You are not specific regarding the type of "implementation " you mean here - Make own implementation in Micorcontroller Part of SoC; Make own implementation in PL Part or FPGA
1. Signal gen can also be done using look-up tables. Depending on the nature of signal to be generated, the "look-up" table method is supposed to be efficient. The savings in processing time can be significant, because retrieving a value from memory (where loop-up table values are stored) is often faster than carrying out an "expensive" computation or input/output operation.
2. That is your homework, search out and compare!