Patent ID: 7729449

Claim:
A digital signal processing and receiving apparatus comprising: a receiving antenna; an A/D converter that converts analog reception signals received by said receiving antenna into digital signals; and a digital signal processing part that outputs a code signal according to a modulation signal corresponding to a code to be received by said receiving antenna by separating the code signal from the digital signals acquired as a result of digital conversion by said A/D converter by removing from the reception signals a frequency component having an amount of change that is smaller than a threshold value for a maximum continuation period during which the code can be maintained, wherein the threshold value is a minimum spectrum change needed to detect a clock noise multiplication generated continuously at a same level, wherein said digital signal processing part has noise eliminating means for eliminating a signal as a noise having a frequency fluctuation or an output intensity fluctuation exceeding a predetermined rate or a predetermined value from signals acquired as a result of digital conversion by said A/D converter.