Patent ID: 8023579
Filing Date: 2011-09-20
Classification: H03D,H04L

Abstract:
1. A quadrature modulation device comprising: a quadrature detector which performs quadrature detection on a reception signal obtained by receiving a radio wave from a radio frequency identification tag, to generate an in-phase signal and a quadrature-phase signal; demodulation means for detecting a preamble of a particular transition pattern in at least one of the in-phase signal and the quadrature-phase signal, decoding the at least one of the in-phase signal and the quadrature-phase signal to obtain data succeeding the preamble, and performing error detection on a decoding result to check for errors; and wherein the demodulation means is configured to save a predetermined one of the decoding results for the in-phase signal and the quadrature-phase signal when it is confirmed that the absence of errors is detected in both decoding results.