How can I solve this problem?( {real constant} <= {convex})

The paper :

Part of My code :

for n = 1: N+1
d_min^2 <= norm(qsr(n,: ) - qe(n,: ),2)^2 + 2 * norm(qsr(n,: ) - qe(n,:),2) * norm(qs(n,: ) - qsr(n,: ),2)

In this,the qs is a variable,is a N+1 * 2 marix which should store n+1 coordinates.others are constants.
The error:
Disciplined convex programming error:
Invalid constraint: {real constant} <= {convex}
error <= (line 21)
b = newcnstr( evalin( ‘caller’, ‘cvx_problem’, ‘[]’ ), x, y, ‘<=’ );

The constraint you showed is not convex, so CVX rejected it. Even when it is convex, it needs to be written down in DCP rule so that CVX can accept it. See Why isn't CVX accepting my model? READ THIS FIRST!

Maybe this paper has some questions, thank you for your answer!