Method and apparatus for transmitting signals segmentation
A method for transmitting a transport block includes segmenting the transport block into code blocks corresponding in number to a multiple of the number of layers to be used for the transmission of the transport block, attaching a Cyclic Redundancy Check (CRC) to the segmented code blocks, sequentially mapping the code blocks to which the CRC has been attached to at least one layer according to a predetermined mapping rule, and transmitting the code blocks.
1. A method for a transmission device transmitting a transport block, the method comprising:
attaching a first cyclic redundancy check (CRC) to the transport block;
segmenting the first CRC-attached transport block into a specific number of code blocks;
attaching a second CRC to each of the specific number of code blocks;
mapping the second CRC-attached code blocks to first number of layers for initial transmission of the transport block and mapping the second CRC-attached code blocks to a second number of layers for retransmission of the transport block; and
transmitting the layer-mapped code blocks to a reception device,
wherein:
the specific number is a multiple of a least common multiple of the first number and the second number;
the first number and the second number are different from each other;
the second CRC-attached code blocks are mapped to the first number of layers such that each of the first number of layers includes a first number of second CRC-attached code blocks; and
the second CRC-attached code blocks are mapped to the second number of layers such that each of the second number of layers includes a second number of second CRC-attached code blocks.
2. The method according to claim 1 , wherein segmenting the first CRC-attached transport block comprises:
segmenting the first CRC-attached transport block into a first specific number of sub transport blocks, wherein the first specific number corresponds to the least common multiple of the first number and the second number; and
segmenting each of the first specific number of sub transport blocks into a second specific number of code blocks, wherein a product of the first specific number and the second specific number corresponds to the multiple of the least common multiple of the first number and the second number, and
wherein the second specific number of code blocks segmented from one of the first specific number of sub transport blocks are transmitted via one layer during the retransmission of the transport block when the second number is less than the first number.
3. The method according to claim 1 , wherein segmenting the first CRC-attached transport block comprises segmenting the first CRC-attached transport block into code blocks having a specific bit length.
4. The method according to claim 3 , wherein segmenting the first CRC-attached transport block comprises attaching a dummy bit to at least one of the specific number of code blocks such that each of the specific number of code blocks has the specific bit length.
5. The method according to claim 3 , wherein a length of the transport block is set in advance such that no code block having a length less than the specific bit length is generated by segmenting the first CRC-attached transport block.
6. The method according to claim 3 , further comprising padding a medium access control (MAC) protocol data unit (PDU) corresponding to the transport block such that no code block having a length less than the specific bit length is generated by segmenting the first CRC-attached transport block.
7. The method according to claim 1 , wherein the second CRC-attached code blocks are sequentially mapped to the first number of layers or the second number of layers.
8. The method according to claim 1 , wherein transmitting the layer-mapped code blocks comprises:
scrambling and modulating the layer-mapped code blocks;
performing precoding with respect to the scrambled and modulated code blocks; and transmitting the precoded code blocks.
9. A transmission device for transmitting a transport block, the device comprising:
a first cyclic redundancy check (CRC) attacher configured to attach a first CRC to the transport block;
a virtual layer segmenter configured to segment the first CRC-attached transport block into a specific number of code blocks;
a second CRC attacher configured to attach a second CRC to each of the specific number of code blocks;
a layer mapper configured to:
map the second CRC-attached code blocks to a first number of layers for initial transmission of the transport block; and
map the second CRC-attached code blocks to a second number of layers for retransmission of the transport block; and
a transmitter configured to transmit the layer-mapped code blocks to a reception device,
wherein:
the specific number is a multiple of a least common multiple of the first number and the second number,
the first number and the second number are different from each other;
the second CRC-attached code blocks are mapped to the first number of layers such that each of the first number of layers includes a first number of second CRC-attached code blocks; and
the second CRC-attached code blocks are mapped to the second number of layers such that each of the second number of layers includes a second number of second CRC-attached code blocks.
10. The transmission device according to claim 9 , further comprising:
a dummy bit attacher configured to attach a dummy bit to a front or rear of the transport block.