WLAN trigger frame padding for meeting minimum processing time requirement of receiver

A method for communication, comprising:

• in a Wireless Local-Area Network (WLAN) Access Point (AP) that comprises a Medium Access Control (MAC) processor, and a physical layer (PHY) processor, generating by the MAC processor a trigger frame comprising at least (i) one or more user information fields destined to one or more respective WLAN client stations (STAs) and (ii) a padding field comprising one or more padding bits;
• determining by the MAC processor a number of padding bits required that, after being inserted into the padding field and the trigger frame being encoded for transmission, satisfy a processing-time constraint imposed by the STAs, and inserting the determined number of padding bits required in the padding field;
• generating a packet from the trigger frame, by the PHY processor, including encoding the trigger frame containing the padding field in accordance with an Error Correction Code (ECC), into one or more Code Words (CWs) having a CW length that depends on a number of padding bits in the padding field, wherein the PHY processor is configured to encode the trigger frame with the ECC by applying a Low-Density Parity-Check (LDPC) code;
• generating by the PHY processor multiple modulated symbols from the one or more CWs of the packet;
• and
• transmitting the modulated symbols to the STAs, wherein the MAC processor is configured to determine the number of padding bits required based on calculating a first partial number of padding bits required for reaching an end of a CW which encodes a last user information field of the trigger frame;
• calculating a second partial number of padding bits required for reaching a far boundary of a symbol to which the last encoded bit of the CW that encodes a last user information field are mapped but not reaching the processing time constraint;
• calculating a third partial number of padding bits required for reaching the processing time constraint after the far boundary of the symbol to which the last encoded bit of the CW that encodes the last user information field is mapped;
• and summing the first partial number, second partial number, and the third partial number to determine the number of padding bits which reaches the processing constraint;
• wherein the first partial number of padding bits, the second partial number of padding bits and the third partial number of padding bits are calculated based on puncturing performed during the LDPC encoding of the trigger frame.