60 GHz physical layer convergence protocol (PLCP) protocol data unit (PPDU) formats
This disclosure provides methods, devices and systems for increasing carrier frequencies for wireless communications in wireless local area networks (WLANs). Some implementations more specifically relate to packet designs that support wireless communications on carrier frequencies above 7 GHz. In some aspects, a wireless communication device may map a physical layer convergence protocol (PLCP) protocol data unit (PPDU) to orthogonal subcarriers according to existing tone plans associated with carrier frequencies below 7 GHz and may up-clock the PPDU for transmission on carrier frequencies above 7 GHz (such as by increasing the frequency of a clock signal used to convert the PPDU between the frequency domain and the time domain). In some implementations, the PPDU may conform to an existing PPDU format designed for sub-7 GHz wireless communications. In some other implementations, the PPDU may conform to a “green field” PPDU format optimized for wireless communications on carrier frequencies above 7 GHz.
1. A method for wireless communication performed by a wireless communication device, comprising:
mapping a first portion of a physical layer (PHY) preamble of a PHY protocol data unit (PPDU) to a first number of data subcarriers in accordance with a first sub-7 GHz PPDU tone plan that comprises N subcarriers including the first number of data subcarriers, the first portion including a legacy short training field (L-STF), a legacy long training field (L-LTF), and one or more signal (SIG) fields;
transforming the N subcarriers into a first time-varying signal using an N-point inverse fast Fourier transform (IFFT) and a sampling rate (f s ) that is equal to a bandwidth (BW) associated with transmission of the PPDU on a carrier frequency above 7 GHz such that a first subcarrier spacing (SCS) associated with the first portion of the PHY preamble is greater than 1.2 MHz; and
transmitting the PPDU including the first time-varying signal on the carrier frequency that is above 7 GHz.
2. The method of claim 1 , wherein the first portion of the PHY preamble further includes a non-legacy SIG field immediately following L-SIG.
3. The method of claim 1 , wherein the PPDU consists of only the first portion of the PHY preamble.
4. The method of claim 1 , further comprising:
mapping, to a number (M) of subcarriers, a second portion of the PPDU including at least a data field, a packet extension, or one or more training fields (TRNs);
transforming the M subcarriers into a second time-varying signal at the sampling rate f s ; and
transmitting the second time-varying signal immediately following the first time-varying signal.
5. The method of claim 4 , wherein the one or more SIG fields consist of a single SIG field that is immediately followed by the data field, the packet extension, or the one or more TRNs.
6. The method of claim 4 , wherein the second portion of the PPDU further includes one or more additional LTFs.
7. The method of claim 6 , wherein the one or more SIG fields consist of a single SIG field that is immediately followed by the one or more additional LTFs.
8. The method of claim 4 , wherein M>N.
9. The method of claim 8 , wherein the first portion of the PPDU is duplicated for transmission on a number (n) of sub-bands each spanning a respective bandwidth portion equal to BW/n, where BW=f s .
10. The method of claim 9 , wherein the transformation of the M subcarriers into the second time-varying signal results in a second SCS equal to the first SCS, the second SCS representing an amount of separation, in a frequency domain, between adjacent subcarriers of the M subcarriers.
11. The method of claim 9 , wherein the transformation of the M subcarriers into the second time-varying signal results in a second SCS different than the first SCS, the second SCS representing an amount of separation, in a frequency domain, between adjacent subcarriers of the M subcarriers.
12. The method of claim 9 , wherein the L-LTF is transmitted on the same subcarriers as the second portion of the PPDU as a result of duplicating the first portion of the PHY preamble of the PPDU for transmission on the n sub-bands.
13. The method of claim 1 , wherein the L-LTF includes a first OFDM symbol and a second OFDM symbol identical to the first OFDM symbol.
14. The method of claim 1 , wherein the L-LTF includes a first OFDM symbol and a second OFDM symbol, the method further comprising:
applying a P-matrix to the L-LTF so that the first OFDM symbol is different than the second OFDM symbol.
15. The method of claim 1 , wherein the L-STF comprises a Golay sequence.
16. The method of claim 1 , wherein information carried in the one or more SIG fields includes an indication of whether the PPDU is associated with a beamforming training operation.
17. The method of claim 1 , wherein:
the PPDU further includes a data field and the method further includes mapping the data field to a second number of data subcarriers in accordance with a second sub-7 GHz PPDU tone plan that comprises M subcarriers including the second number of data subcarriers,
N is equal to 64,
M is equal to 256,
the BW is equal to 20*X MHz,
the first portion of the PHY preamble is duplicated in each of 4 sub-bands within the BW and upclocked by a factor of X/4,
each sub-band has a bandwidth of 5*X MHz, and
the data field is upclocked by a factor of X.
18. The method of claim 17 , wherein the L-STF is mapped to only every 4 th data subcarrier of the first number of data subcarriers while the L-LTF and one or more L-SIG fields are mapped to every data subcarrier of the first number of data subcarriers.
