Method and apparatus for supporting low bit rate coding, and computer storage medium
The disclosure discloses a method for supporting low bit rate coding. A source data packet to be coded is repeated for i times, and the data packet which is repeated for i times is coded. The disclosure also discloses an apparatus for supporting low bit rate coding and a computer storage medium.
1. An apparatus for supporting low bit rate coding, comprising: a repeater and an encoder, wherein
the repeater is configured to repeat a source data packet for i times,
wherein repeating the source data packet for i times comprises: splitting the source data packet into j sub-data packets with a same length, and repeating each of the j sub-data packets for i times respectively to obtain a repeated data packet, i and j being positive integers; and
the encoder is configured to encode the repeated data packet, the encoding being Low Density Parity Check (LDPC) coding,
wherein encoding the repeated data packet comprises: encoding the repeated data packet based on a basic parity check matrix and an expansion factor to obtain a master code data packet.
2. The apparatus according to claim 1 , wherein the encoder is further configured to read, before the encoding, the basic parity check matrix; and
the encoder is further configured to set, after reading the basic parity check matrix, values of r non −1 elements in the basic parity check matrix as −1, where r is an integer which is greater than or equal to 0 and is smaller than r0, r0 is a number of original non −1 elements in the basic parity check matrix, the −1 element represents a z×z zero matrix, and the non −1 element represents a z×z shifted unit matrix.
3. The apparatus according to claim 1 , wherein the length of each of the j sub-data packets is equal to the expansion factor.
4. A method for supporting low bit rate coding, comprising:
repeating a source data packet for i times,
wherein repeating the source data packet for i times comprises: splitting the source data packet into j sub-data packets with a same length, and repeating each of the j sub-data packets for i times respectively to obtain a repeated data packet, i and j being positive integers; and
encoding the repeated data packet, wherein the encoding is Low Density Parity Check (LDPC) coding,
wherein encoding the repeated data packet comprises: encoding the repeated data packet based on a basic parity check matrix and an expansion factor to obtain a master code data packet.
5. The method according to claim 4 , further comprising: carrying out rate matching on the master code data packet so as to obtain an N-bit coded data packet, N being a code length.
6. The method according to claim 4 , wherein the basic parity check matrix is as follows:
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
A
B
0
−1
0
−1
0
−1
0
−1
0
0
−1
−1
−1
−1
−1
−1
−1
1
0
−1
−1
34
−1
12
−1
36
18
0
−1
−1
−1
−1
−1
−1
2
8
−1
0
−1
0
−1
0
−1
−1
13
0
−1
−1
−1
−1
−1
3
−1
16
40
−1
32
−1
22
−1
−1
−1
19
0
−1
−1
−1
−1
4
−1
20
−1
22
−1
2
−1
28
32
−1
−1
21
0
−1
−1
−1
5
30
−1
18
−1
−1
14
−1
30
−1
37
−1
−1
31
0
−1
−1
6
40
−1
12
−1
38
−1
6
−1
−1
−1
26
−1
−1
13
0
−1
7
−1
24
−1
20
10
−1
2
−1
−1
−1
−1
18
−1
−1
5
0
wherein the leftmost column represents row indexes, the uppermost row represents column indexes, a letter ‘A’ represents a system bit part matrix, and a letter ‘B’ represents a check bit part matrix.
7. The method according to claim 4 , further comprising: filling, before repeating the source data packet for i times, the source data packet with q1 elements to expand the source data packet into a first data packet, q1 being a positive integer.
8. The method according to claim 7 , further comprising: filling, after repeating the source data packet for i times and before encoding the repeated data packet, the repeated data packet with q2 elements to obtain a second data packet, q2 being a positive integer.
