I want to solve a simple convex problem that minimizes the power of transmitting devices. I have a supposed that there are 10 devices each communicating with another device. But, when I run the program it gives me this error:

Error using .* (line 173)

Disciplined convex programming error:

Cannot perform the operation: {concave} ./ {real affine}

Error in ./ (line 19)

z = times( x, y, ‘./’ );

Error in testcode4 (line 36)

Rate(i,j) = W*(log(1+(p(i)((distance(i,j)).^(-pathloss)))./log(2))./((NSDW)+I_D(i,j)));

How can I convert the denominator term in the Rate expression, so that the Rate expression can be solved?

```
distance = rand(10,10);
Rate_min = ones(10,10);
Power_total = 10;
W = 1;
NSD = 1;
pathloss = 1;
cvx_begin
variable p(10,1) nonnegative
minimize norm(p)
subject to
for i = 1:10
for j = 1:10
I_D(i,j) = (p(j))*((distance(i,j)).^(-pathloss));
Rate(i,j) = W*(log(1+(p(i)*((distance(i,j)).^(-pathloss)))./log(2))./((NSD*W)+I_D(i,j)));
end
end
sum(p) <= Power_total;
cvx_end
```