Transmission method, transmitter, reception method, and receiver
In order to transmit a codeword that is generated based on a quasi-cyclic low-density parity-check coding scheme and consists of N cyclic blocks each consisting of Q bits, a bit permutation is applied to the bits of the codeword, a plurality of constellation blocks each consisting of G×M bits are generated, and a block permutation is applied to the constellation blocks. The bit permutation is adopted for each of N/M sections each consisting M cyclic blocks such that the constellation blocks each consist of G×M bits from M distinct cyclic blocks of the associated section. The block permutation is equivalent to writing the constellation blocks into a matrix with R rows and (Q/(k×G)) columns and reading out the constellation blocks column by column from the matrix, where R is k×(N/M), and k is a positive integer.
1. A transmission method for transmitting a codeword generated based on a quasi-cyclic low-density parity-check coding scheme including a repeat-accumulate quasi-cyclic low-density parity-check coding scheme, the codeword consisting of N quasi-cyclic blocks, the quasi-cyclic blocks each consisting of Q bits, the transmission method comprising the steps of:
applying, using a bit interleaver, a bit permutation to the bits of the codeword;
generating, using a generator, a plurality of constellation blocks from the permuted bits of the codeword, each of the plurality of constellation blocks being generated from G×M bits;
applying, using a constellation block interleaver, a constellation block permutation to the constellation blocks; and
transmitting, using a transmission unit, the permuted constellation blocks,
wherein the codeword is divided into N/M sections each consisting of M quasi-cyclic blocks,
the constellation blocks are each associated with one of the sections,
the bit permutation is adapted such that the constellation blocks each consist of G×M bits from M different quasi-cyclic blocks of the associated section, and
the constellation block permutation is equivalent to writing the constellation blocks row by row into a matrix with R rows and (Q/(k×G)) columns and reading out the constellation blocks column by column from the matrix, where R is k×(N/M), and k is a positive integer.
2. The transmission method according to claim 1 , wherein
applying of the bit permutation includes
applying, using a section interleaver included in the bit interleaver, a section permutation to the sections independently of each other so as to permute the bits of each of the sections.
3. The transmission method according to claim 2 , wherein
applying of the section permutation is equivalent to writing the M×Q bits of each of the sections row by row into a matrix with M rows and Q columns and reading out the bits column by column from the matrix.
4. A reception method for receiving a codeword generated based on a quasi-cyclic low-density parity-check coding scheme including a repeat-accumulate quasi-cyclic low-density parity-check coding scheme, the codeword consisting of N quasi-cyclic blocks, the quasi-cyclic blocks each consisting of Q bits, the codeword undergoing predetermined processing and then being transmitted by a transmitter, the predetermined processing including:
a bit permutation of permuting the bits of the codeword;
a generation of generating a plurality of constellation blocks from the permuted bits of the codeword, each of the plurality of constellation blocks being generated from G×M bits; and
a constellation block permutation of permuting the constellation blocks,
wherein the codeword is divided into N/M sections each consisting of M quasi-cyclic blocks,
the constellation blocks are each associated with one of the sections,
the bit permutation is adapted such that the constellation blocks each consist of G×M bits from M different quasi-cyclic blocks of the associated section, and
the constellation block permutation is equivalent to writing the constellation blocks row by row into a matrix with R rows and (Q/(k×G)) columns and reading out the constellation blocks column by column from the matrix, where R is k×(N/M), and k is a positive integer, the reception method comprising the steps of:
receiving, using a reception unit, a plurality of constellation blocks that have undergone a constellation block permutation on a transmission side, the constellation blocks each consisting of G×M bits;
applying, using a constellation block deinterleaver, an inverse constellation block permutation to the received constellation blocks;
transforming, using a transformer, the constellation blocks, which have undergone the inverse constellation block permutation, into bits of a codeword that have undergone a bit permutation on the transmission side; and
applying, using a bit deinterleaver, an inverse bit permutation to the bits of the codeword, wherein
the inverse constellation block permutation is restoration of an order of the constellation blocks that have been permuted in the constellation block permutation, and
the inverse bit permutation is restoration of an order of the bits of the codeword that have been permuted in the bit permutation.