9. The method according to claim 8 , further comprising: encoding the second data packets to obtain a check data packet.
10. The method according to claim 9 , wherein the basic parity check matrix is as follows:
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
A
B
0
−1
0
−1
0
−1
0
−1
0
0
−1
−1
−1
−1
−1
−1
−1
1
0
−1
−1
34
−1
12
−1
36
18
0
−1
−1
−1
−1
−1
−1
2
8
−1
0
−1
0
−1
0
−1
−1
13
0
−1
−1
−1
−1
−1
3
−1
16
40
−1
32
−1
22
−1
−1
−1
19
0
−1
−1
−1
−1
4
−1
20
−1
22
−1
2
−1
28
32
−1
−1
21
0
−1
−1
−1
5
30
−1
18
−1
−1
14
−1
30
−1
37
−1
−1
31
0
−1
−1
6
40
−1
12
−1
38
−1
6
−1
−1
−1
26
−1
−1
13
0
−1
7
−1
24
−1
20
10
−1
2
−1
−1
−1
−1
18
−1
−1
5
0
wherein the leftmost column represents row indexes, the uppermost row represents column indexes, a letter ‘A’ represents a system bit part matrix, and a letter ‘B’ represents a check bit part matrix.
11. The method according to claim 10 , further comprising: combining the check data packet and the source data packet into the master code data packet.
12. The method according to claim 11 , further comprising: carrying out rate matching on the master code data packet so as to obtain an N-bit coded data packet, N being a code length.
13. The method according to claim 12 , wherein the encoding is (16×42, 8×42) LDPC coding, the basic parity check matrix is an 8×16 matrix, the expansion factor z=42, the source data packet is a signalling sequence a=[a 0 , a 1 , a 2 , . . . , a 79 ] (k=80 bits), and when LDPC coding is carried out on the signalling sequence a using a 1/2 bit rate LDPC code basic parity check matrix to obtain a coded data packet e (n=672 bits),
d i =a i-172 i= 172,173, . . . , 209
d i =a i-214 i= 214,215, . . . , 293
d i =a i-256 i= 294,295, . . . , 335;
d i =0 i =others
e j =s j j= 0,1, . . . , 415
e j =s j-416 j= 416,417, . . . , 671;
firstly, the signalling sequence a is filled with 4 bit elements to expand into a first data packet with a length of 84-bit, the first data packet is split into two 42-bit sub-data packets, and then each 42-bit sub-data packet is repeated for one time respectively;
then, the repeated data packet is filled with 168 bit elements and expanded to obtain a second data packet with a length of 336-bit, d=[d 0 , d 1 , . . . , d 335 ], d being as follows:
d i =a i-172 i= 172,173, . . . , 209
d i =a i-214 i= 214,215, . . . , 293
d i =a i-256 i= 294,295, . . . , 335;
d i =0 i =others
then, LDPC coding is carried out on the second data packet d to obtain a check data packet with a length of 336-bit, b=[b 0 , b 1 , . . . , b 335 ], and the signalling sequence a and the check data packet b are combined into a master code data packet with a length of 416-bit,
s =[ a,b ]=[ s 0 ,s 1 , . . . , s 415 ]; and
finally, a 672-bit coded data packet e is constructed by the master code data packet s, e being:
e j =s j =0,1, . . . , 415
e j =s j-416 j= 416,417, . . . , 671.
14. The method according to claim 4 , wherein the method further comprises: reading, before the coding, the basic parity check matrix; and the coding comprises: setting values of r non −1 elements in the basic parity check matrix as −1, where r is an integer which is greater than or equal to 0 and is smaller than r0, r0 is a number of original non −1 elements in the basic parity check matrix, the −1 element represents a z×z zero matrix, and the non −1 element represents a z×z shifted unit matrix.
15. The method according to claim 4 , wherein the length of each of the j sub-data packets is equal to the expansion factor.
16. A computer storage medium, wherein a computer program is stored therein and is configured to execute a method for supporting low bit rate coding, the method comprises the following steps of:
repeating a source data packet for i times,
wherein repeating the source data packet for i times comprises: splitting the source data packet into j sub-data packets with a same length, and repeating each of the j sub-data packets for i times respectively to obtain a repeated data packet, i and j being positive integers; and
encoding the repeated data packet, wherein the encoding is Low Density Parity Check (LDPC) coding,
wherein encoding the repeated data packet comprises: encoding the repeated data packet based on a basic parity check matrix and an expansion factor to obtain a master code data packet.