At least in Europe, when broadcasting went digital (DVB-T), a lot of cities started being covered by single frequency network transmission, which specifically leverages different transmitter locations transmitting the same signal to decrease dead zones.

Due to how OFDM works, I suppose the idea here is to intentionally send a heterogeneous signal on a few non-overlapping subcarriers (for single-frequency networks) or on different transponders at different locations (since single frequency networks aren't as common in the US due to how broadcasting evolved there, although ATSC 3.0 apparently also allows single frequency networks).