Problem 6(5+5+5+5pts). Answer the following questions on digital modulation techniques: 1. What is the name of the electronic device that performs modulation in your home and sits in between your router and your cable Internet port? 2. In a constellation diagram, all points lie on the horizontal axis. What kind of modulation is being used? 3. Can a station using QAM-16 send 3 bits per symbol? Explain why (not). 4. Twelve signals, each requiring 4,000Hz, are multiplexed onto a single channel using FDM. What is the minimum bandwidth required for the multiplexed channel? Assume that the guard bands are 400Hz wide