Turbo codes
a. Why are turbo codes said to belong to the family of convolutional codes?
b. Briefly describe the main components of a turbo code. Why are the individual encoders called RSC?
c. The convolutional encoder of Figure 7.10(b) is nonrecursive. Make the modifications needed to make it usable in a turbo code.
d. As we saw, turbo codes are quite new (1993). Even though they could outperform all codes in use at that time, why were they overshadowed only a few years later?