Encoding method and device, decoding method and device, and storage medium

1. An encoding method comprising:

encoding an initial bit sequence to be encoded with a low density parity check code LDPC having a code rate R 1 , to obtain a first bit sequence, where 0≤R 1 ≤1;

dividing the first bit sequence into t bit sequence segments, wherein a relationship exists between the number t of the bit sequence segments and the code rate R 1 :

t

=

[

[

j

R

1

]

]

,

where t is a positive integer greater than or equal to 1, j is a positive integer, and the operator represents a rounding operation;

linearly combining at least two bit sequence segments in the first bit sequence to obtain a second bit sequence, wherein linearly combining at least two bit sequence segments in the first bit sequence to obtain a second bit sequence comprises: a selecting step of selecting t 1 bit sequence segments from t bit sequence segments; a combining step of linearly combining bits at corresponding positions in the t 1 bit sequence segments to obtain a bit sequence segment D 1 , where 1<t 1 ≤t; repeating the selecting step and the combining step to generate w bit sequence segments {D 1 , D 2 , . . . , D w }, where w is a positive integer; and cascading the w bit sequence segments to obtain the second bit sequence; and

cascading the first bit sequence and the second bit sequence to obtain a target bit sequence having a code rate R 2 , where 0≤R 2 ≤R 1 ≤1.

2. The method according to claim 1 , wherein linearly combining bits at corresponding positions in the t 1 bit sequence segments comprises at least one of:

performing binary addition of bits at corresponding positions in the t 1 bit sequence segments; and

first performing interleaving on at least two bit sequence segments of the t 1 bit sequence segments, and then performing binary addition of bits at corresponding positions in the t 1 bit sequence segments.

3. The method according to claim 1 , wherein selecting t 1 bit sequence segments from t bit sequence segments comprises at least one of:

performing selection according to a pre-determined rule between an encoding end and a decoding end;

performing selection according to an indication in a signal sent from the encoding end to the decoding end; and

performing selection according to an indication in a signal sent from the decoding end to the encoding end.

4. The method according to claim 1 , wherein the number w of bit sequence segments is determined according to t, R 1 , and R 2 .

5. The method according to claim 4 , wherein the number w of bit sequence segments of the second bit sequence is determined according to a formula of:

w

=

[

[

t

·

(

R

1

R

2

-

1

)

]

]

,

where, the operator represents a rounding operation.

6. The method according to claim 1 , wherein a bit length L 2 of the second bit sequence is determined according to L 1 , R 1 , and R 2 , wherein L 1 is a bit length of the first bit sequence.

7. The method according to claim 6 , wherein the bit length L 2 of the second bit sequence is determined according to a formula of

L

2

=

[

[

L

1

·

(

R

1

R

2

-

1

)

]

]

,

where, the operator represents a rounding operation.

8. The method according to claim 1 , wherein when R 1 =1/3, R 2 =1/5, and the first bit sequence comprises 3 bit sequence segments {P 1 , P 2 , P 3 }, the method further comprises:

linearly combining the bit sequence segments P 1 and P 2 , and linearly combining the bit sequence segments P 1 and P 3 to obtain a second bit sequence; and

cascading the first bit sequence and the second bit sequence to obtain a target bit sequence having a code rate R 2 =1/5.

9. A decoding method comprising:

decoding a target bit sequence having a code rate R 2 with a low density parity check code LDPC having a code rate R 1 , to obtain an initial bit sequence to be encoded, where 0≤R 2 ≤R 1 ≤1, wherein the target bit sequence is formed by cascading a first bit sequence and a second bit sequence, the first bit sequence is obtained by encoding an initial bit sequence to be encoded with a LDPC having a code rate R 1 , and the second bit sequence is obtained by dividing the first bit sequence into t bit sequence segments and linearly combining at least two bit sequence segments in the first bit sequence, wherein a relationship exists between the number t of the bit sequence segments and the code rate R 1 :

t

=

[

[

j

R

1

]

]

,

wherein t is a positive integer greater than or equal to 1, j is a positive integer, and the operator represents a rounding operation; and linearly combining at least two bit sequence segments in the first bit sequence comprises: a selecting step of selecting t 1 bit sequence segments from t bit sequence segments; a combining step of linearly combining bits at corresponding positions in the t 1 bit sequence segments to obtain a bit sequence segment D 1 , where 1<t 1 ≤t; repeating the selecting step and the combining step to generate w bit sequence segments {D 1 , D 2 , . . . , D w }, where w is a positive integer; and cascading the w bit sequence segments to obtain the second bit sequence.

10. An encoding device, comprising:

a processor;

a memory for storing instructions executable by the processor;

wherein the processor is configured to:

encode an initial bit sequence to be encoded with a low density parity check code LDPC having a code rate R 1 , to obtain a first bit sequence, where 0≤R 1 ≤1;

divide the first bit sequence into t bit sequence segments, wherein a relationship exists between the number t of the bit sequence segments and the code rate R 1 :

t

=

[

[

j

R

1

]

]

,

where t is a positive integer greater than or equal to 1, j is a positive integer, and the operator represents a rounding operation;

linearly combine at least two bit sequence segments in the first bit sequence to obtain a second bit sequence, wherein the processor is further configured to: select t 1 bit sequence segments from t bit sequence segments of the first bit sequence; linearly combine bits at corresponding positions in the t 1 bit sequence segments to obtain a bit sequence segment D 1 , where 1<t 1 ≤t; and cascade w bit sequence segments {D 1 , D 2 , . . . , D w } generated by the selection unit and the combining unit to obtain the second bit sequence, where w is a positive integer; and

cascade the first bit sequence and the second bit sequence to obtain a target bit sequence having a code rate R 2 , where 0≤R 2 ≤R 1 ≤1.

11. The device according to claim 10 , wherein the processor is further configured to perform at least one of:

performing binary addition of the bits at corresponding positions in the t 1 bit sequence segments; and

first performing interleaving on at least two bit sequence segments of the t 1 bit sequence segments, and then performing binary addition of the bits at corresponding positions in the t 1 bit sequence segments.

12. The device according to claim 10 , wherein the processor is further configured to:

according to a pre-determined rule between an encoding end and a decoding end, select t 1 bit sequence segments from t bit sequence segments;

according to an indication in a signal sent from the encoding end to the decoding end, select t 1 bit sequence segments from t bit sequence segments; and

according to an indication in a signal sent from the decoding end to the encoding end, select t 1 bit sequence segments from t bit sequence segments.

13. The device according to claim 10 , wherein the number w of bit sequence segments of the second bit sequence is determined according to t, R 1 , and R 2 .

14. The device according to claim 13 , wherein the number w of bit sequence segments of the second bit sequence is determined according to a formula of:

w

=

[

[

t

·

(

R

1

R

2

-

1

)

]

]

,

where, the operator represents a rounding operation.

15. The device according to claim 10 , wherein a bit length L 2 of the second bit sequence is determined according to L 1 , R 1 , and R 2 , wherein L 1 is a bit length of the first bit sequence.

16. The device according to claim 15 , wherein the bit length L 2 of the second bit sequence is determined according to a formula of:

L

2

=

[

[

L

1

·

(

R

1

R

2

-

1

)

]

]

,

where, the operator represents a rounding operation.