In a method for detecting a packet type of an orthogonal frequency division multiplexing (OFDM) data unit detected in a communication channel, a first estimate and a second estimate of a transmitted symbol are determined for each of at least some of a plurality of OFDM tones in an OFDM symbol of the data unit. A first distance and a second distance are determined between a received symbol and, respectively, the first estimate and the second estimate scaled by a channel response estimate corresponding to the OFDM tone. A first total distance is determined based on a mathematical summation of the first distances over the plurality of OFDM tones. A second total distance is determined based on a mathematical summation of the second distances over the plurality of OFDM tones. The packet type is determined based at least on the first total distance and the second total distance.