Transmission device and method for transmitting data frame

A transmission device, applied to a multiple-input multiple-output (MIMO) wireless local area network (WLAN), wherein the transmission device comprises:

• a processor configured to execute computer-executable instructions stored on a computer-readable medium to facilitate:
• acquiring long training field (LTF) parameters, and acquiring a start position I of allocated subcarriers, wherein the LTF parameters comprise a frequency domain transform parameter and a time domain transform parameter that are required for generating an LTF sequence;
• performing, according to the acquired frequency domain transform parameter and the start position I, a frequency domain transform on an LTF basic sequence to obtain an LTF symbol;
• performing, according to the acquired time domain transform parameter, a time domain transform on the LTF symbol obtained by the frequency domain transform on the LTF basic sequence to obtain the LTF sequence;
• and
• a transmitter configured to cooperatively operate with the processor to facilitate:
• adding the LTF sequence obtained by the time domain transform on the LTF symbol to a first data frame, and
• sending the first data frame to a second device in the MIMO WLAN, to facilitate the second device in the MIMO WLAN determining the LTF basic sequence according to the LTF sequence and performing channel estimation for distinguishing multiple spatial streams in the MIMO WLAN according to the LTF basic sequence,
• wherein the frequency domain transform parameter comprises a subcarrier quantity M for distinguishing spatial streams, a quantity L of elements in the LTF basic sequence, and a subcarrier quantity S, and
• wherein, for performing the frequency domain transform, the processor is further configured to facilitate:
• performing, according to M, spread spectrum processing on each element in the LTF basic sequence to obtain an LTF spread spectrum sequence, wherein the LTF spread spectrum sequence comprises M*L elements;
• mapping, starting from the start position I, each element in the LTF spread spectrum sequence obtained by performing the spread spectrum processing to a corresponding subcarrier to obtain a frequency domain LTF sequence;
• performing an S-point IFFT transform on the frequency domain LTF sequence obtained by mapping the each element in the LTF spread spectrum to obtain an LTF basic symbol;
• and
• combining the LTF basic symbol obtained by the S-point IFFT on the frequency domain LTF sequence with a CP to generate the LTF symbol.

A transmission device, applied to a multiple-input multiple-output (MIMO) wireless local area network (WLAN), wherein the transmission device comprises:

• a processor and non-transitory computer-readable medium including computer-executable instructions that, when executed by the processor, facilitate the transmission device:
• receiving a first data frame that carries a long training field (LTF) sequence and that is sent by a first device in the MIMO WLAN;
• determining an LTF basic sequence according to the LTF sequence, and performing a channel estimation for distinguishing multiple spatial streams in the MIMO WLAN according to the LTF basic sequence,
• performing, before the determining the LTF basic sequence according to the LTF sequence, acquiring LTF parameters, and acquiring a start position I of allocated subcarriers, wherein the LTF parameters comprise a frequency domain transform parameter and a time domain transform parameter that are required for generating the LTF sequence by the first device in the MIMO WLAN;
• performing, according to the time domain transform parameter, a time domain inverse transform on the LTF sequence to obtain an LTF symbol;
• and
• performing, according to the acquired frequency domain transform parameter and the acquired start position I, a frequency domain inverse transform on the LTF symbol to obtain the LTF basic sequence
• wherein the frequency domain transform parameter comprises a subcarrier quantity M for distinguishing spatial streams, a quantity L of elements in the LTF basic sequence, and a subcarrier quantity S;
• and
• wherein, for performing the frequency domain inverse transform, the computer-executable instructions facilitate:
• determining, an LTF basic symbol according to the LTF symbol, wherein the LTF symbol comprises the LTF basic symbol and a cyclic prefix (CP);
• performing an S-point fast Fourier transform (FFT) transform on the LTF basic symbol determined according to the LTF symbol to obtain a frequency domain LTF sequence;
• and
• extracting, starting from the start position I, at intervals of └S/L┘ subcarriers, the LTF basic sequence according to the frequency domain LTF sequence obtained by the S-point FFT, wherein └ ┘ indicates round-down.

A method for transmitting a data frame, applied to a multiple-input multiple-output (MIMO) wireless local area network (WLAN), wherein the method comprises:

