Methods, systems, and devices for wireless communications are described. In accordance with the described techniques, communicating devices (e.g., an encoder and decoder) may apply an orthogonal cover code to a polar codeword to reduce cross-correlation between different codewords. For example, such techniques may reduce power consumption at a decoding device by providing for earlier decoding termination (e.g., as a result of the reduced cross-correlation). Techniques for generating the cover codes (e.g., on a per-aggregation level basis) and applying the cover codes (e.g., within a search space) are described. Additionally or alternatively, the described techniques may relate to seeding of reference signals used to support decoding of the codewords. Improved orthogonality between reference signal seeds may further suppress codeword recipient ambiguity.