# US 7,889,634 B1 · Method and apparatus for transmitting an OFDM signal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,889,634 B1 - Document ID: US7889634B1 - Status: Granted - Kind: B1 - Application number: 12/434,924 - Filed: 2009-05-04 - Granted: 2011-02-15 - Earliest claimed: 2005-02-14 - Assignees: Marvell International Ltd. - Inventors: Peter Loc - Web page: https://patentgrep.com/patent/US7889634B1 ## CPC - H04L 27/2602: {Signal structure} - H04L 27/2613: {Structure of the reference signals} - H04L 27/2647: {Arrangements specific to the receiver only (equalisation H04L27/01)} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract An apparatus includes a transmitter to transmit a first orthogonal frequency-division multiplexing signal including a first signal burst with a plurality of first fields of a first type. Each of a plurality of pair fields includes a second field of a second type and a third field of a third type. The second type is different than the first type and the third type is different than the first type and the second type. Each first field in the first signal burst is transmittable prior to a corresponding pair field of the plurality of pair fields. Each second field of a given pair field comprises an indicator to indicate whether a first field is transmitted subsequent to the given pair field. A controller selects a number of pair fields to be transmitted in the first signal burst of the first orthogonal frequency-division multiplexing signal. ## Claims ### Claim 1 An apparatus comprising: a transmitter configured to transmit a first orthogonal frequency-division multiplexing signal, the first orthogonal frequency-division multiplexing signal comprising a first signal burst, the first signal burst comprising a plurality of first fields of a first type, and a plurality of pair fields, each of the pair fields comprising a second field of a second type and a third field of a third type, the second type being different than the first type, the third type being different than the first type and the second type, wherein each of the first fields is transmittable prior to a corresponding one of the pair fields, and wherein the second field of one of the pair fields comprises an indicator to indicate (i) whether one of the first fields is transmitted subsequent to the one of the pair fields, and (ii) a duration of an inter-frame gap following the one of the pair fields; and a controller configured to select a first number of the pair fields to be transmitted in the first signal burst of the first orthogonal frequency-division multiplexing signal. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the controller selects a second number of the first fields to be transmitted in the first signal burst. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein the second number of the first fields to be transmitted in the first signal burst is less than the first number of the pair fields to be transmitted in the first signal burst. ### Claim 4 (depends on 1) The apparatus of claim 1, further comprising: a receiver configured to receive a second orthogonal frequency-division multiplexing signal responsive to the first orthogonal frequency-division multiplexing signal, the second orthogonal frequency-division multiplexing signal comprising information corresponding to a quality of reception of the first orthogonal frequency-division multiplexing signal, wherein the controller selects a second number of the pair fields to be transmitted in a second signal burst based on the information corresponding to the quality of reception of the first orthogonal frequency-division multiplexing signal. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein: each of the first fields comprises a preamble field; the second field of each of the pair fields comprises a signal field; and the third field of each of the pair fields comprises a payload field. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the apparatus is compliant with a standard selected from the group consisting of IEEE standards 802.11a, 802.11g, and 802.11n. ### Claim 7 (depends on 1) A device comprising the apparatus of claim 1. ### Claim 8 A method comprising: transmitting a first orthogonal frequency-division multiplexing signal, the first orthogonal frequency-division multiplexing signal comprising a first signal burst, the first signal burst comprising a plurality of first fields of a first type and a plurality of pair fields, each of the pair fields comprising a second field of a second type and a third field of a third type, the second type being different than the first type, the third type being different than the first type and the second type wherein each of the first fields is transmittable prior to a corresponding one of the pair fields, and wherein the second field of one of the pair fields comprises an indicator to indicate (i) whether one of the first fields is transmitted subsequent to the one of the pair fields, and (ii) a duration of an inter-frame gap following the one of the pair fields; and determining a first number of the pair fields to be transmitted in the first signal burst of the first orthogonal frequency-division multiplexing signal. ### Claim 9 (depends on 8) The method of claim 8, further comprising determining a second number of the first fields to be transmitted in the first signal burst. ### Claim 10 (depends on 9) The method of claim 9, wherein the second number of the first fields to be transmitted in the first signal burst is less than the first number of the pair fields to be transmitted in the first signal burst. ### Claim 11 An apparatus comprising: a transmitter configured to transmit a first orthogonal frequency-division multiplexing signal, the first orthogonal frequency-division multiplexing signal comprising a first signal burst, the first signal burst comprising a plurality of first fields of a first type, and a plurality of pair fields, each of the pair fields comprising a second field of a second type and a third field of a third type, the second type being different than the first type, the third type being different than the first type and the second type, wherein one of the first fields is transmittable prior to a corresponding one of the pair fields, and wherein the second field of one of the pair fields comprises an indicator to indicate whether one of the first fields is transmitted subsequent to the one of the pair fields; and a controller configured to select a first number of the pair fields to be transmitted in the first signal burst of the first orthogonal frequency-division multiplexing signal; and a receiver configured to receive a second orthogonal frequency-division multiplexing signal responsive to the first orthogonal frequency-division multiplexing signal, the second orthogonal frequency-division multiplexing signal comprising information corresponding to a quality of reception of the first orthogonal frequency-division multiplexing signal, wherein the controller selects a second number of the pair fields to be transmitted in a second signal burst based on the information corresponding to the quality of reception of the first orthogonal frequency-division multiplexing signal. ### Claim 12 A method comprising: transmitting a first orthogonal frequency-division multiplexing signal, the first orthogonal frequency-division multiplexing signal comprising a first signal burst, the first signal burst comprising a plurality of first fields of a first type, and a plurality of pair fields, each of the pair fields comprising a second field of a second type and a third field of a third type, the second type being different than the first type, the third type being different than the first type and the second type, wherein each of the first fields in the first signal burst is transmittable prior to a corresponding one of the pair fields, and wherein the second field of one of the pair fields comprises an indicator to indicate whether one of the first fields is transmitted subsequent to the one of the pair fields; determining a first number of the pair fields to be transmitted in the first signal burst of the first orthogonal frequency-division multiplexing signal; receiving a second orthogonal frequency-division multiplexing signal responsive to the first orthogonal frequency-division multiplexing signal, the second orthogonal frequency-division multiplexing signal comprising information corresponding to a quality of reception of the first orthogonal frequency-division multiplexing signal; and selecting a second number of the pair fields to be transmitted in a second signal burst based on the information corresponding to the quality of reception of the first orthogonal frequency-division multiplexing signal.