A data retransmission request device, a data transmitter, and a data retransmission method for multi-tone systems

摘要

In a multi-tone data transmission system, data are modulated on a set of M tones for being transmitted between a transmitter (110) and a receiver (120). According to the invention, the data retransmission request device (124) in such system is adapted to request retransmission of a data transmission unit (22) that is hierarchically modulated at a particular hierarchical level (L3). The transmitter (110) can de-activate a number of lowest hierarchical levels based on the number or rate of received retransmission requests.