From the Top Down: The Physical Layer—AM OFDM

Continuing our trip down the IBOC protocol stack, this time on the AM IBOC signal, it took the better part of two chapters to drill into Layer1. Chapter 5 covered the thin Layer 2 and burrowed into the upper-level processes of Layer 1—scrambling, channel encoding, and interleaving. Chapter 6 continued the journey, pursuing logical connection to the OFDM IBOC signal. The Logical Channels were linked to the IBOC signal structure, with symbols, blocks and frames in the time domain, and interleaver matrices assigned to OFDM subcarrier groups in the frequency domain. What remain to be discussed about the AM IBOC Layer 1 document (NRSC-5 Reference Document 2) are its electrical characteristics