APPARATUS AND METHOD FOR PILOT INSERTION AND ARRANGEMENT FOR HIERARCHICAL MODULATION IN OFDM TRANSMISSION SYSTEM

摘要

A hierarchical modulation apparatus for improving a transmission performance of an OFDM transmission system using the insertion and the specific arrangement pattern of a pilot, and a method thereof are provided to improve a receiving performance by additionally transmitting a pilot signal to an enhancement layer signal. A hierarchical modulation apparatus for improving a transmission performance of an OFDM transmission system using the insertion and the specific arrangement pattern of a pilot includes a first channel coding unit(200), a second channel coding unit(210), a pilot insertion unit(220), and a layer modulation unit(240). The first channel coding unit encodes a base layer signal column. The second channel coding unit encodes an enhancement signal column. The pilot insertion unit inserts a pilot into the enhancement signal column. The pilot has the correlation with the base layer signal column corresponding to the same sub carrier with the enhancement layer signal column which is encoded in the second channel coding unit. The layer modulation unit modulates and combines each of the signal columns outputted from the first channel coding unit and the pilot insertion unit.