Null data packet (NDP) structure for secure sounding
Methods and apparatuses for arranging sounding symbol are provided. An example apparatus comprises memory; and processing circuitry coupled to the memory. The processing circuitry is configured to encode a sounding signal. The sounding signal comprises a plurality of sounding symbols, and the repetition of sounding symbols to be transmitted in sequence is avoided.
1. A device, the device comprising processing circuitry coupled to storage, the processing circuitry configured to:
determine a frame associated with a sounding signal, wherein the frame comprises a legacy preamble and one or more fields;
determine a first field comprising a plurality of sounding symbols, wherein the plurality of sounding symbols are associated with long training field (LTF) sequences;
apply a zero-prefix to each of the sounding symbols;
convert a first sounding symbol of the plurality of the sounding symbols to a first random sounding symbol by applying a first masking sequence to the first sounding symbol;
convert a second sounding symbol of the plurality of the sounding symbols to a second random sounding symbol by applying a second masking sequence to the second sounding symbol;
encode the sounding signal for two or more station devices, wherein the sounding signal comprises the first sounding symbol and the second sounding symbol; and
cause to send the frame comprising the sounding signal to the two or more station devices to perform a ranging procedure based on the plurality of sounding symbols.
2. The device of claim 1 , wherein the LTF sequences are based on applying a sequence of bits to each of the sounding symbols.
3. The device of claim 1 , wherein the processing circuitry is further configured to:
determine a first plurality of sounding symbols associated with a first user;
determine a second plurality of sounding symbols associated with a second user; and
cause to send the second plurality of sounding symbols after sending the first plurality of the second symbols.
4. The device of claim 1 , wherein the apparatus comprises two or more antennas, each of the antennas is to transmit encoded sounding symbols based on the plurality of sounding symbols.
5. The device of claim 1 , wherein the encoded sounding symbols are repeated.
6. The device of claim 1 , further comprising a transceiver configured to transmit and receive wireless signals.
7. The device of claim 6 , further comprising an antenna coupled to the transceiver to cause to send the frame.
8. A non-transitory computer-readable medium storing computer-executable instructions which when executed by one or more processors result in performing operations comprising:
determining a frame associated with a sounding signal, wherein the frame comprises a legacy preamble and one or more fields;
determining a first field comprising a plurality of sounding symbols, wherein the plurality of sounding symbols are associated with long training field (LTF) sequences;
applying a zero-prefix to each of the sounding symbols;
converting a first sounding symbol of the plurality of the sounding symbols to a first random sounding symbol by applying a first masking sequence to the first sounding symbol;
converting a second sounding symbol of the plurality of the sounding symbols to a second random sounding symbol by applying a second masking sequence to the second sounding symbol;
encoding the sounding signal for two or more station devices, wherein the sounding signal comprises the first sounding symbol and the second sounding symbol; and
causing to send the frame comprising the sounding signal to the two or more station devices to perform a ranging procedure based on the plurality of sounding symbols.
9. The non-transitory computer-readable medium of claim 8 , wherein the LTF sequences are based on applying a sequence of bits to each of the sounding symbols.
10. The non-transitory computer-readable medium of claim 8 , wherein the operations further comprise:
determining a first plurality of sounding symbols associated with a first user;
determining a second plurality of sounding symbols associated with a second user; and
causing to send the second plurality of sounding symbols after sending the first plurality of the second symbols.
11. The non-transitory computer-readable medium of claim 8 , wherein the apparatus comprises two or more antennas, each of the antennas is to transmit encoded sounding symbols based on the plurality of sounding symbols.
12. The non-transitory computer-readable medium of claim 8 , wherein the encoded sounding symbols are repeated.
13. A method comprising:
determining a frame associated with a sounding signal, wherein the frame comprises a legacy preamble and one or more fields;
determining a first field comprising a plurality of sounding symbols, wherein the plurality of sounding symbols are associated with long training field (LTF) sequences;
applying a zero-prefix to each of the sounding symbols;
converting a first sounding symbol of the plurality of the sounding symbols to a first random sounding symbol by applying a first masking sequence to the first sounding symbol;
converting a second sounding symbol of the plurality of the sounding symbols to a second random sounding symbol by applying a second masking sequence to the second sounding symbol;
encoding the sounding signal for two or more station devices, wherein the sounding signal comprises the first sounding symbol and the second sounding symbol; and
causing to send the frame comprising the sounding signal to the two or more station devices to perform a ranging procedure based on the plurality of sounding symbols.
14. The method of claim 13 , wherein the LTF sequences are based on applying a sequence of bits to each of the sounding symbols.