I am trying to calibrate my forecast and discount curves using the multi-curve approach with OIS discounting. To do so, I have a implemented multivariate Newton-Raphson root finder. I am finding a bit troublesome writing down the necessary equations in order to have a number of unknowns equal to the number of functions to solve, so I must be missing something.
For example, when calibrating my Libor and OIS curves together at the same time, my first equation for a 1Y swap instrument that receives fix annually - pays float semi-annually would be:
$$ DF(1Y)\,\tau_1\,FixedRate(1Y) - DF(6M)\, \delta_1 \,Fwd^{6M}_{0.5Y} - DF(1Y)\, \delta_2 \,Fwd^{6M}_{1Y} = 0 $$
Here, $\tau$ and $\delta$ are the corresponding time fractions and $DF$ refers to ois discount factors.
Only with this first equation, I already have three unknowns: $DF(6M), DF(1Y)$ and $Fwd^{6M}_{1Y}$. Adding equations for swaps of higher maturities only adds new unknowns, and this is even without adding other equations I need such as those of 3M-6M tenor swaps, Libor-OIS basis swaps, etc etc.
What is it that I am missing here?