Methods, systems, and devices for wireless communication are described that provide for synchronization signal (SS) blocks in which synchronization signals and broadcast channel transmissions may be transmitted. Broadcast channel transmissions may be demodulated using SS transmissions, reference signal transmissions, or combinations thereof. Broadcast channel transmissions may be transmitted in a subset of SS block time resources, and synchronization signals may be transmitted in another subset of SS block time resources. Reference signals may be transmitted using tones within the broadcast channel time resources, and may be transmitted at a higher density for portions of the broadcast channel transmission bandwidth that are outside of the SS transmission bandwidth. Waveforms for reference signal transmissions, and information provided by reference signal transmissions may be provided.