I have a spot curve where the front-end points (1Y, 2Y) have a fixed/float frequency of 3M3M, while the rest of the points are 6M6M. I want to build a full 6M6M curve. My question is: How can I derive 6M6M IRS prices from the 3M3M prices for the 1Y and 2Y tenors, given that I don't have basis swap prices?
Any insights, formulas, or references to relevant literature would be greatly appreciated. Thank you!