding entity set, which is in the same level as the multi-user detecting entity;
• wherein each decoding entity of the decoding entity set is configured to generate, for each user device of two or more user devices, a decoded information bit sequence by decoding the encoded bit sequence of the respective user device, by using the log likelihood ratio set;
• and
• wherein for each user device of the two or more user devices, each encoding entity of the encoding entity set is configured to:
• receive from a decoding entity of the decoding entity set the decoded information bit sequence of the respective user device;
• generate an encoded information bit sequence from the decoded information bit sequence;
• and
• provide the encoded information bit sequence to a multi-user detecting entity of the multi-user detecting entity set, wherein the level of the multi-user detecting entity is a subsequent level of the level of the decoding entity.