Apparatus, and an associated method, for selectably introducing desired levels of diversity into data communicated upon a radio communication channel to effectuate a communication service, such as a 1.times.EV-DV communication service. Responsive to channel conditions, the level of diversity is selected, and levels of encoding are utilized. Matching encoder and decoder apparatus are provided to sending and receiving station pairs. Encoder apparatus includes constituent encoder elements, and associated interleaver elements for interleaving data that is to be communicated by associated encoder elements. One, or more, antenna transducer elements are selectably utilized to provide spatial diversity in addition to temporal diversity.