RADIO EQUIPMENT USING MULTIPLE-VALUED QAM AND THRESHOLD ESTIMATION METHOD

摘要

PPROBLEM TO BE SOLVED: To provide a method and equipment by which data is demodulated by estimating a threshold even when no amplitude information is clearly provided to a reception side from a transmission side in receiving a multiple-valued QAM signal and synchronizing the amplitude. PSOLUTION: The FV (Fading Vector) estimation section 203 of a demodulation section 117 outputs a noise ratio-reduced FV signal by receiving a CPICH (Common Pilot Channel) diffusion demodulation signal. A phase synchronization section 204 supplies a PDSCHI (Physical Down-link Shared Channel) recovering phase shift by applying FV signal complex conjugate to a PDSCH diffusion demodulation signal and a Q signal to a multiple-valued QAM amplitude synchronization detection section and an amplitude demodulation section. A first quadrant conversion section 210 attracts the signals of the second to fourth quadrants of the phase-synchronized PDSCHI and a PDSCHQ signal to the first quadrant. A threshold detection section 211 calculates the threshold of multiple-valued QAM from the first quadrant signal and the FV signal for sending to an amplitude demodulation section 205. The amplitude demodulation section conducts amplitude demodulation to output a multiple-valued QAM demodulated signal. The threshold detection section 211 makes assumptions about the value of the reception data, increases the accuracy of an assumed values by using the data to estimate the threshold by using the frequency and errors of each level from the assumed thresholds. PCOPYRIGHT: (C)2004,JPO&NCIPI