I tried combining several inverters, one summation op amp and one op amp for integration. However, LT-spice produced rubbish at the output, and was really having a tough time doing ac analysis on this big circuit. The circuit I am talking about is this one:
Few of my colleagues briefly mentioned that this can be done using only two op-amps, but I cant't seem to find that solution. All suggestions will be appreciated. And I am sorry for posting the circuit drawn on paper, but it was easier for me that way to sketch the (presumed) output signals of each stage.