In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may determine a TDD frame structure of a group of TDD frame structures for narrowband communications. The apparatus may transmit a series of repetitions of a narrowband physical downlink channel using the narrowband TDD frame structure. In one aspect, a first portion of repetitions from the series of repetitions may be transmitted in one or more first sets of downlink subframes using a first scrambling sequence. In one aspect, a second portion of repetitions from the series of repetitions may be transmitted in one or more second sets of downlink subframes using a second scrambling sequence.