Can some can explain the difference between Resource Element Groups (REG) and PHICH Groups?
I'm still confused with the statement that says, "A total of 8 orthogonal sequences have been defined, so each PHICH group can carry up to 8 PHICHs."
What is the duration of a sub-frame and a frame in LTE? How many OFDM symbols per sub-frame? What is the transmit time interval (TTI) over which an allocation happens in the DL or UL?
