A technique for automatically detecting the constellation size of a quadrature amplitude modulated (QAM) signal

摘要: A technique for determining the constellation size of a QAM signal received by receiver. In general, implementation my has, as an input signal, having one plurality sizes and determines size, e.g., 4, 16, 32-ary, analyzing probability density function (pdf) over pre-established time period. To properly analyze is first squared then normalized to preset value, 2.0. As such, power in any various constellations fixed level. By generating histogram number levels modulation contained signal. Each has unique thus forms histogram. From histogram, particular can be determined. Thus, without requiring priori carrier lock before accomplishing such determination.