In this paper we intend to present the concept of superframes and its use, primarily, in multiplexing techniques. The signal are supposed band limited and three multiplexing schemes are considered: time division multiple access, frequency division multiple access and frequency hoping multiple access (FHMA). The first two schemes give rise to tight superframes, whereas for FHMA, the associated superframes are more complex. For some such superframes the dual superframe is obtained in closed form. An example of a FHMA scheme is also presented.