Physical layer protocol data unit transmission method and apparatus
Embodiments of the present disclosure provide a physical layer protocol data unit (PPDU) transmission method and a corresponding PPDU transmission apparatus. Application of the method and apparatus in the embodiments of the present disclosure enables a receive end to quickly determine the starting position of the feature signal sequence by means of blind detection, and ensures that the receive end quickly completes data processing and status switching.
1. An apparatus for physical layer protocol data unit (PPDU) transmission, the apparatus being a first apparatus in a wireless local area network and comprising:
a processor, and
a memory coupled to the processor, wherein the memory stores instructions that, when executed by the processor, cause the first apparatus to:
generate a PPDU, wherein:
the PPDU comprises: a legacy signaling (L-SIG) field, indication information, and a signal extension (SE) field;
the SE field is located behind a last orthogonal frequency division multiplexing (OFDM) symbol that carries data information in the PPDU;
the L-SIG field comprises a Length field indicating a length;
a value of the indication information is set based on a length of the SE field;
a first value of the indication information indicates a second apparatus to keep a value of M1 unchanged, wherein M1 is a quantity of OFDM symbols calculated according to the length indicated by the Length field; and
a second value of the indication information indicates the second apparatus to subtract 1 from the value of M1; and
send the PPDU to the second apparatus.
2. The apparatus according to claim 1 , wherein the indication information is further set based on the length indicated by the Length field.
3. The apparatus according to claim 1 , wherein the length of the SE field is one of: 4 microseconds (μs), 8 μs, 12 μs, and 16 μs.
4. The apparatus according to claim 1 , wherein the PPDU further comprises a high efficiency signaling (HE-SIG) field, and the HE-SIG field includes the indication information.
5. The apparatus according to claim 1 , wherein the PPDU further comprises a data field, and the quantity M1 is a quantity of calculated OFDM symbols in the data field.
6. The apparatus according to claim 3 , wherein the length of the SE field corresponds to a position in which coding is stopped in the last OFDM symbol.
7. The apparatus according to claim 6 , wherein the length of the SE field has four values 4 μs, 8 μs, 12 μs, and 16 μs, respectively corresponding to positions ¼, ½, ¾, and 1 in which coding is stopped in the last OFDM symbol in the PPDU.
8. An apparatus for physical layer protocol data unit (PPDU) transmission, the apparatus being a second apparatus in a wireless local area network and comprising:
a processor, and
a memory coupled to the processor, wherein the memory stores instructions that, when executed by the processor, cause the second apparatus to:
receive a PPDU from a first apparatus, wherein:
the PPDU comprises: a legacy signaling (L-SIG) field, indication information, and a signal extension (SE) field;
the SE field is located behind a last orthogonal frequency division multiplexing (OFDM) symbol that carries data information in the PPDU;
a value of the indication information is set based on a length of the SE field;
the L-SIG field comprises a Length field indicating a length;
a first value of the indication information indicates the second apparatus to keep a value of M1 unchanged, wherein M1 is a quantity of OFDM symbols calculated according to the length indicated by the Length field; and
a second value of the indication information indicates the second apparatus to subtract 1 from the value of M1; and
determine that a quantity of OFDM symbols for the second apparatus is equal to the value of M1 in response to a value of the indication information being the first value; and
determine that a quantity of OFDM symbols for the second apparatus is equal to (M1-1) in response to a value of the indication information being the second value.
9. The apparatus according to claim 8 , wherein the PPDU further comprises a high efficiency signaling (HE-SIG) field, and the HE-SIG field includes the indication information.
10. The apparatus according to claim 8 , wherein the PPDU further comprises a data field, and the quantity M1 is a quantity of calculated OFDM symbols in the data field.
11. The apparatus according to claim 8 , wherein the length of the SE field is one of: 4 microseconds (μs), 8 μs, 12 μs, and 16 μs.
12. The apparatus according to claim 11 , wherein the length of the SE field corresponds to a position in which coding is stopped in the last OFDM symbol in the PPDU.
13. The apparatus according to claim 12 , wherein the length of the SE field has four values 4 μs, 8 μs, 12 μs, and 16 μs, respectively corresponding to positions ¼, ½, ¾, and 1 in which coding is stopped in the last OFDM symbol in the PPDU.
14. A method for transmitting a physical layer protocol data unit (PPDU), wherein the method is applied in a wireless local area network, the method comprising:
generating, by a first apparatus, a PPDU, wherein:
the PPDU comprises: a legacy signaling (L-SIG) field, indication information, and a signal extension (SE) field;
the SE field is located behind a last orthogonal frequency division multiplexing (OFDM) symbol that carries data information in the PPDU;
a value of the indication information is set based on a length of the SE field;
the L-SIG field comprises a Length field indicating a length;
a first value of the indication information indicates a second apparatus to keep a value of M1 unchanged, wherein M1 is a quantity of OFDM symbols calculated according to the length indicated by the Length field; and
a second value of the indication information indicates the second apparatus to subtract 1 from the value of M1; and
sending, by the first apparatus, the PPDU to the second apparatus.
15. The method according to claim 14 , wherein the PPDU further comprises a high efficiency signaling (HE-SIG) field, and the HE-SIG field includes the indication information.
16. The method according to claim 14 , wherein the PPDU further comprises a data field, and the quantity M1 is a quantity of calculated OFDM symbols in the data field.
17. The method according to claim 14 , wherein the length of the SE field is one of: 4 microseconds (μs), 8 μs, 12 μs, and 16 μs.
18. The method according to claim 17 , wherein the length of the SE field corresponds to a position in which coding is stopped in the last OFDM symbol in the PPDU.
19. The method according to claim 18 , wherein the length of the SE field has four values 4 μs, 8 μs, 12 μs, and 16 μs, respectively corresponding to positions ¼, ½, ¾, and 1 in which coding is stopped in the last OFDM symbol in the PPDU.
20. The method according to claim 14 , wherein the indication information is further set based on the length indicated by the Length field.