A method for wireless communications, comprising: generating a frame comprising a first portion and a second portion, said first portion being decodable by a first device operating according to a first protocol, said second portion not being decodable by the first device, wherein the first and second portions are decodable by a second device operating according to a second protocol; wherein generating the frame comprises generating a first subframe comprising the first and second portions, and generating a second subframe comprising a third portion and a fourth portion, the third portion being decodable by the first device operating according to the first protocol, the fourth portion not being decodable by the first device, and the third and fourth portions being decodable by the second device operating according to the second protocol; wherein generating the frame comprises configuring: the second portion to include a first set of frequency-domain pseudorandom binary sequence data configured for transmission via a first set of subcarriers of a first OFDM transmission; and the fourth portion to include a second set of frequency-domain pseudorandom binary sequence data configured for transmission via a second set of subcarriers of a second OFDM transmission; and wherein generating the frame comprises generating: the first set of frequency-domain pseudorandom binary sequence data based on a first seed for a particular primitive polynomial; and the second set of frequency-domain pseudorandom binary sequence data based on a second seed for the particular primitive polynomial; and outputting the frame for transmission, wherein outputting the frame for transmission comprises outputting the first and second sets of frequency-domain pseudorandom binary sequence data for transmission in a substantially time-aligned manner. generating a frame comprising a first portion and a second portion, said first portion being decodable by a first device operating according to a first protocol, said second portion not being decodable by the first device, wherein the first and second portions are decodable by a second device operating according to a second protocol; wherein generating the frame comprises generating a first subframe comprising the first and second portions, and generating a second subframe comprising a third portion and a fourth portion, the third portion being decodable by the first device operating according to the first protocol, the fourth portion not being decodable by the first device, and the third and fourth portions being decodable by the second device operating according to the second protocol; wherein generating the frame comprises configuring: the second portion to include a first set of frequency-domain pseudorandom binary sequence data configured for transmission via a first set of subcarriers of a first OFDM transmission; and the fourth portion to include a second set of frequency-domain pseudorandom binary sequence data configured for transmission via a second set of subcarriers of a second OFDM transmission; and the second portion to include a first set of frequency-domain pseudorandom binary sequence data configured for transmission via a first set of subcarriers of a first OFDM transmission; and the fourth portion to include a second set of frequency-domain pseudorandom binary sequence data configured for transmission via a second set of subcarriers of a second OFDM transmission; and wherein generating the frame comprises generating: the first set of frequency-domain pseudorandom binary sequence data based on a first seed for a particular primitive polynomial; and the second set of frequency-domain pseudorandom binary sequence data based on a second seed for the particular primitive polynomial; and the first set of frequency-domain pseudorandom binary sequence data based on a first seed for a particular primitive polynomial; and the second set of frequency-domain pseudorandom binary sequence data based on a second seed for the particular primitive polynomial; and outputting the frame for transmission, wherein outputting the frame for transmission comprises outputting the first and second sets of frequency-domain pseudorandom binary sequence data for transmission in a substantially time-aligned manner.