| 摘要 |
PURPOSE: An apparatus for normalizing an input terminal of a channel decoder in a code division multiple access(CDMA) mobile communication system is provided to divide each receiving demodulation symbol value into demodulation symbol sizes having no noises and to multiply the divided symbol values by a normalization reference level value, by normalizing the demodulation symbol values to make the demodulation symbol sizes exactly mapped to the normalization reference level value, so that the channel decoder can have a high channel decoding capacity. CONSTITUTION: A demodulation symbol least square average block(310) squares each demodulated symbol value to find an average dispersion value. A noise measurer(320) finds a difference between demodulation symbol values obtained by being accumulated as the length of an orthogonal spreading code and demodulation symbol values obtained by being accumulated as the length of a next orthogonal spreading code, and squares the symbol values. The demodulation symbol values are from pilots or synchronous channels outputted from a first symbol demodulator to a N symbol demodulator. The noise measurer has averages of the squared values corresponding to each signal path during a corresponding section, and adds average values of the signal paths to the squared values to find a noise dispersion value. An arithmetic operator(350) subtracts the noise dispersion value of the section from dispersions of the demodulated symbol values. A least square root block(330) performs a least square root process to an output of the operator to find a size of a received demodulating symbol in a receiving terminal, if a noise is not added. A normalizer(340) divides each demodulation symbol value by a size of the received demodulating symbol, and multiplies the symbol values by a normalization reference level value. The normalizer outputs a normalization demodulating symbol mapping a multiplied result into a quantization level. |
