Digital receiver

A digital receiver comprising:

• a noise attenuation and signal magnitude mapping variable amplifying unit including a filter and a variable amplifier, the noise attenuation and signal magnitude mapping variable amplifying unit for dividing a power of an analog signal into a plurality of sections, controlling a gain by the section to adjust a magnitude of the analog signal, and attenuating white noise and an interference signal in the analog signal;
• an analog-to-digital converter (ADC) for performing subsampling on a carrier frequency of a desired signal and performing oversampling on a band of the desired signal by using a sampling frequency to convert the analog signal which has passed through the noise attenuation and signal magnitude mapping variable amplifying unit into a digital signal of a direct conversion (DC) frequency band or an intermediate frequency band, the ADC having a dynamic range for processing the desired signal and for processing an undesired signal adjacent to the desired signal by using the oversampling when converting the analog signal into the digital signal;
• and
• a digital signal processing unit for converting a signal frequency of the digital signal or digital-filtering the undesired signal in the digital signal, and processing the digital signal by digitally adjusting a gain,
• wherein the ADC comprises an I-path subsampling ADC and a Q-path sub sampling ADC,
• the I-path subsampling ADC converts the analog signal into an I signal by using the sampling frequency according to a first clock signal, and
• the Q-path subsampling ADC converts the analog signal into a Q signal by using the sampling frequency according to a second clock signal, the first clock signal and the second clock signal being mutually orthogonal.