US Patent 10462790 OFDMA with block tone assignment for WLAN

An access point (AP) device of a wireless local area network (WLAN) assigns a plurality of different orthogonal frequency division multiplexing (OFDM) sub-channel blocks to a plurality of client stations that are members of the WLAN. The AP device receives respective independent data for the plurality of client stations, and generates an orthogonal frequency division multiple access (OFDMA) data unit that includes a preamble and, for each sub-channel block in the plurality of OFDM sub-channel blocks: a respective legacy portion of the preamble that spans only the OFDM sub-channel block, the legacy portion including a respective legacy signal field that indicates a duration of the OFDMA data unit, a respective non-legacy signal field in the preamble, the respective non-legacy signal field spanning only the OFDM sub-channel block, and respective independent data for a respective client station, the respective independent data included within the OFDM sub-channel block.