Methods, systems, and devices for wireless communication are described. Generally, the described techniques provide for increasing the chances that a high reliability packet scheduled to be transmitted in a shared radio frequency spectrum is received by a receiving device. In one example, a wireless device (e.g., a base station or a user equipment (UE)) may duplicate a packet at a packet data convergence protocol (PDCP) layer for transmission on multiple listen before talk (LBT) subchannels of a carrier to improve reliability. In another example, a wireless device may duplicate a packet at a physical (PHY) layer for transmission on multiple LBT subchannels of a carrier to improve reliability, or the wireless device may encode and map the packet to multiple LBT subchannels of a carrier for transmission on the multiple LBT subchannels to improve reliability.