Why can't CVX do the prod?


(yn) #1
 cvx_clear
    cvx_begin 
        variables X(N,1) Y(N,D) 
        expressions V(N,1) U(N,1) T(D,1) W(D,1)  M(N,D) Z(N,D) A(D,1)  Q(D,1)  S(D,1)        
    
      for n=1:N
            
        U(n,1) = X(n,1):

         V(n,1) = 1; 
            for i=1:D
             A(i)=1;
             Q(i)=1;
             
               
                 V(n,1) = V(n,1) + Y(n,i)*H_d(n,1,i); 
                 
            end

        V(n,1) = Rmin(n,1)*V(n,1)-X(n,1)*H_c(1,n);   
        
      end

      for  i=1:D
          for n=1:N
               for j=1:D
                
                M(n,i) = M(n,i) +Y(n,j)*H_d(n,i+1,j)+1;
               end
             Z(n,i) =M(n,i)-Y(n,i)*H_d(n,i+1,i);
          end
      end
      for  i=1:D  
      for n=1:N
         A(i,1)=A(i,1)*Z(n,i);
         Q(i,1)=Q(i,1)*M(n,i);
      end
      T(i,1)=Rreq*A(i,1)-Q(i,1);
    end
  W(:,1) = X(1,1);
    for d=1:D
          for i=((d-1)*N+1):d*N
                               
                W(d,1) = W(d,1) + Y(i,1); % sum power consumption of the D2D transmitter d
          end
          
    end
 
    W(:,1) = W(:,1) - X(1,1);
    
 minimize (sum(X)+sum(Y))
    subject to
        V <=  0;
        U <=  Pn_max;
        W <= Pd_max; 
         T <= 0;
         X >= 0;
         Y >= 0;
cvx_end

I just wanna todo the prod(M) and prod(Z),but can not find a way ! help! please


(Mark L. Stone) #2

Why do you believe prod(M) and prod(Z) are convex? Therefore, why do you believe they can be expressed in CVX?