MATLAB: Can you do this calculation any faster

optimizationrepmatreshapespeed

Hi there
I am trying to optimize some code, an example is given below. In my code, v_ustar etc are calculated elsewhere, and depend on q. This piece of code needs to run in a quite large loop (larger than the 1:1000 given as example here), and I don't think vectorization of the entire loops is possible due to RAM issues. N is typically 16, but can be larger as well.
I use Ubuntu and MATLAB R2014a (I will probably upgrade to R2014b soon)
N=16;for q=1:1000%generate some random test datav_ustar=rand(2*N,N,N);vstar_u=rand(2*N,N,N);u_ustar=rand(2*N,N,N);vstar_v=rand(2*N,N,N);F=... repmat(reshape(v_ustar,[2*N 1 N N]),[1 2*N 1 1]).*...repmat(reshape(conj(vstar_u), [1 2*N N N]),[2*N 1 1 1])-...repmat(reshape(u_ustar,[2*N 1 N N]),[1 2*N 1 1]).*...repmat(reshape(conj(vstar_v), [1 2*N N N]),[2*N 1 1 1]);F=reshape(F,4*N^2,[]).';end
[2*N 1 N N]