| 摘要 |
A complex base band signal b of a send signal from a mobile station of the CDMA system is obtained, then a portion of the complex base band signal is normalized in amplitude, and the normalized signal is synchronized with a PN code and the time reference is estimated. A frequency error is estimated from a complex correlation value used for the estimation of the time reference. The normalized signal is corrected corresponding to the estimated frequency error, and the corrected signal is used to estimate and correct the initial phase. The corrected signal and the time reference are used to estimate a time lag between a symbol point and the sample point nearest thereto and a reference signal displaced by the time lag is generated. The reference signal and the corrected signal are used to estimate the remaining frequency error and initial phase by the least squares method. All the estimated values are used to correct the signal b, and the corrected signal and the reference signal are used to calculate the waveform quality. |
