Support for additional decoding processing time in wireless lan systems

A wireless communication device comprising:

• a wireless receiver,
• a wireless transmitter, and
• a processor coupled to the wireless receiver and to the wireless transmitter, wherein the processor is configured to:
• receive a first High Efficiency Physical Layer Protocol Data Unit (HE PPDU) including a second HE PPDU including a Non-High-Throughput (Non-HT) signal (L-SIG) field, a High Efficiency signal (HE-SIG) field, and a data field, wherein the data field includes an Orthogonal Frequency Division Multiplexing (OFDM) symbol including padding bits, and the first HE PPDU further includes an extension appended at an end of the second HE PPDU to increase an available processing time, the extension having a non-zero signal strength;
• and
• transmit an Acknowledgement frame a predetermined inter-frame space after the end of the first HE PPDU,
• wherein the L-SIG field includes a first length indication of the first HE PPDU, and
• wherein the HE-SIG field includes a second length indication for a duration of the extension to avoid ambiguity of the extension.