Low-Complexity Inverse Square Root Approximation for Baseband Matrix Operations

Algorithm 1

(1) for  𝑘=1∶𝑛

(2)  𝐑_𝑘,𝑘=‖𝐇_{1∶𝑛,𝑘}‖

(3)  𝐐_{1∶𝑛,𝑘}=𝐇_{1∶𝑛,𝑘}/𝐑_𝑘,𝑘

(4)  for  𝑗=𝑘+1∶𝑛

(5)   𝐑_𝑘,𝑗=𝐐^𝐻_{1∶𝑛,𝑘}𝐇_{1∶𝑛,𝑗}

(6)   𝐇_{1∶𝑛,𝑗}=𝐇_{1∶𝑛,𝑗}−𝐐_{1∶𝑛,𝑘}𝐑_𝑘,𝑗

(7)  end

(8) end