This application discloses a communications chip structure, including: a channel selection module, configured to receive an input signal, where the input signal is a signal of a preset narrow bandwidth span or a signal of a preset wide bandwidth span; and a digital baseband module, configured to control the channel selection module to select a first sampling and quantification channel when the input signal is a signal of the preset narrow bandwidth span, or control the channel selection module to select a second sampling and quantification channel when the input signal is a signal of the preset wide bandwidth span. The channel selection module is further configured to send the input signal to the first sampling and quantification channel or the second sampling and quantification channel for sampling and quantification.