Methods, systems, and devices for wireless communication are described. A user equipment (UE) may receive control signaling indicating a preamble configuration. The UE may receive a preamble in a time domain. The preamble may include a set of modulated bits during a first portion of an initial symbol duration of a slot. The set of modulated bits may include one or more of a first subset of network temporary identifier bits or a second subset of modulation and coding scheme (MCS) bits. The UE may process the preamble during a second portion of the initial symbol duration of the slot based on the preamble configuration.