Modulation method, demodulation method, and communication apparatus

1 . A modulation method applied to an electronic device, the method comprising:

obtaining information bit sequences;

dividing the information bit sequences into G groups, wherein G is a positive integer, G is greater than or equal to 2, and G is less than or equal to r; and r is a modulation order, r is a positive integer, a quantity of modulation bits corresponding to a g th group of information bit sequences is r g , a sum of quantities of modulation bits corresponding to the G groups of information bit sequences is equal to the modulation order, and g is any integer from 1 to G, including 1 and G;

wherein based on a modulation scheme being quadrature amplitude modulation (QAM), a length of an encoded bit sequence is 2M, wherein M is a quantity of modulation symbols corresponding to the information bit sequences, and M is a positive integer;

separately encoding each group of information bit sequences to obtain r encoded bit sequences, including:

performing polar encoding on the g th group of information bit sequences, to obtain an encoded bit subsequence with a length of 2M*r g ;

separately performing interleaving, rate matching, and serial-to-parallel conversion on G groups of encoded bit subsequences to obtain the r encoded bit sequences with a length of 2M;

mapping the r encoded bit sequences into a modulation symbol sequence; and

outputting the modulation symbol sequence.

2 . The method according to claim 1 , wherein in response to g being G, r G =1.

3 . The method according to claim 2 , wherein the G groups of encoded bit subsequences are determined in the following manner:

performing polar encoding on a Y th group of information bit sequences, to determine a Y th group of encoded bit subsequences, wherein Y is any integer from 1 to (G−1), including 1 and (G−1);

determining a position and a value of a shaping bit; and

performing polar encoding on the G th group of information bit sequences based on the position and the value of the shaping bit, to determine a G th group of encoded bit subsequences.

4 . The method according to claim 3 , wherein the shaping bit is determined in the following manner:

mapping (G−1) groups of encoded bit subsequences and a group of preset bit sequences into a symbol sequence, wherein the preset bit sequence is an all-zero bit sequence with a length of 2M; and

determining the value of the shaping bit based on the symbol sequence.

5 . The method according to claim 4 , wherein based on a modulation scheme being an amplitude shift keying (ASK) modulation scheme, the all-zero bit sequence has a length of M.

6 . The method according to claim 5 , wherein for the ASK modulation scheme, a length of any gth group of encoded bit subsequences is M*rg.

7 . The method according to claim 5 , wherein for the ASK modulation scheme, a length of each encoded bit sequence among the r encoded bit sequences is M.

8 . The method according to claim 1 , wherein the mapping the r encoded bit sequences into the modulation symbol sequence comprises:

cyclically performing the following: M times until a modulation symbol sequence comprising M modulation symbols is obtained:

selecting one bit from the r encoded bit sequences and mapping the bit into one first symbol according to a preset mapping rule;

selecting one bit from the r encoded bit sequences and mapping the bit into one second symbol according to the preset mapping rule; and

using the first symbol as a real part of a modulation symbol, and using the second symbol as an imaginary part of the modulation symbol, to obtain the modulation symbol.

9 . The method according to claim 8 , wherein

a rule of mapping a same group of encoded bit sequences into a modulation symbol is a first rule; and

a rule of mapping different groups of encoded bit sequences into a modulation symbol is a second rule.

10 . The method according to claim 9 , wherein the first rule is a Gray mapping criterion.

11 . The method according to claim 9 , wherein the second rule is a natural mapping criterion.

12 . A demodulation method applied to an electronic device, the method comprising:

obtaining M received symbols, wherein a modulation order corresponding to the received symbols is r, r is a positive integer, and M is a positive integer;

processing the M received symbols into G groups of first message sequences, including:

determining a g th group of first message sequences based on decoding results of a 1 st to (g−1) th groups and prior probabilities of the g th to G th groups, wherein the prior probabilities of the g th to G th groups are as follows: based on an X th group being a shaping group, the prior probability conforms to non-uniform distribution; or based on an X th group being a non-shaping group, the prior probability conforms to uniform distribution, and the X th group is any group in the g th to G th groups; and

separately decoding the first message sequences to obtain G groups of information bit sequences, wherein G is a positive integer, G is greater than or equal to 2, and G is less than or equal to r; a quantity of modulation bits corresponding to a g th group of information bit sequences is r g ; a sum of quantities of modulation bits corresponding to the G groups of information bit sequences is equal to the modulation order; and g is any integer from 1 to G, including 1 and G.