19. The method of claim 17 , wherein the first sub-7 GHz tone plan conforms to an IEEE 802.11ac 20 MHz tone plan and the second sub-7 GHz tone plan conforms to an IEEE 802.11be 20 MHz tone plan.
20. The method of claim 1 , wherein:
the PPDU further includes a data field and the method further includes mapping the data field to a second number of data subcarriers in accordance with a second sub-7 GHz PPDU tone plan that comprises M subcarriers including the second number of data subcarriers,
N is equal to 64,
M is equal to 256,
the BW is equal to 80*X MHz,
the first portion of the PHY preamble is duplicated in each of 4 sub-bands within the BW,
each sub-band has a bandwidth of 20*X MHz, and
the data field is upclocked by a factor of X.
21. The method of claim 20 , wherein the L-STF is mapped to only every 4 th data subcarrier of the first number of data subcarriers while the L-LTF and one or more L-SIG fields are mapped to every data subcarrier of the first number of data subcarriers.
22. The method of claim 20 , wherein the first sub-7 GHz tone plan conforms to an IEEE 802.11ac 20 MHz tone plan and the second sub-7 GHz tone plan conforms to an IEEE 802.11ac 80 MHz tone plan.
23. A wireless communication device comprising:
at least one memory; and
at least one processor communicatively coupled with the at least one memory, the at least one processor configured to cause the wireless communication device to:
map a first portion of a physical layer (PHY) preamble of a PHY protocol data unit (PPDU) to a first number of data subcarriers in accordance with a first sub-7 GHz PPDU tone plan that comprises N subcarriers including the first number of data subcarriers, the first portion including a legacy short training field (L-STF), a legacy long training field (L-LTF), and one or more signal (SIG) fields;
transform the N subcarriers into a first time-varying signal using an N-point inverse fast Fourier transform (IFFT) and a sampling rate (f s ) that is equal to a bandwidth (BW) associated with transmission of the PPDU on a carrier frequency above 7 GHz such that a first subcarrier spacing (SCS) associated with the first portion of the PHY preamble is greater than 1.2 MHz; and
transmit the PPDU including the first time-varying signal on the carrier frequency that is above 7 GHz.
24. The wireless communication device of claim 23 , wherein:
the PPDU further includes a data field and the at least one processor is further configured to cause the wireless communication device to map the data field to a second number of data subcarriers in accordance with a second sub-7 GHz PPDU tone plan that comprises M subcarriers including the second number of data subcarriers,
N is equal to 64,
M is equal to 256,
the BW is equal to 20*X MHz,
the first portion of the PHY preamble is duplicated in each of 4 sub-bands within the BW and upclocked by a factor of X/4,
each sub-band has a bandwidth of 5*X MHz, and
the data field is upclocked by a factor of X.
25. The wireless communication device of claim 23 , wherein:
the PPDU further includes a data field and the at least one processor is further configured to cause the wireless communication device to map the data field to a second number of data subcarriers in accordance with a second sub-7 GHz PPDU tone plan that comprises M subcarriers including the second number of data subcarriers,
N is equal to 64,
M is equal to 256,
the BW is equal to 80*X MHz,
the first portion of the PHY preamble is duplicated in each of 4 sub-bands within the BW,
each sub-band has a bandwidth of 20*X MHz, and
the data field is upclocked by a factor of X.
26. A method of wireless communication performed by a wireless communication device comprising:
mapping a first portion of a physical layer (PHY) preamble of a PHY protocol data unit (PPDU) to a number (N) of subcarriers, the first portion including a short training field (STF) and one or more signal (SIG) fields carrying information for interpreting the PPDU;
mapping a second portion of the PHY preamble that includes a long training field (LTF) to a number (M) of subcarriers, where M>N;
transforming the N subcarriers and the M subcarriers to a time-varying signal; and
transmitting the PPDU including the time-varying signal on a carrier frequency above 7 GHz.
27. The method of claim 26 , further comprising:
mapping, to the M subcarriers, at least a data field, a packet extension, or one or more other training fields (TRNs) of the PPDU.
28. The method of claim 26 , wherein the N subcarriers and the M subcarriers are transformed to the time-varying signal at a sampling rate (f s ) associated with a subcarrier spacing (SCS) greater than 1.2 MHz, the SCS representing an amount of separation, in a frequency domain, between adjacent subcarriers of the N subcarriers.
29. Method of claim 28 , wherein the first portion of the PPDU is duplicated for transmission on a number (n) of sub-bands each spanning a respective bandwidth portion of a bandwidth over which the PPDU is transmitted.
30. A wireless communication device comprising:
at least one memory; and
at least one processor communicatively coupled with the at least one memory, the at least one processor configured to cause the wireless communication device to:
map a first portion of a physical layer (PHY) preamble of a PHY protocol data unit (PPDU) to a number (N) of subcarriers, the first portion including a short training field (STF) and one or more signal (SIG) fields carrying information for interpreting the PPDU;
map a second portion of the PHY preamble that includes a long training field (LTF) to a number (M) of subcarriers, where M>N;
transform the N subcarriers and the M subcarriers to a time-varying signal; and
transmit the time-varying signal.