  In this paper, we show that by investigating inherent time delays between
different users in a multiuser scenario, we are able to cancel interference
more efficiently. Time asynchrony provides another tool to cancel interference
which results in preserving other resources like frequency, time and code.
Therefore, we can save the invaluable resource of frequency band and also
increase spectral efficiency. A sampling method is presented which results in
independent noise samples and obviates the need for the complex process of
noise whitening. By taking advantage of this sampling method and its unique
structure, we implement maximum-likelihood sequence detection which outperforms
synchronous maximum-likelihood detection. We also present successive
interference cancellation with hard decision passing which gives rise to a
novel forward-backward belief propagation method. Next, the performance of zero
forcing detection is analyzed. Simulation results are also presented to verify
our analysis.