13 . The method according to claim 12 , wherein the separately decoding the first message sequences to obtain the G groups of information bit sequences comprises:

performing parallel-to-serial conversion, rate de-matching, and de-interleaving on the first message sequences to obtain G groups of second message sequences, wherein a length of each group of second message sequences is M*r g ; and

separately performing polar decoding on each group of second message sequences to obtain the G groups of information bit sequences.

14 . A communication apparatus, comprising:

at least one processor and at least one memory, wherein

the at least one memory is configured to store a computer program; and

the at least one processor is configured to execute the computer program stored in the memory, to enable the communication apparatus to:

obtain information bit sequences; and

divide the information bit sequences into G groups, wherein G is a positive integer, G is greater than or equal to 2, and G is less than or equal to r; and r is a modulation order, r is a positive integer, a quantity of modulation bits corresponding to a g th group of information bit sequences is r g , a sum of quantities of modulation bits corresponding to the G groups of information bit sequences is equal to the modulation order, and g is any integer from 1 to G, including 1 and G;

wherein based on a modulation scheme being quadrature amplitude modulation (QAM), a length of an encoded bit sequence is 2M, wherein M is a quantity of modulation symbols corresponding to the information bit sequences, and M is a positive integer;

separately encode each group of information bit sequences to obtain r encoded bit sequences, including:

performing polar encoding on the g th group of information bit sequences, to obtain an encoded bit subsequence with a length of 2M*r g ;

separately performing interleaving, rate matching, and serial-to-parallel conversion on G groups of encoded bit subsequences to obtain the r encoded bit sequences with a length of 2M;

map the r encoded bit sequences into a modulation symbol sequence; and

output the modulation symbol sequence.

15 . The apparatus according to claim 14 , wherein when g is G, r G =1.

16 . The apparatus according to claim 15 , wherein the at least one processor is further configured to execute the computer program stored in the memory, to enable the communication apparatus to:

perform polar encoding on a Y th group of information bit sequences, to determine a Y th group of encoded bit subsequences, wherein Y is any integer from 1 to (G−1), including 1 and (G−1);

determine a position and a value of a shaping bit; and

perform polar encoding on the G th group of information bit sequences based on the position and the value of the shaping bit, to determine a G th group of encoded bit subsequences.

17 . The apparatus according to claim 16 , wherein the at least one processor is further configured to execute the computer program stored in the memory, to enable the communication apparatus to:

map (G−1) groups of encoded bit subsequences and a group of preset bit sequences into a symbol sequence, wherein the preset bit sequence is an all-zero bit sequence with a length of 2M; and

determine the value of the shaping bit based on the symbol sequence.

18 . The apparatus according to claim 17 , wherein based on a modulation scheme being an amplitude shift keying (ASK) modulation scheme, the all-zero bit sequence has a length of M.

19 . The apparatus according to claim 18 , wherein for the ASK modulation scheme, a length of any gth group of encoded bit subsequences is M*rg.

20 . The apparatus according to claim 14 , wherein the at least one processor is further configured to execute the computer program stored in the memory, to enable the communication apparatus to:

cyclically perform the following M times until a modulation symbol sequence comprising M modulation symbols is obtained:

selecting one bit from the r encoded bit sequences and mapping the bit into one first symbol according to a preset mapping rule;

selecting one bit from the r encoded bit sequences and mapping the bit into one second symbol according to the preset mapping rule; and

using the first symbol as a real part of a modulation symbol, and using the second symbol as an imaginary part of the modulation symbol, to obtain one of the modulation symbols.