POLARITY DECISION PHASE DETECTOR CIRCUIT FOR HIGH ORDER QUADRATURE MODULATION AND METHOD THEREOF

摘要

PURPOSE: A polarity decision phase detector circuit for a high order quadrature modulation(QAM) and a method thereof are provided, which detects frequencies in a wider band without a subsidiary circuit. CONSTITUTION: A multiplier(20) outputs a compensation signal(q(n)) by multiplying a received QAM signal by an output signal(v(n)) from a voltage controlled oscillator(VCO)(70). A power detector(30) detects a signal having a high SNR characteristics among the compensation signal applied from the multiplier. Polarity decision units(30,40) decide polarities of I and Q channel respectively by inputting an output signal from the polarity decision units. A phase detector(50) detects a phase error by inputting an output signal(p(n)) of the polarity decision units and the output signal(q(n)) of the multiplier. A loop filter(60) filters the phase error detected through the phase detector and provides it to the VCO. And a symbol determination unit(80) generates decision data by determining a symbol by inputting the compensation signal being output from the multiplier.