Embodiments of master station and method for high-efficiency WLAN (HEW) communication are generally described herein. In some embodiments, the master station is configured for HEW communication in accordance with an IEEE 802.11ax technique. The master station may transmit an indication to one or more of a plurality of HEW stations to indicate which one of a plurality of 20 MHz channels to monitor for a HEW signal field. The master station may configure the HEW signal field to indicate which of a plurality of subchannels of the indicated 20 MHz channel is allocated to the HEW stations for communication. The master station may transmit the configured HEW signal field in the indicated one of the 20 MHz channels and may communicate with the HEW stations on the indicated subchannels in accordance with an orthogonal-frequency divisional multiple access (OFDMA) technique.