A communication apparatus includes a scalable N-point spectral transform block coupled to provide a transformed signal from a discrete multi-tone (DMT) modulated signal carrying digital data. A convolutional decoder is coupled to receive the transformed signal. The convolutional decoder is enabled only if N is less than a first pre-determined threshold. Digital data error decoding is applied if N is less than a second pre-determined threshold. In various embodiments, the convolutional decoder uses trellis coding. The digital data error decoder utilizes Reed-Solomon coding. The first and second pre-determined thresholds may be distinct thresholds. In one embodiment the first and second pre-determined thresholds are the same.