Block based DMT systems with reduced redundancy

Abstract

There has been great interest in the design of DMT (discrete multitone) transceivers. An M-band DMT transceiver: is called block based if the transmitter and the receiver consist of constant matrices. The commonly used DMT systems are mostly block based, e.g., the DFT based system used in transmission over digital subscriber lines. For an FIR channel of order L, it is known that redundancy of length L enables the receiver to cancel ISI completely. Such a scheme allow us to trade bandwidth for ISI cancellation. In block based DMT (BDMT) systems, the redundancy K is typically chosen to be the same as the order of the channel L. In this paper we will consider BDMT transceiver with redundancy K less than or equal to L. With the reduced redundancy better bandwidth efficiency can be obtained as will be demonstrated by examples. Furthermore minimum redundancy for BDMT systems will be derived and the transceivers will be parameterized whenever ISI solutions exist.