# US 2014/0153487 A1 · Method and Apparatus for Wide Bandwidth Mixed-Mode Wireless Communications > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153487 A1 - Document ID: US20140153487A1 - Status: Published application - Kind: A1 - Application number: 14/094,107 - Filed: 2013-12-02 - Published: 2014-06-05 - Earliest claimed: 2004-07-27 - Assignees: Broadcom Corporation - Applicants: Broadcom Corporation - Inventors: Jason Alexander TRACHEWSKY - Web page: https://patentgrep.com/patent/US20140153487A1 ## CPC - H04L 27/2634: {Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation} - H04B 7/0697: {using spatial multiplexing} - H04B 7/12: Frequency diversity - H04L 27/01: Equalisers {(baseband equalizers at the transmitter end H04L25/03343; in analogue transmission systems H04B3/04, H04B7/005)} - H04L 27/2618: {Reduction thereof using auxiliary subcarriers} - H04L 27/2601: {Multicarrier modulation systems} - H04W 88/06: adapted for operation in multiple networks {or having at least two operational modes}, e.g. multi-mode terminals - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract 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. ## Claims ### Claim 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. ### Claim 2 (depends on 1) 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. ### Claim 3 (depends on 2) The communication device of claim 2, wherein the field containing the timing information is a signal field. ### Claim 4 (depends on 1) The communication device of claim 1, wherein the backward compatible portion further comprises: a short training symbol; a guard interval; and a long training sequence. ### Claim 5 (depends on 4) 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. ### Claim 6 (depends on 4) The communication device of claim 4, wherein the long training sequence is configured to be used by a receiver to train an equalizer. ### Claim 7 (depends on 1) The communication device of claim 1, wherein the greenfield portion comprises: a signal field; a guard interval; and a long training sequence. ### Claim 8 (depends on 1) 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. ### Claim 9 (depends on 1) 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. ### Claim 10 (depends on 1) The communication device of claim 1, farther comprising: an Inverse Fast Fourier Transform (IFFT) module; and a digital filter. ### Claim 11 (depends on 1) 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. ### Claim 12 (depends on 11) 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. ### Claim 13 (depends on 12) The communication device of claim 12, wherein the second channel is adjacent to the first channel. ### Claim 14 (depends on 1) 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 of a channel for a length of a transmission of the greenfield portion. ### Claim 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. ### Claim 16 (depends on 15) The communication device of claim 15, wherein the second channel is adjacent to the first channel. ### Claim 17 (depends on 15) 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. ### Claim 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, a greenfield portion of the mixed mode frame. ### Claim 19 (depends on 18) The method of claim 18, wherein the second channel is adjacent to the first channel. ### Claim 20 (depends on 18) 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.