I had a kind of similar problem with some discreat data so what I did was use linspace function to create some equally spaced data in between the collected data to create more resolution. The problem being these are manually increased resolution. Theoretically speaking you can't get higher resolution if you don't have the data. So you have to make some. I am giving my algorithm may be you can take a similar approach to generate your code.
d1=rand(50,1); % your data
d2=zeros(500,1); % generated higher resolution data
for i=0:length(d1)-2
d2(i*10+1:((i*10)+10)) = linspace(d1(i+1),d1(i+2),10);
end
d2(491:500)=linspace(d1(end),d1(end),10);
May be you can have an idea how to do yours from this.
