| 摘要 |
<p>Methods and apparatus for spectrum sensing for the presence of ATSC digital television signals and NTSC analog television signals in the VHF/UHF TV bands are provided. Similar time-domain signal structures for the ATSC and NTSC signals are used to perform spectrum sensing. For ATSC digital television signals, a Segment-Sync based spectrum sensing method is provided, based upon the correlation of Segment Sync symbols inserted in the beginning of each data segment. Additionally, a general adjacent channel interference alleviation scheme by using a narrower receiver filter is also provided. For NTSC analog TV signals, a horizontal-sync based spectrum sensing method is provided which is based upon the correlation of horizontal sync signals present at the beginning of each line of an NTSC analog TV signal. The proposed spectrum sensors can reliably detect the target signals when a strong adjacent channel interference exists and the signal power is as low as dBm as set in FCC test models.</p> |
