On The Equivalence of Single - and Multicarrier Modulation : A New ViewRobert

| Starting from the optimization of multi-carrier systems the equivalence to single{carrier systems is shown with respect to the achievable signal{ to{noise ratio. This provides a new view on the topic. I. Introduction For many applications multicarrier modulation, often also denoted as discrete multitone (DMT) or orthogonal frequency division multiplexing (OFDM), is a strong competitor to single{carrier modulation. In 5] it is shown, that in principle DMT and pulse amplitude modulation with decision{feedback equalization (PAM{DFE) can achieve the same transmission rate (see also 1]). In this paper the equivalence of DMT and PAM{DFE is derived from a new point of view, based on the optimization of DMT. II. Transmission Model and PAM{DFE Consider the T {spaced (possibly complex{valued) discrete{ time model of a digital PAM transmission scheme including transmit lter, continuous{time channel and optimum linear zero{forcing (LZF) equalization. The overall discrete{time description is simply given by the additive Gaussian noise channel with a certain noise power density spectrum nn(e j2f T). It is well known that a whitening lter H(z) can be applied in order to decrease noise variance by prediction. As the order of H(z) goes to innnity, noise becomes white with variance