Method and apparatus for transmitting PLCP frame in wireless local area network system

1. An apparatus, comprising:

at least one processor;

at least one memory including computer program code, the memory and the computer program code configured to, working with the processor, cause the apparatus to perform at least the following:

receive a data frame, the data frame comprising:

a legacy signal field including a first symbol that is mapped onto a first binary phase shift keying (BPSK) constellation;

a Very High Throughput Signal (VHT-SIG) field including a second symbol and a third symbol, the second symbol being mapped onto the first BPSK constellation, and the third symbol being mapped onto a second BPSK constellation, and the second BSPK constellation being rotated by 90° counter-clockwise relative to the first BPSK constellation; and

wherein the second symbol includes an indicator indicating Single User-Multiple Input Multiple Output (SU-MIMO) transmission or multi user-MIMO (MU-MIMO) transmission, and the third symbol includes a cyclic redundancy check (CRC) for the second symbol and, at least a portion of, the third symbol.

2. The apparatus of claim 1 , further comprising a wireless local area network transceiver, wherein the data frame is received by the wireless local area network transceiver.

3. The apparatus of claim 2 , further comprising at least one antenna, wherein the wireless local area network transceiver receives the data frame by way of the at least one antenna.

4. The apparatus of claim 1 , wherein the third symbol is immediately after the second symbol.

5. The apparatus of claim 1 , wherein the data frame is a Physical Layer Convergence Procedure Protocol Data Unit (PPDU).

6. The apparatus of claim 4 , wherein the PPDU omits a high throughput signal (HT_SIG) field between the legacy field and the VHT-SIG field.

7. The apparatus of claim 1 , wherein the VHT-SIG field further includes a multiplexing number indicating a number of spatial streams.

8. The apparatus of claim 7 , wherein the second symbol includes the multiplexing number indicating the number of spatial streams.

9. The apparatus of claim 1 , wherein the VHT-SIG field is immediately after the legacy field.

10. The apparatus of claim 1 , wherein the second symbol is immediately after the first symbol.

11. A method comprising:

receiving a data frame, the data frame comprising:

a legacy signal field including a first symbol that is mapped onto a first binary phase shift keying (BPSK) constellation;

a Very High Throughput Signal (VHT-SIG) field including a second symbol and a third symbol, the second symbol being mapped onto the first BPSK constellation, and the third symbol being mapped onto a second BPSK constellation, and the second BSPK constellation being rotated by 90° counter-clockwise relative to the first BPSK constellation; and

wherein the second symbol includes an indicator indicating Single User-Multiple Input Multiple Output (SU-MIMO) transmission or multi user-MIMO (MU-MIMO) transmission, and the third symbol includes a cyclic redundancy check (CRC) for the second symbol and, at least a portion of, the third symbol.

12. The method of claim 11 , wherein the method is performed by a processor, and the data frame is received by the processor from a wireless local area network transceiver.

13. The method of claim 11 , wherein the third symbol is immediately after the second symbol.

14. The method of claim 11 , wherein the data frame is a Physical Layer Convergence Procedure Protocol Data Unit (PPDU).

15. The method of claim 14 , wherein the PPDU omits a high throughput signal (HT_SIG) field between the legacy field and the VHT-SIG field.

16. The method of claim 11 , wherein the VHT-SIG field further includes a multiplexing number indicating a number of spatial streams.

17. The method of claim 11 , wherein the VHT-SIG field is immediately after the legacy field.

18. The method of claim 11 , wherein the second symbol is immediately after the first symbol.

19. The method of claim 11 , wherein:

the data frame is a PPDU;

the PPDU omits an HT_SIG field between the legacy field and the VHT-SIG field;

the second symbol is immediately after the first symbol; and

the third symbol is immediately after the second symbol.

20. An apparatus, comprising:

at least one wireless local area network transceiver;

at least one antenna, communicatively coupled to the local area network transceiver;

at least one processor;

at least one memory including computer program code, the memory and the computer program code configured to, working with the processor, cause the apparatus to perform at least the following:

receive, by the local area network transceiver, a Physical Layer Convergence Procedure Protocol Data Unit (PPDU), the PPDU being received by the local area network by way of the antenna, the PPDU comprising:

a legacy signal field including a first symbol that is mapped onto a first binary phase shift keying (BPSK) constellation;

a Very High Throughput Signal (VHT-SIG) field including a second symbol and a third symbol, the second symbol being mapped onto the first BPSK constellation, and the third symbol being mapped onto a second BPSK constellation, and the second BSPK constellation being rotated by 90° counter-clockwise relative to the first BPSK constellation; and

wherein the second symbol includes an indicator indicating Single User-Multiple Input Multiple Output (SU-MIMO) transmission or multi user-MIMO (MU-MIMO) transmission;

the third symbol includes a cyclic redundancy check (CRC) for the second symbol and, at least a portion of, the third symbol;

the PPDU omits an HT_SIG field between the legacy field and the VHT-SIG field;

the VHT-SIG field further includes a multiplexing number indicating a number of spatial streams;

the second symbol includes the multiplexing number indicating the number of spatial streams;

the VHT-SIG field is immediately after the legacy field;

the second symbol is immediately after the first symbol; and

the third symbol is immediately after the second symbol.