A signal processing method in a signal processing apparatus of a mobile terminal comprising a radio-frequency front end, a radio-frequency interference canceller, an analog-to-digital converter and a digital interference canceller, comprising: receiving a downlink signal that carries interference of an uplink signal; estimating a self-interference signal to generate an estimated self-interference signal by using an uplink signal received on an analog input interface of the radio frequency interference canceller; and, performing, at the radio-frequency interference canceller, first interference cancellation on the interference of the uplink signal by using the estimated self-interference signal such that a frequency corresponding to the uplink signal is close to the estimated frequency corresponding to the estimated self-interference signal, a remaining amount of interference of the uplink signal is less than a first interference threshold and such that a duplexer is not required on the radiofrequency front-end, wherein the method further comprises: setting the first interference threshold to a value which is less than a saturation value of the analog-to-digital converter, wherein after the performing first interference cancellation on the uplink signal by using an estimated self-interference signal and after the analog-to-digital converter, the method further comprises at the digital interference canceller: performing, by using an estimated remaining self-interference signal, second interference cancellation on the remaining amount of interference of the uplink signal that is obtained after the first interference cancellation, so that a remaining amount of interference of the uplink signal is less than a second interference threshold. receiving a downlink signal that carries interference of an uplink signal; estimating a self-interference signal to generate an estimated self-interference signal by using an uplink signal received on an analog input interface of the radio frequency interference canceller; and, performing, at the radio-frequency interference canceller, first interference cancellation on the interference of the uplink signal by using the estimated self-interference signal such that a frequency corresponding to the uplink signal is close to the estimated frequency corresponding to the estimated self-interference signal, a remaining amount of interference of the uplink signal is less than a first interference threshold and such that a duplexer is not required on the radiofrequency front-end, wherein the method further comprises: setting the first interference threshold to a value which is less than a saturation value of the analog-to-digital converter, wherein after the performing first interference cancellation on the uplink signal by using an estimated self-interference signal and after the analog-to-digital converter, the method further comprises at the digital interference canceller: performing, by using an estimated remaining self-interference signal, second interference cancellation on the remaining amount of interference of the uplink signal that is obtained after the first interference cancellation, so that a remaining amount of interference of the uplink signal is less than a second interference threshold. setting the first interference threshold to a value which is less than a saturation value of the analog-to-digital converter, wherein after the performing first interference cancellation on the uplink signal by using an estimated self-interference signal and after the analog-to-digital converter, the method further comprises at the digital interference canceller: performing, by using an estimated remaining self-interference signal, second interference cancellation on the remaining amount of interference of the uplink signal that is obtained after the first interference cancellation, so that a remaining amount of interference of the uplink signal is less than a second interference threshold.