Practically Efficient Blind Speech Separation Using Frequency Band Selection Based on Magnitude Squared Coherence and a Small Dodecahedral Microphone Array

Table 2

Computational complexity.

Method	Complexity
STFT (forward and inverse)	2𝒪(𝑁𝑀𝑁𝐿𝑁𝐹log2𝑁𝐹)
Covariance matrix	𝒪(𝑁^2𝑀𝑁𝐿𝑁𝐵)
Eigenvalue decomposition	𝒪(4𝑁^3𝑀/3+3𝑁^3𝑀𝑁𝐵)
Subspace method	𝒪(𝑁𝑄𝑁𝑀𝑁𝐿𝑁𝐵)
Separation matrix	𝒪(𝑁^3𝑄𝑁𝐼𝑁𝐵)
Projection method	𝒪(4𝑁^3𝑀/3+3𝑁^3𝑀𝑁𝐵)
Hierarchical clustering	𝒪({𝑁𝑀𝑁𝐾(𝑘)𝑁𝐵}^2)