  We consider a real-valued additive channel with an individual unknown noise
sequence. We present a simple sequential communication scheme based on the
celebrated Schalkwijk-Kailath scheme, which varies the transmit power according
to the power of the sequence, so that asymptotically the relation between the
SNR and the rate matches the Gaussian channel capacity 1/2 log(1+SNR)for almost
every noise sequence.
