i am trying to run the below cvx code and when increase the value of K greater than 8, cvx_status turns to infeasible. can anyone please help?
clear all;
clc;
N = 6; % Number of antennas
K = 8; % Number of users
H = randn(N, K) + irandn(N, K); % random channel matrix
sigma2 = 0.5ones(K,1); % noise power vector
gamma = 2*ones(K,1); % minimum SINR requirement vector
cvx_begin sdp quiet
variable W(N, K) complex;
expression S(K,1)
for k = 1:K
S(k) = (ctranspose(W(:,k))*H(:, k))/sqrt(gamma(k));
end
expression I(K, K);
for k = 1:K
for m = 1:K
if( k == m)
I(k, k) = sqrt(sigma2(k));
else
I(k, m) = ctranspose(W(:, k))*H(:,m);
end
end
end
expression obj;
for k = 1:K
obj = obj + sum_square_abs(W(:,k));
end
minimize obj;
subject to
subject to
for k = 1:K
imag(S(k)) == 0;
real(S(k)) >= 0;
[real(S(k))*eye(K), I(:, k); (I(:, k))’, real(S(k))] >= 0;
end
cvx_end