Firstly , the theory basis of if digital receiver is introduced , which includes over - sampling digital mixing receiving scheme and mathematic model with which the scheme is proved correctly . secondly , the numerically controlled oscillator ( nco ) is designed and realized 首先介紹了中頻數(shù)字接收機采用的過采樣數(shù)字混頻數(shù)字接收方案,然后給出數(shù)學模型,從理論上論證了該方案的可行性;二、數(shù)控振蕩器設計與實現(xiàn)。