A signal processing device includes an acquisition unit that acquires identification information associated with data obtained by decoding a reception signal that includes a signal included in a first layer and a signal included in a different layer and superimposed on the signal of the first layer in a power axis direction, the data being output to a post-stage processing unit, a decoding unit that decodes the signal of the different layer on the basis of a result of decoding of the signal of the first layer after the decoding of the signal of the first layer, and an output control unit that outputs data obtained by decoding the signal of the different layer to the post-stage processing unit without outputting data obtained by decoding the signal of the first layer to the post-stage processing unit, in a case where data identified by the identification information is data obtained by decoding the signal of the different layer.