5. A transmitter for transmitting a codeword generated based on a quasi-cyclic low-density parity-check coding scheme including a repeat-accumulate quasi-cyclic low-density parity-check coding scheme, the codeword consisting of N quasi-cyclic blocks, the quasi-cyclic blocks each consisting of Q bits, the transmitter comprising:
a bit interleaver applying a bit permutation to the bits of the codeword;
a generator generating a plurality of constellation blocks from the permuted bits of the codeword, each of the plurality of constellation blocks being generated from G×M bits;
a constellation block interleaver applying a constellation block permutation to the constellation blocks; and
a transmission unit transmitting the permuted constellation blocks,
wherein the codeword is divided into N/M sections each consisting of M quasi-cyclic blocks,
the constellation blocks are each associated with one of the sections,
the bit permutation is adapted such that the constellation blocks each consist of G×M bits from M different quasi-cyclic blocks of the associated section, and
the constellation block permutation is equivalent to writing the constellation blocks row by row into a matrix with R rows and (Q/(k×G)) columns and reading out the constellation blocks column by column from the matrix, where R is k×(N/M), and k is a positive integer.
6. The transmitter according to claim 5 , wherein
the bit interleaver includes
a section interleaver applying a section permutation to the sections independently of each other so as to permute the bits of each of the sections.
7. The transmitter according to claim 6 , wherein
the section permutation is equivalent to writing the M×Q bits of each of the sections row by row into a matrix with M rows and Q columns and reading out the bits column by column from the matrix.
8. A receiver for receiving a codeword generated based on a quasi-cyclic low-density parity-check coding scheme including a repeat-accumulate quasi-cyclic low-density parity-check coding scheme, the codeword consisting of N quasi-cyclic blocks, the quasi-cyclic blocks each consisting of Q bits, the codeword undergoing predetermined processing and then being transmitted in a transmitter, the predetermined processing including:
a bit permutation of permuting the bits of the codeword;
a generation of generating a plurality of constellation blocks from the permuted bits of the codeword, each of the plurality of constellation blocks being generated from G×M bits; and
a constellation block permutation of permuting the constellation blocks,
wherein the codeword is divided into N/M sections each consisting of M quasi-cyclic blocks,
the constellation blocks are each associated with one of the sections,
the bit permutation is adapted such that the constellation blocks each consisted of G×M bits from M different quasi-cyclic blocks of the associated section, and
the constellation block permutation is equivalent to writing the constellation blocks row by row into a matrix with R rows and (Q/(k×G)) columns and reading out the constellation blocks column by column from the matrix, where R is k×(N/M), and k is a positive integer,
the receiver comprising:
a reception unit receiving a plurality of constellation blocks that have undergone a constellation block permutation on a transmission side, the constellation blocks each consisting of G×M bits;
a constellation block deinterleaver applying an inverse constellation block permutation to the received constellation blocks;
a transformer transforming the constellation blocks, which have undergone the inverse constellation block permutation, into bits of a codeword that have undergone a bit permutation on the transmission side; and
a bit deinterleaver applying an inverse bit permutation to the bits of the codeword, wherein
the inverse constellation block permutation is restoration of an order of the constellation blocks that have been permuted in the constellation block permutation, and
the inverse bit permutation is restoration of an order of the bits of the codeword that have been permuted in the bit permutation.
9. A transmission method for transmitting digital data, the transmission method comprising the steps of:
encoding, using an encoder, a block of data with a forward error correction code;
generating, using a generator, a plurality of first complex symbols from the encoded block of data, the first complex symbols each consisting of respective real-valued symbols as a real component and an imaginary component;
applying, using a complex symbol interleaver, a complex symbol permutation to the first complex symbols;
applying, using a first symbol interleaver, a first symbol permutation to the real-valued symbols constituting the first complex symbols which have undergone the complex symbol permutation;
dividing, using a transformer, the permuted real-valued symbols, which have undergone the first symbol permutation, into a plurality of D-dimensional vectors each consisting of D real-valued symbols, and transforming each of the D-dimensional vectors into a D-dimensional rotated vector by applying a rotation to the D-dimensional vector, the rotation being multiplication of the D-dimensional vector by an orthogonal matrix that is a matrix for spreading values of elements in each dimension of the D-dimensional vector over at least two dimensions;
applying, using a second symbol interleaver, a second symbol permutation to a plurality of transformed real-valued symbols constituting the D-dimensional rotated vectors, the second symbol permutation being an inverse of the first symbol permutation; and
transmitting, using a transmission unit, a plurality of second complex symbols each consisting of the respective transformed real-valued symbols as a real component and an imaginary component, which have undergone the second symbol permutation.
