Cyclic shift delay (CSD) short training field (STF) for orthogonal frequency division multiplexing (OFDM) signaling within multiple user, multiple access, and/or MIMO wireless communicaitons
View Patent ↗Cyclic shift delay (CSD) short training field (STF) for use within multiple user, multiple access, and/or MIMO wireless communications. Appropriately designed CSD STF is applied to communications in wireless communication systems thereby ensuring a minimized power error difference between respective portions of a packet transmitted therein. A first portion of the packet may be a short training field (STF) and a second portion of the packet may be a payload (e.g., a data portion). By applying such appropriately designed CSD STF to a packet, a wireless communication device that receives a signal corresponding to that packet need not perform extra or very significant backoff (e.g., with respect to a signal subsequent to automatic gain control (AGC) processing) thereby simplifying processing of that signal and potentially also reducing a total number of effective analog to digital converter (ADC) bits needed to represent a digitally sampled version of that signal.
1. A method for operating a wireless communication device, the method comprising:
generating a packet including a cyclic shift delayed (CSD) short training field (STF) and a payload in accordance with a plurality of CSDs, each of the plurality of CSDs being a respective integer multiple of a time period, for minimizing difference between a first power associated with the CSD STF and a second power associated with the payload; and
via a plurality of antennae, transmitting a signal including the packet to a plurality of wireless communication devices such that each of the plurality of antennae transmitting at a respective time in accordance a respective one of the plurality of CSDs.
2. The method of claim 1 , wherein:
the packet being a multi-user packet; and further comprising:
via the plurality of antennae, transmitting the signal including the multi-user packet to the plurality of wireless communication devices after transmitting at least one additional signal including a management frame to the plurality of wireless communication devices; and
generating the management frame indicating for which of the plurality of wireless communication devices the multi-user packet being intended and indicating a plurality of streams by which the multi-user packet being transmitted.
3. The method of claim 1 , wherein:
the plurality of CSDs being compliant in accordance with a first communication protocol; and
the plurality of CSDs being backward compliant in accordance with a second communication protocol being a legacy communication protocol relative to the first communication protocol.
4. The method of claim 3 , wherein:
all of the plurality of CSDs corresponding to the first communication protocol; and
a subset of the plurality of CSDs corresponding to the second communication protocol.
5. The method of claim 1 , further comprising:
employing all of the plurality of CSDs when transmitting the signal using all of the plurality of antennae; and
employing a subset of the plurality of CSDs when transmitting the signal using less than all of the plurality of antennae.
6. The method of claim 1 , wherein:
the wireless communication device being an access point (AP); and
the plurality of wireless communication devices being a plurality of wireless stations (STAs).
7. An apparatus, comprising:
a baseband processing module to generate a packet including a cyclic shift delayed (CSD) short training field (STF) and a payload in accordance with a plurality of CSDs to minimize difference between a first power associated with the CSD STF and a second power associated with the payload; and
a plurality of antennae to transmit a signal including the packet to a plurality of wireless communication devices; and wherein:
each of the plurality of CSDs being a respective integer multiple of a time period; and
each of the plurality of antennae to transmit at a respective time in accordance a respective one of the plurality of CSDs.
8. The apparatus of claim 7 , wherein:
the packet being a multi-user packet;
a first portion of the multi-user packet being intended for a first of the plurality of wireless communication devices; and
a second portion of the multi-user packet being intended for a second of the plurality of wireless communication devices.
9. The apparatus of claim 7 , wherein:
the packet being a multi-user packet;
the plurality of antennae transmitting the signal including the multi-user packet to the plurality of wireless communication devices after the plurality of antennae transmitting at least one additional signal including a management frame to the plurality of wireless communication devices; and
the baseband processing module generating the management frame indicating for which of the plurality of wireless communication devices the multi-user packet being intended and indicating a plurality of streams by which the multi-user packet being transmitted.
10. The apparatus of claim 7 , wherein:
the plurality of CSDs being compliant in accordance with a first communication protocol; and
the plurality of CSDs being backward compliant in accordance with a second communication protocol being a legacy communication protocol relative to the first communication protocol.
11. The apparatus of claim 10 , wherein:
all of the plurality of CSDs corresponding to the first communication protocol; and
a subset of the plurality of CSDs corresponding to the second communication protocol.
12. The apparatus of claim 7 , wherein:
the time period being 50 nano-seconds, 25 nano-seconds, or 12.5 nano-seconds; and
each of plurality of CSDs being in a range of 0 nano-seconds to 800 nano-seconds, inclusive.
13. The apparatus of claim 7 , wherein:
the time period being 50 nano-seconds, 25 nano-seconds, or 12.5 nano-seconds; and
each of plurality of CSDs being in a range of 0 nano-seconds to 200 nano-seconds, inclusive.
14. The apparatus of claim 7 , wherein:
all of the plurality of CSDs being employed when transmitting the signal using all of the plurality of antennae; and
a subset of the plurality of CSDs being employed when transmitting the signal using less than all of the plurality of antennae.
15. The apparatus of claim 7 , wherein:
the apparatus being an access point (AP); and
the plurality of wireless communication devices being a plurality of wireless stations (STAs).
16. An apparatus, comprising:
a baseband processing module to generate:
a management frame indicating for which of a plurality of wireless communication devices a multi-user packet being intended and indicating a plurality of streams by which the multi-user packet being transmitted; and
the multi-user packet including a cyclic shift delayed (CSD) short training field (STF) and a payload in accordance with a plurality of CSDs for minimizing difference between a first power associated with the CSD STF and a second power associated with the payload; and
a plurality of antennae to transmit:
a first signal including the management frame to the plurality of wireless communication devices; and
a second signal including the multi-user packet to the plurality of wireless communication devices; and wherein:
each of the plurality of CSDs being a respective integer multiple of a time period;
each of the plurality of antennae to transmit at a respective time in accordance a respective one of the plurality of CSDs;
a first portion of the multi-user packet being intended for a first of the plurality of wireless communication devices; and
a second portion of the multi-user packet being intended for a second of the plurality of wireless communication devices.
17. The apparatus of claim 16 , wherein:
the plurality of CSDs being compliant in accordance with a first communication protocol; and
the plurality of CSDs being backward compliant in accordance with a second communication protocol being a legacy communication protocol relative to the first communication protocol.
18. The apparatus of claim 17 , wherein:
all of the plurality of CSDs corresponding to the first communication protocol; and
a subset of the plurality of CSDs corresponding to the second communication protocol.
19. The apparatus of claim 16 , wherein:
all of the plurality of CSDs being employed when transmitting the signal using all of the plurality of antennae; and
a subset of the plurality of CSDs being employed when transmitting the signal using less than all of the plurality of antennae.
20. The apparatus of claim 16 , wherein:
the apparatus being an access point (AP); and
the plurality of wireless communication devices being a plurality of wireless stations (STAs).