| 摘要 |
<p>Multi-channel wireless TV receiving apparatus includes a first down-converter for converting a first signal having a first frequency bandwidth into a second signal having a second frequency bandwidth, a second down-converter for converting the second signal into a third signal having a third frequency bandwidth, a demodulator for extracting from the third signal a control data signal to be used in controlling the receiving apparatus, a memory for storing variables used in controlling the receiving apparatus and a controller for shifting a reference frequency of the first down-converter by a predetermined frequency based on the control data. The control data may include an identification number for a subscriber of the receiving apparatus, which is to be compared with an identification number stored in the memory. By shifting the reference frequency and verifying the identification number, the receiving apparatus can prevent an unauthorized person from watching TV programs.</p> |
