Communication method for wireless fidelity Wi-Fi system and apparatus
In the field of communication technologies, a communication method for a wireless fidelity (Wi-Fi) system and an apparatus provide improved performance of demodulating a Wi-Fi frame by the apparatus. The communication method for the wireless fidelity (Wi-Fi) system includes: generating a Wi-Fi frame including a first preamble field, where the first preamble field indicates a modulation and coding scheme MCS of at least one symbol in a data field in the Wi-Fi frame, an MCS order of first m symbols in the at least one symbol is less than an MCS order of another symbol, and m is a positive integer greater than or equal to 1; and transmitting the Wi-Fi frame.
1 . A communication method for a wireless fidelity (Wi-Fi) system, the communication method comprising:
generating a Wi-Fi frame comprising a preamble field and a data field including a plurality of orthogonal frequency division multiplexing (OFDM) symbols, wherein the preamble field indicates a modulation and coding scheme (MCS) of at least one symbol of the plurality of OFDM symbols in the data field in the Wi-Fi frame, a MCS order of first m symbol(s) at a beginning of the data field including the plurality of OFDM symbols is less than a MCS order of another symbol in the data field including the plurality of OFDM symbols after the first m symbol(s), and m is a positive integer greater than or equal to 1; and
transmitting the Wi-Fi frame.
2 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 1 , wherein the preamble field comprises a high efficient-signal field A (HE-SIGA); and the method further comprises:
determining a value by which the MCS order of the first m symbol(s) is lower than the MCS order of the another symbol; and
including the value and the MCS order of the another symbol in the high efficient-signal field A (HE-SIGA).
3 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 1 , wherein the preamble field comprises a high efficient-signal field A (HE-SIGA); and the method further comprises:
including a MCS order of the at least one symbol in the high efficient-signal field A (HE-SIGA).
4 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 1 , wherein the preamble field comprises a high efficient-signal field A (HE-SIGA); and the method further comprises:
including the MCS order of the another symbol in the high efficient-signal field A (HE-SIGA).
5 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 1 , and wherein the preamble field comprises a high efficient-signal field A (HE-SIGA); and the method further comprises:
including, in the high efficient-signal field A (HE-SIGA), a bit for indicating a value of m.
6 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 1 , wherein the preamble field comprises a high efficient-signal field A (HE-SIGA); the high efficient-signal field A (HE-SIGA) comprises a quantity of spatial streams of user data; and m=k*Nss, Nss is the quantity of the spatial streams, and k is a positive integer greater than or equal to 1.
7 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 6 , wherein each of the first m symbol(s) carries one spatial stream of the user data.
8 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 1 , wherein the preamble field further comprises a high efficient-long training field (HE-LTF); and m=S, and S is a quantity of symbol(s) of the HE-LTF.
9 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 8 , wherein
each of the first m symbol(s) carries a plurality of spatial streams of user data; a plurality of spatial streams of user data carried in the at least one symbol are weighted by using an orthogonal P matrix, and the orthogonal P matrix is an m*m orthogonal matrix.
10 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 1 , wherein a subcarrier spacing of the first m symbol(s) is greater than a subcarrier spacing of the another symbol.
11 . A communication method for a wireless fidelity (Wi-Fi) system, the communication method comprising:
receiving a Wi-Fi frame transmitted by a communication apparatus, the Wi-Fi frame including a preamble field and a data field including a plurality of orthogonal frequency division multiplexing (OFDM) symbols;
determining, based on the preamble field in the Wi-Fi frame, a modulation and coding scheme (MCS) of at least one symbol of the plurality of OFDM symbols in the data field in the Wi-Fi frame transmitted by the communication apparatus, wherein a MCS order of first m symbol(s) at a beginning of the data field including the plurality of OFDM symbols is less than a MCS order of another symbol in the data field including the plurality of symbols after the first m symbol(s), and m is a positive integer greater than or equal to 1; and
demodulating the at least one symbol based on the MCS.
12 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 11 , wherein the preamble field comprises a high efficient-signal field A (HE-SIGA); and
the high efficient-signal field A (HE-SIGA) comprises the MCS order of the another symbol and a value for indicating that the MCS order of the first m symbol(s) is lower than the MCS order of the another symbol.
13 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 11 , wherein the preamble field comprises a high efficient-signal field A (HE-SIGA); and
the high efficient-signal field A (HE-SIGA) comprises a MCS order of the at least one symbol.
14 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 11 , wherein the preamble field comprises a high efficient-signal field A (HE-SIGA); and the high efficient-signal field A (HE-SIGA) comprises the MCS order of the another symbol; and
the determining, based on the preamble field in the Wi-Fi frame, the modulation and coding scheme (MCS) of at least one symbol in the data field in the Wi-Fi frame transmitted by the communication apparatus comprises:
determining the MCS order of the another symbol based on the high efficient-signal field A (HE-SIGA); and
determining the MCS order of the first m symbol(s) based on the MCS order of the another symbol.
15 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 11 , wherein the preamble field comprises a high efficient-signal field A (HE-SIGA); and the high efficient-signal field A (HE-SIGA) comprises a bit for indicating a value of m.
16 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 11 , wherein the preamble field comprises a high efficient-signal field A (HE-SIGA); the high efficient-signal field A (HE-SIGA) comprises a quantity of spatial streams of user data; and m=k*Nss, Nss is the quantity of the spatial streams, and k is a positive integer greater than or equal to 1.
17 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 16 , wherein
each of the first m symbol(s) carries one spatial stream of the user data.
18 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 11 , wherein the preamble field comprises a high efficient-long training field (HE-LTF); and m=S, and S is a quantity of symbol(s) of the HE-LTF.
19 . The communication method for the wireless fidelity (Wi-Fi) system according to claim 18 , wherein
each of the first m symbol(s) carries a plurality of spatial streams of user data; a plurality of spatial streams of user data carried in the at least one symbol are weighted by using an orthogonal P matrix, and the orthogonal P matrix is an m*m orthogonal matrix.
20 . A communication apparatus comprising:
a processor, configured to generate a (Wi-Fi) frame comprising a preamble field and a data field including a plurality of orthogonal frequency division multiplexing (OFDM) symbols, wherein the preamble field indicates a modulation and coding scheme (MCS) of at least one symbol of the plurality of OFDM symbols in the data field in the Wi-Fi frame, a MCS order of first m symbol(s) at a beginning of the data field including the plurality of OFDM symbols is less than a MCS order of another symbol in the data field including the plurality of OFDM symbols after the first m symbol(s), and m is a positive integer greater than or equal to 1; and
a transmitter, configured to transmit the Wi-Fi frame.