Methods, systems, and devices for wireless communications are described. A receiving device and a transmitting device may utilize index modulation for full-duplex operations. The transmitting device, such as a base station or a user equipment (UE), may define blocks of resource elements (REs) for transmissions. The transmitting device may then transmit a power boosted index modulated signal at a data RE location within a resource allocation and may skip transmitting within the remaining REs of the resource allocation. The transmitting device may indicate the number of REs per RE block to the receiving device (e.g., a UE). The receiving device may use this information to perform energy detection for determining which REs within an RE block include the power boosted index modulated transmission and which REs within the RE block are empty REs. In some cases, the receiving device may use the empty REs for performing noise estimation.