Methods, systems, and devices for wireless communications are described. A user equipment (UE) may transmit a random access preamble to a base station as part of a two-step random access procedure. The UE may generate the preamble by identifying a discrete Fourier transform (DFT) matrix and generating a set of sequences based on the DFT matrix. Each sequence of the set of sequences may be generated by selecting a column of the DFT matrix and performing deterministic sampling of respective entries from the selected column in accordance with a sampling function. The UE may then select a sequence from the set of sequences based on generating the set of sequence. The UE may transmit the selected sequence to a wireless device (e.g., a base station).