Methods, systems, and devices for wireless communication are described. A wireless device may use a sampling rate that is less than a default sampling rate associated with a wireless carrier. The device may operate in a narrowband portion of a system bandwidth, and the sampling rate may be less than that used by devices monitoring the whole bandwidth. Multiple sampling rates may be used so that a portion of signal processing may be associated with one sampling rate and another portion of the signal processing may be associated with another sampling rate. The size of a cyclic prefix (CP) may be adjusted based on the sampling rate to align subframe timing boundaries for signals of different sampling rates. In some cases, each symbol of a signal may include both a CP and a postfix such that the postfix for each symbol overlaps the prefix of the next symbol.