From: Precoded spatial multiplexing MIMO system with spatial component interleaver
ρ l
ρ 1
ρ 2
⋯
ρ i−1
ρ i
ρ i+1
ρ M−1
ρ M
ρ f(l)
ρ M−i+2
ρ M−i+1
ρ M−i