  Cadambe and Jafar (CJ) alignment strategy for the K-user scalar
frequency-selective fading Gaussian channel, with encoding over blocks of 2n+1
random channel coefficients (subcarriers) is considered. The linear
zero-forcing (LZF) strategy is compared with a novel approach based on lattice
alignment and lattice decoding (LD). Despite both LZF and LD achieve the same
degrees of freedom, it is shown that LD can achieve very significant
improvements in terms of error rates at practical SNRs with respect to the
conventional LZF proposed in the literature. We also show that these gains are
realized provided that channel gains are controlled to be near constant, for
example, by means of power control and opportunistic carrier and user selection
strategies. In presence of relatively-small variations in the normalized
channel coefficient amplitudes, CJ alignment strategy yields very disappointing
results at finite SNRs, and the gain of LD over ZLF significantly reduces. In
light of these results, the practical applicability of CJ alignment scheme
remains questionable, in particular for Rayleigh fading channels, where channel
inversion power control yields to unbounded average transmit power.
