Discrete cosine transform in digital subscriber line applications

Multicarrier or multitone modulations (MTM) are efficient techniques for transmission of digital data over a copper wire. Most significant property of MTM is low sensitivity to the narrowband noise. All MTM are accomplished digitally. Due to high complexity, MTM transceivers were implemented at last decade, when suitable processors were manufactured. At present MTM have wide applications in digital subscriber lines (DSL). ANSI T1.413, asymmetric DSL (ADSL) standard and ITU G.992, defines discrete multitone modulation (DMT), known as well as orthogonal frequency division multiplexing (OFDM). We introduce a simple MTM modulation, which we call discrete cosine multitone (DCMT). DCMT possesses two important properties: it is more efficient than DMT, and provides lower complexity of a transceiver.