Multicarrier transmission system receiver

The receiver includes a digitiser which samples and quantises a received signal with several individual carriers. A processor digitally processes the sampled signal. Data modulated on the several carriers is extracted. The digitiser has an AD converter which converts the received signal to a series of digitised samples, each of which n bits. An extremal detector detects when an analogue signal at an input to the converter has an amplitude greater than the amplitude which can be represented by n bits. The generator is controlled by the extremal detector to generate m bits to represent each digitised sample, where m is greater than n.