A method for receiving a downlink data block of a packet data service, comprising: receiving an aggregated modulated signal, wherein the aggregated modulated signal comprises a first modulated signal and a second modulated signal; detecting and obtaining a first symbol rate and a first modulation mode of the first modulated signal, and demodulating the first modulated signal according to the first modulation mode and the first symbol rate to obtain first information, wherein the first information corresponds to time domain signals; detecting and obtaining a second symbol rate and a second modulation mode of the second modulated signal, and demodulating the second modulated signal according to the second modulation mode and the second symbol rate to obtain second information, wherein demodulating the second modulated signal further comprises performing a Fourier transform to transform the second modulated signal into a frequency domain signal; and decoding the first information and the second information to obtain the downlink data block; the method being characterized by: the detecting and obtaining a second symbol rate and a second modulation mode of the second modulated signal, and demodulating the second modulated signal according to the second modulation mode and the second symbol rate to obtain second information is specifically: demodulating the second modulated signal by using a symbol rate and a corresponding demodulation mode to obtain a first predicted value of the second information; demodulating the second modulated signal by using another symbol rate and a corresponding demodulation mode to obtain a second predicted value of the second information; obtaining a first evaluation metric value according to the first predicted value, a first frequency domain signal, and a first frequency domain channel factor; and obtaining a second evaluation metric value according to the second predicted value, another frequency domain signal, and another frequency domain channel factor; and comparing the first evaluation metric value and the second evaluation metric value to obtain as an evaluation metric value one of the first or second evaluation metric values, wherein a predicted value corresponding to the obtained evaluation metric value is the second information. receiving an aggregated modulated signal, wherein the aggregated modulated signal comprises a first modulated signal and a second modulated signal; detecting and obtaining a first symbol rate and a first modulation mode of the first modulated signal, and demodulating the first modulated signal according to the first modulation mode and the first symbol rate to obtain first information, wherein the first information corresponds to time domain signals; detecting and obtaining a second symbol rate and a second modulation mode of the second modulated signal, and demodulating the second modulated signal according to the second modulation mode and the second symbol rate to obtain second information, wherein demodulating the second modulated signal further comprises performing a Fourier transform to transform the second modulated signal into a frequency domain signal; and decoding the first information and the second information to obtain the downlink data block; the method being characterized by: the detecting and obtaining a second symbol rate and a second modulation mode of the second modulated signal, and demodulating the second modulated signal according to the second modulation mode and the second symbol rate to obtain second information is specifically: demodulating the second modulated signal by using a symbol rate and a corresponding demodulation mode to obtain a first predicted value of the second information; demodulating the second modulated signal by using another symbol rate and a corresponding demodulation mode to obtain a second predicted value of the second information; obtaining a first evaluation metric value according to the first predicted value, a first frequency domain signal, and a first frequency domain channel factor; and obtaining a second evaluation metric value according to the second predicted value, another frequency domain signal, and another frequency domain channel factor; and comparing the first evaluation metric value and the second evaluation metric value to obtain as an evaluation metric value one of the first or second evaluation metric values, wherein a predicted value corresponding to the obtained evaluation metric value is the second information. demodulating the second modulated signal by using a symbol rate and a corresponding demodulation mode to obtain a first predicted value of the second information; demodulating the second modulated signal by using another symbol rate and a corresponding demodulation mode to obtain a second predicted value of the second information; obtaining a first evaluation metric value according to the first predicted value, a first frequency domain signal, and a first frequency domain channel factor; and obtaining a second evaluation metric value according to the second predicted value, another frequency domain signal, and another frequency domain channel factor; and comparing the first evaluation metric value and the second evaluation metric value to obtain as an evaluation metric value one of the first or second evaluation metric values, wherein a predicted value corresponding to the obtained evaluation metric value is the second information.