Patent ID: 7519107

Claim:
A CDMA receiving apparatus which receives radio-signal of CDMA scheme to perform a channel detection and channel demodulation operations, wherein said apparatus comprises: a received signal wave-form buffer unit which digitalizes the amplitude of the wave-form of the signal which is received by a radio unit for recording the signal as data on the received signal wave-form; a delay profile generating unit for generating a delay profile which represent the distribution of signal power value relative to delay time on a path by calculating as a signal power value a sum of correlation values which are obtained by multiplying said received signal wave-form data by a desired channel code over a time interval which is provided as a predetermined desired length of constraint if the time length of said received signal wave-form data recorded on said received signal wave-form buffer unit becomes a predetermined processing unit length; a path search unit for obtaining the time of respective demodulation paths by detecting the time at which the signal power value of said delay profile peak to detect path candidates used for demodulating said received signal and to select the demodulation paths which are to be applied for demodulation, having a number not more than predetermined maximum number of paths; a channel estimating unit for demodulating pilot symbols of respective demodulation paths by determining the correlation between said received signal wave-form data recorded on the received signal wave-form buffer unit and demodulation code assigned to said CDMA receiving apparatus on a symbol unit basis at said time of said respective demodulation paths which are selected by said path search unit and for estimating an adjustment angle for aligning phases of said respective demodulation paths from a result of demodulation of said pilot symbols; a channel demodulating unit which determines correlations between said received signal wave-form data recorded on said receiving signal wave-form buffer unit and said demodulation code at said time of said respective selected demodulation paths, as demodulation symbols on a symbol unit basis and for adjusting the phases of the symbols which are determined for each demodulation path based upon said adjustment angle of said each demodulation path which is estimated by said channel estimating unit; a RAKE unit which combines said demodulation symbols of said respective demodulation paths, the phases of which are aligned to obtain combined demodulation symbols for outputting them; and a reception quality measuring unit for measuring the reception quality by comparing said combined demodulation symbols related with said pilot symbols of said combined demodulation symbols with a predetermined pilot pattern, and in that said demodulation paths which are selected in said path search unit are changed depending upon whether or not said reception quality measured by said reception quality measuring unit is lower than a predetermined preset reference value.