Data retransmission method and communication apparatus
This application provides example data retransmission methods and communication apparatuses. One example method includes receiving a physical protocol data unit (PPDU) by a first device and from a second device, where the PPDU includes a signaling field and a data field, the data field includes retransmitted data and newly transmitted data, the signaling field includes first indication information, or the signaling field comprises the first indication information and second indication information, the first indication information indicates a first modulation and coding scheme (MCS) and a first coding mode that are used for the newly transmitted data, and the second indication information indicates a second MCS and a second coding mode that are used for the retransmitted data. The PPDU is demodulated based on the signaling field.
1. A data retransmission method, comprising:
receiving, by a first device, a physical protocol data unit (PPDU) from a second device, wherein the PPDU comprises a signaling field and a data field, the data field comprises retransmitted data and newly transmitted data, the signaling field comprises (1) first indication information or (2) the first indication information and second indication information, wherein the first indication information is used to indicate a first modulation and coding scheme (MCS) and a first coding mode that are used for the newly transmitted data, and the second indication information is used to indicate a second MCS and a second coding mode that are used for the retransmitted data, and wherein the data field comprises M OFDM symbols in time domain, and a quantity of symbols occupied by the newly transmitted data in the data field is calculated according to the following formula:
M-ceil (L/K), wherein:
L is a total quantity of bits of the retransmitted data, K is a quantity of bits that are used to carry data on each of the M OFDM symbols, ceil ( ) indicates rounding up, and M, L, and K are positive integers; and
demodulating the PPDU based on the signaling field.
2. The method according to claim 1 , wherein the signaling field comprises the first indication information, and the demodulating the PPDU based on the signaling field comprises:
demodulating the newly transmitted data comprised in the data field based on the first indication information by using the first MCS and the first coding mode; and
demodulating the retransmitted data comprised in the data field by using a third MCS and a third coding mode that are used when the retransmitted data is demodulated last time.
3. The method according to claim 1 , wherein the signaling field comprises the first indication information and the second indication information, and the demodulating the PPDU based on the signaling field comprises:
demodulating the newly transmitted data comprised in the data field based on the first indication information and the second indication information by using the first MCS and the first coding mode; and
demodulating the retransmitted data comprised in the data field by using the second MCS and the second coding mode.
4. The method according to claim 3 , wherein that the signaling field comprises the first indication information and the second indication information comprises:
the signaling field comprises an extremely high throughput signal field B (EHT-SIG-B), and the EHT-SIG-B comprises a first signaling field and a second signaling field, wherein the first signaling field comprises the first indication information, and the second signaling field comprises the second indication information.
5. The method according to claim 3 , wherein that the signaling field comprises the first indication information and the second indication information comprises:
the signaling field comprises an extremely high throughput signal field B (EHT-SIG-B) and an extremely high throughput signal field C (EHT-SIG-C), wherein the EHT-SIG-B comprises the first indication information, and the EHT-SIG-C comprises the second indication information.
6. The method according to claim 3 , wherein that the signaling field comprises the first indication information and the second indication information comprises:
the signaling field comprises an extremely high throughput signal field C (EHT-SIG-C), wherein the EHT-SIG-C comprises the first indication information and the second indication information; and
the signaling field further comprises an extremely high throughput signal field B (EHT-SIG-B), wherein the EHT-SIG-B comprises an MCS field, and a reserved value of the MCS field is used to indicate that the data field comprises the retransmitted data.
7. The method according to claim 6 , wherein the MCS field further comprises a plurality of non-reserved values, and each non-reserved value is used to indicate the first MCS and the first coding mode that are used for the newly transmitted data.
8. A communication apparatus, comprising:
at least one processor;
a non-transitory computer readable medium storing instructions that, when executed by the at least one processor, cause the communication apparatus to perform operations comprising:
receiving a physical protocol data unit (PPDU) from a first device, wherein the PPDU comprises a signaling field and a data field, the data field comprises retransmitted data and newly transmitted data, the signaling field comprises (1) first indication information or (2) the first indication information and second indication information, wherein the first indication information indicates a first modulation and coding scheme (MCS) and a first coding mode that are used for the newly transmitted data, and the second indication information indicates a second MCS and a second coding mode that are used for the retransmitted data, and wherein the data field comprises M OFDM symbols in time domain, and a quantity of symbols occupied by the newly transmitted data in the data field is calculated according to the following formula:
M-ceil (L/K), wherein:
L is a total quantity of bits of the retransmitted data, K is a quantity of bits that are used to carry data on each of the M OFDM symbols, ceil ( ) indicates rounding up, and M, L, and K are positive integers; and
demodulating the PPDU based on the signaling field.
9. The communication apparatus according to claim 8 , wherein the signaling field comprises the first indication information, and the demodulating the PPDU based on the signaling field comprises:
demodulating the newly transmitted data comprised in the data field based on the first indication information by using the first MCS and the first coding mode; and
demodulating the retransmitted data comprised in the data field by using a third MCS and a third coding mode that are used when the retransmitted data is demodulated last time.
10. The communication apparatus according to claim 8 , wherein the signaling field comprises the first indication information and the second indication information, and the demodulating the PPDU based on the signaling field comprises:
demodulating the newly transmitted data comprised in the data field based on the first indication information and the second indication information by using the first MCS and the first coding mode; and
demodulating the retransmitted data comprised in the data field by using the second MCS and the second coding mode.
11. The communication apparatus according to claim 10 , wherein that the signaling field comprises the first indication information and the second indication information comprises:
the signaling field comprises an extremely high throughput signal field B (EHT-SIG-B), and the EHT-SIG-B comprises a first signaling field and a second signaling field, wherein the first signaling field comprises the first indication information, and the second signaling field comprises the second indication information.