A DVB-T receiver includes a channel equalizer, a metric assignment and demapping circuit, a Viterbi decoder and an outer Reed-Solomon decoder. The metric assignment and demapping circuit includes a soft-decision quantising arrangement which provides confidence values for the Viterbi decoder. The quantising arrangement receives a control input from channel state indication (CSI) measurement circuitry.
A further channel state indication is obtained on a symbol-by-symbol basis. This is compared an average obtained over a few symbols, to detect impulsive interference, and applied as part of the control for the soft-decision quantiser.
A signal derived from the further channel state indication is also applied to the erasures input of the Reed-Solomon decoder.