Algorithm 1: Calculation of Central and Edge Users

Step 1: Ensure that the pilots in the pilot sequence set $\mathsf{\varsigma }$ are orthogonal to each other.

Step 2: Calculate the central user ${\mathrm{K}}_{\mathrm{c}}$ and the edge user ${\mathrm{K}}_{\mathrm{e}}$ according to Equations (10) and (11).

Step 3: The central user randomly allocates pilots in the pilot set ${\mathrm{P}}_{\mathrm{c}}.$

Step 4: The edge users in adjoining cells are correspondingly assigned a pilot sequence set ${\mathrm{P}}_{\mathrm{e}1},{\mathrm{P}}_{\mathrm{e}2},{\mathrm{P}}_{\mathrm{e}3}$.