Coding and modulation under power constraints

An issue arising at the physical layer in digital wireless transmission is the choice of the coding/modulation scheme taking into account the availability of a limited energy source. This article is devoted to a description of the rationales behind this choice. As the latter depends on the channel model, we examine four of these, namely, the Gaussian channel, the independent-fading channel, the block-fading channel, and a channel where the transmission quality is limited by interference rather than by noise. Code selection and power-allocation strategies are discussed.