| 摘要 |
PURPOSE: A method for automatically compensating linearity in a digital television broadcasting system is provided to more accurately compensate linearity and non-linearity of a system far-end signal after compensating a linear error of a priority linear compensating receiver. CONSTITUTION: If ISA(Industry Standard Architecture) bus input I and Q digital input signals are inputted, it is judged whether an automatic alarm signal is generated(611). If so, a digital potentiometer step is adjusted(612). A reference signal is generated(613). An SNR(Signal-to-Noise Ratio) or an EVM(Error Vector Magnitude) is operated(614). It is judged whether the SNR or the EVM satisfies an ATSC standard(615). If so, it is judged whether the SNR or the EVM is executed five times(616). If so, the SNR or the EVM satisfies the ATSC standard five times(617). If not, the five-time count is set as '0'(619). If so, the automatic alarm signal is stopped and a coefficient generating signal is transmitted to linearity compensation software(618). If the SNR or the EVM does not satisfy the ATSC standard, a digital potentiometer step sweep algorithm is executed(620). The automatic alarm signal is generated and transmitted to linearity compensation software(621).
|
