A second apparatus for wireless communication includes: a transceiver; and a processing circuit configured to receive, from a first apparatus via the transceiver, a physical layer protocol data unit (PPDU) including a first signal field having a fixed length and a second signal field having a variable length. The second signal field includes an orthogonal frequency-division multiplexing (OFDM) symbol block including at least one OFDM symbol, and one or more repetitions of the OFDM symbol block.