  The paper proposes a new technique that substantially improves blind digital
modulation identification (DMI) algorithms that are based on higher-order
statistics (HOS). The proposed technique takes advantage of noise power
estimation to make an offset on higher-order moments (HOM), thus getting an
estimate of noise-free HOM. When tested for multiple-antenna systems, the
proposed method outperforms other DMI algorithms, in terms of identification
accuracy, that are based only on cumulants or do not consider HOM denoising,
even for a receiver with impairments. The improvement is achieved with the same
order of complexity of the common HOS-based DMI algorithms in the same context.