10. The transmission method according to claim 9 , wherein
the second symbol permutation is adapted such that D transformed real-valued symbols of each of the D-dimensional rotated vectors are each allocated to a different one of the second complex symbols.
11. The transmission method according to claim 9 , wherein
the second symbol permutation is adapted such that D transformed real-valued symbols of each of the D-dimensional rotated vectors are spread as evenly as possible over a block of data of the transformed real-valued symbols.
12. A transmitter for transmitting digital data, the transmitter comprising:
an encoder encoding a block of data with a forward error correction code;
a generator generating a plurality of first complex symbols from the encoded block of data, the first complex symbols each consisting of respective real-valued symbols as a real component and an imaginary component;
a complex symbol interleaver applying a complex symbol permutation to the first complex symbols;
a first symbol interleaver applying a first symbol permutation to the real-valued symbols constituting the first complex symbols which have undergone the complex symbol permutation;
a transformer dividing the permuted real-valued symbols, which have undergone the first symbol permutation, into a plurality of D-dimensional vectors each consisting of D real-valued symbols, and transforming each of the D-dimensional vectors into a D-dimensional rotated vector by applying a rotation to the D-dimensional vector, the rotation being multiplication of the D-dimensional vector by an orthogonal matrix that is a matrix for spreading values of elements in each dimension of the D-dimensional vector over at least two dimensions;
a second symbol interleaver applying a second symbol permutation to a plurality of transformed real-valued symbols constituting the D-dimensional rotated vectors, the second symbol permutation being an inverse of the first symbol permutation; and
a transmission unit transmitting a plurality of second complex symbols each consisting of the respective transformed real-valued symbols as a real component and an imaginary component, which have undergone the second symbol permutation.
13. A reception method for receiving digital data, the reception method comprising the steps of:
receiving, using a reception unit, a plurality of first complex symbols each consisting of respective real-valued symbols as a real component and an imaginary component;
applying, using a first symbol interleaver, a first symbol permutation to the real-valued symbols constituting the first complex symbols;
dividing, using a transformer, the real-valued symbols, which have undergone the first symbol permutation, into a plurality of D-dimensional vectors each consisting of D real-valued symbols, and transforming each of the D-dimensional vectors into a D-dimensional rotated vector by applying a rotation to the D-dimensional vector, the rotation being multiplication of the D-dimensional vector by an orthogonal matrix that is a matrix for spreading values of elements in each dimension of the D-dimensional vector over at least two dimensions;
applying, using a second symbol interleaver, a second symbol permutation to a plurality of transformed real-valued symbols constituting the D-dimensional vectors, the second symbol permutation being an inverse of the first symbol permutation;
applying, using a complex symbol interleaver, a complex symbol permutation to a plurality of second complex symbols each consisting of the transformed real-valued symbols which have undergone the second symbol permutation;
generating, using a generator, an encoded block of data from the second complex symbols which have undergone the complex symbol permutation; and
decoding, using a decoder, the encoded block of data with a forward error correction code.
14. A receiver for receiving digital data, the receiver comprising:
a reception unit receiving a plurality of first complex symbols each consisting of respective real-valued symbols as a real component and an imaginary component;
a first symbol interleaver applying a first symbol permutation to the real-valued symbols constituting the first complex symbols;
a transformer dividing the real-valued symbols, which have undergone the first symbol permutation, into a plurality of D-dimensional vectors each consisting of D real-valued symbols, and transforming each of the D-dimensional vectors into a D-dimensional rotated vector by applying a rotation to the D-dimensional vector, the rotation being multiplication of the D-dimensional vector by an orthogonal matrix that is a matrix for spreading values of elements in each dimension of the D-dimensional vector over at least two dimensions;
a second symbol interleaver applying a second symbol permutation to a plurality of transformed real-valued symbols constituting the D-dimensional vectors, the second symbol permutation being an inverse of the first symbol permutation;
a complex symbol interleaver applying a complex symbol permutation to a plurality of second complex symbols each consisting of the transformed real-valued symbols which have undergone the second symbol permutation;
a generator generating an encoded block of data from the second complex symbols which have undergone the complex symbol permutation; and
a decoder decoding the encoded block of data with a forward error correction code.