Patent ID: 7283599

Claim:
A phase error detector for generating a phase correction signal to correct a phase difference between a reference frequency of a voltage-controlled oscillator and a carrier frequency of a received signal which is received by a quadrature-amplitude modulated (QAM) receiver, the phase correction signal having a zero-crossing locking point, the received signal having in-phase components and quadrature components in a plurality of decision regions, the phase error detector comprising a signal receiver, a signal generator, and a processor for processing a plurality of different algorithms; and the phase error detector being operative for successively executing the algorithms in an order, for each of the plurality of decision regions, until the phase correction signal having no additional zero-crossing locking points is generated, wherein the plurality of different algorithms being stored in the phase error detector, and being arranged in the order as below: S 1 =FQ f ( ZI )− FI f ( ZO ) S 2=±2 FO f ( ZI ) S 3=±2 FI f ( ZO ) S 4=±2 ZI ZO S 5=0 in which S 1 , S 2 , S 3 , S 4 , S 5 are different phase correction signals, in which ZI and ZO are the in-phase and quadrature components of the received signal, in which FI and FO are offsets of ZI and ZQ, in which f(ZI)=ZI or sign (ZI), and f(ZO)=ZO or sign (ZO).