• acquiring, by a first device in the MIMO WLAN, long training field (LTF) parameters, and acquiring a start position I of allocated subcarriers, wherein the LTF parameters comprise a frequency domain transform parameter and a time domain transform parameter that are required for generating an LTF sequence;
• performing, according to the frequency domain transform parameter and the start position I, a frequency domain transform on an LTF basic sequence to obtain an LTF symbol;
• performing, according to the time domain transform parameter, a time domain transform on the LTF symbol to obtain the LTF sequence;
• and
• adding the LTF sequence to a first data frame, and sending the first data frame to a second device in the MIMO WLAN, to facilitate the second device in the MIMO WLAN determining the LTF basic sequence according to the LTF sequence and performing channel estimation for distinguishing multiple spatial streams in the MIMO WLAN according to the LTF basic sequence,
• wherein the frequency domain transform parameter comprises a subcarrier quantity M for distinguishing spatial streams, a quantity L of elements in the LTF basic sequence, and a subcarrier quantity S;
• and
• wherein the performing, according to the frequency domain transform parameter and the start position I, a frequency domain transform on an LTF basic sequence to obtain an LTF symbol, comprises:
• mapping, starting from the start position I, at intervals of └S/L┘ subcarriers, each element in the LTF basic sequence to a corresponding subcarrier to obtain a frequency domain LTF sequence, wherein └ ┘ indicates round-down;
• performing an S-point inverse fast Fourier transform (IFFT) transform on the frequency domain LTF sequence to obtain an LTF basic symbol;
• and
• combining the LTF basic symbol with a cyclic prefix (CP) to generate the LTF symbol.

A method for transmitting a data frame, applied to a multiple-input multiple-output (MIMO) wireless local area network (WLAN), wherein the method comprises:

• acquiring, by a first device in the MIMO WLAN, long training field (LTF) parameters, and acquiring a start position I of allocated subcarriers, wherein the LTF parameters comprise a frequency domain transform parameter and a time domain transform parameter that are required for generating an LTF sequence;
• performing, according to the frequency domain transform parameter and the start position I, a frequency domain transform on an LTF basic sequence to obtain an LTF symbol;
• performing, according to the time domain transform parameter, a time domain transform on the LTF symbol to obtain the LTF sequence;
• and
• adding the LTF sequence to a first data frame, and sending the first data frame to a second device in the MIMO WLAN, to facilitate the second device in the MIMO WLAN determining the LTF basic sequence according to the LTF sequence and performing channel estimation for distinguishing multiple spatial streams in the MIMO WLAN according to the LTF basic sequence,
• wherein the frequency domain transform parameter comprises a subcarrier quantity M for distinguishing spatial streams, a quantity L of elements in the LTF basic sequence, and a subcarrier quantity S;
• and
• wherein the performing, according to the frequency domain transform parameter and the start position I, a frequency domain transform on an LTF basic sequence to obtain an LTF symbol, comprises:
• performing, according to M, spread spectrum processing on each element in the LTF basic sequence to obtain an LTF spread spectrum sequence, wherein the LTF spread spectrum sequence comprises M*L elements;
• mapping, starting from the start position I, each element in the LTF spread spectrum sequence to a corresponding subcarrier to obtain a frequency domain LTF sequence;
• performing an S-point IFFT transform on the frequency domain LTF sequence to obtain an LTF basic symbol;
• and
• combining the LTF basic symbol with a CP to generate the LTF symbol.

A method for transmitting a data frame, applied to a multiple-input multiple-output (MIMO) wireless local area network (WLAN), wherein the method comprises:

• receiving, by a second device in the MIMO WLAN, a first data frame that carries a long training field (LTF) sequence and that is sent by a first device in the MIMO WLAN;
• and
• determining an LTF basic sequence according to the LTF sequence, and performing channel estimation for distinguishing multiple spatial streams in the MIMO WLAN according to the LTF basic sequence,
• wherein, before the determining an LTF basic sequence according to the LTF sequence, the method further comprises:
• acquiring LTF parameters, and acquiring a start position I of allocated subcarriers, wherein the LTF parameters comprise a frequency domain transform parameter and a time domain transform parameter that are required for generating the LTF sequence by the first device in the MIMO WLAN;
• wherein the determining an LTF basic sequence according to the LTF sequence comprises:
• performing, according to the time domain transform parameter, a time domain inverse transform on the LTF sequence to obtain an LTF symbol;
• and
• performing, according to the frequency domain transform parameter and the start position I, a frequency domain inverse transform on the LTF symbol to obtain the LTF basic sequence,
• wherein the frequency domain transform parameter comprises a subcarrier quantity M for distinguishing spatial streams, a quantity L of elements in the LTF basic sequence, and a subcarrier quantity S;
• and
• wherein the performing, according to the frequency domain transform parameter and the start position I, a frequency domain inverse transform on the LTF symbol to obtain the LTF basic sequence, comprises:
• determining an LTF basic symbol according to the LTF symbol, wherein the LTF symbol comprises the LTF basic symbol and a cyclic prefix (CP);
• performing an S-point fast Fourier transform (FFT) transform on the LTF basic symbol to obtain a frequency domain LTF sequence;
• and
• extracting, starting from the start position I, at intervals of └S/L┘ subcarriers, the LTF basic sequence according to the frequency domain LTF sequence, wherein └ ┘ indicates round-down.