| 摘要 |
PROBLEM TO BE SOLVED: To obtain plural methods and devices for digitally detecting the slope in a baseband. SOLUTION: This slope detector is driven with a baseband, in order to detect the slope of a baseband signal spectrum in a digital radio system allowed to be driven the basebad and having orthogonal amplitude modulation (QAM) and mutually compares the signal output power levels of upper and lower side bands of a received passband signal. The slope detector has transversal filters 24, 26 for respectively filtering the input of I and Q channels and two multipliers 16 and a coupler 18 for processing the outputs of these filters 24, 26 and supplies an output indicating the slope of a passband signal spectrum. The output is a value converted into an instantaneous slope and has three states indicating a positive slope, a zero slope or a negative slope. |
