| 摘要 |
Method and apparatus for use with digital television receivers are included among the embodiments. In exemplary systems, components of an interfering analog television signal (e.g., an NTSC signal) in the same channel as a DTV signal are separately estimated and canceled from the DTV signal. For instance, separate frequency shifters produce shifted versions of the DTV signal, each shifter placing one interfering NTSC carrier signal at or near DC. A DC detector detects the NTSC carrier strength for each carrier, and carrier cancellation signals are synthesized based on these measured carrier strengths. This rejection filter is simpler than prior art filters that require phase-lock on the interfering carriers, and also allows the filter to operate when phase-lock on interfering carriers is difficult to obtain. Other embodiments are described and claimed. |
