Method and apparatus for wide bandwidth mixed-mode wireless communications
View Patent ↗A network device for implementing high-rate greenfield transmission in a mixed mode frame structure. The network device is configured to transmit a mixed mode frame on two adjacent channels. The mixed mode frame comprises at least two backward compatible portions of a first frequency and a greenfield portion of a second frequency.
1. A communication device, comprising:
a backward compatible portion generator configured to:
generate a backward compatible portion of a mixed mode frame, and
generate a copy of the backward compatible portion; and
a greenfield generator configured to:
generate a greenfield portion of the mixed mode frame, and
generate a dummy length and a dummy rate for the backward compatible portion and the copy of the backward compatible portion based on the greenfield portion.
2. The communication device of claim 1 , wherein the backward compatible portion comprises a field containing timing information to instruct a receiver to ignore transmissions for a predetermined period of time.
3. The communication device of claim 2 , wherein the field containing the timing information is a signal field.
4. The communication device of claim 1 , wherein the backward compatible portion comprises:
a short training symbol;
a guard interval; and
a long training sequence.
5. The communication device of claim 4 , wherein the short training symbol is configured to be used by a receiver to detect the mixed mode frame.
6. The communication device of claim 4 , wherein the long training sequence is configured to be used by a receiver to train an equalizer.
7. The communication device of claim 1 , wherein the greenfield portion comprises:
a signal field;
a guard interval; and
a long training sequence.
8. The communication device of claim 1 , wherein the greenfield generator is configured to use a transmission length of the greenfield portion to generate the dummy length and the dummy rate for the backward compatible portion and the copy of the backward compatible portion.
9. The communication device of claim 1 , further comprising:
a symbol mapper coupled to the backward compatible portion generator, wherein the symbol mapper is configured to generate a symbol from coded bits for sub-carriers of an orthogonal frequency-division multiplexing (OFDM) sequence.
10. The communication device of claim 1 , further comprising:
an Inverse Fast Fourier Transform (IFFT) module; and
a digital filter.
11. The communication device of claim 1 , further comprising:
a transmitter configured to transmit the backward compatible portion, the copy of the backward compatible portion, and the greenfield portion.
12. The communication device of claim 11 , wherein the transmitter is configured to:
transmit the backward compatible portion at a first frequency over a first channel;
transmit the copy of the backward compatible portion at the first frequency over a second channel; and
transmit the greenfield portion at a second frequency.
13. The communication device of claim 12 , wherein the second channel is adjacent to the first channel.
14. The communication device of claim 1 , wherein the greenfield generator is further configured to:
instruct the backward compatible portion generator to generate the backward compatible portion such that a legacy device will stay off a channel for a length of a transmission of the greenfield portion.
15. A communication device, comprising:
a backward compatible portion generator configured to:
generate a backward compatible portion of a mixed mode frame based on a dummy length and a dummy rate, wherein the backward compatible portion contains timing information to instruct a receiver to ignore a transmission of a greenfield portion of the mixed mode frame, and
generate a copy of the backward compatible portion; and
a transmitter configured to:
transmit the backward compatible portion over a first channel,
transmit the copy of the backward compatible portion over a second channel, and
transmit the greenfield portion.
16. The communication device of claim 15 , wherein the second channel is adjacent to the first channel.
17. The communication device of claim 15 , further comprising:
a greenfield portion generator configured to:
generate the greenfield portion,
generate the dummy length and the dummy rate, and
provide the dummy length and the dummy rate to the backward compatible portion generator.
18. A method, comprising:
generating, using a first communication device, a backward compatible portion of a mixed mode frame based on a dummy length and a dummy rate, wherein the backward compatible portion contains timing information to instruct a second communication device to ignore a transmission of a greenfield portion of the mixed mode frame;
transmitting, using the first communication device, the backward compatible portion over a first channel;
transmitting, using the first communication device, the copy of the backward compatible portion over a second channel; and
transmitting, using the first communication device, the greenfield portion of the mixed mode frame.
19. The method of claim 18 , wherein the second channel is adjacent to the first channel.
20. The method of claim 18 , further comprising:
generating the greenfield portion; and
generating the dummy length and the dummy rate based on the greenfield portion.