In a digital terrestrial broadcasting system that adopts OFDM (orthogonal frequency division multiplexing) method, echoes (multipath waves) outside the guard interval can distort the received signal and cause extreme degradation of the signal quality. Though DOA (direction of arrival) of an echo of high received level can estimate by rotating a receiving antenna, it is difficult to estimate DOA of multiple echoes of low received level especially outside the guard interval. Therefore, we have developed a DOA measurement method that uses a pair of receiving antennas without rotating. This method can even measure a delay profile of echoes outside the guard interval. Field experiments verified the performance of the method.
