CDMA DEMODULATION CIRCUIT AND DEMODULATING METHOD

摘要

A CDMA demodulation circuit which can reduce interference wave components from another user in the cell and can follow up high-speed fading. The frequency band of the received inputted spread-spectrum signals are compressed back by means of an orthogonalizing filter (103). The filter (103) successively gives a delay of 1/m of the chip period of the spread codes to the inputted spread-spectrum signals and outputs compressed-back signals by multiplying the inputted spread-spectrum signals by a tap factor and summing up the multiplied results. An absolute phase estimating and phase error compensating section (107) compares the pilot symbols in the compressed-back signals with the pilot symbols of a known pattern and finds the phase shifts of the received pilot symbols. The section (107) compensates the phase of each information symbol by interpolating the phase shifts in the respective information symbols. An identifying and judging section (108) identifies the phase-compensated information symbols. A tap factor control section (110) calculates the tap factor so that the mean square error of the errors of signals before and after the identification may be the minimum and feeds back the calculated tap factor to the filter (103).