1. A communications apparatus for a Time Division Duplexing Long Term Evolution, TDD LTE, system, comprising: a processing module, configured to determine a frame structure of a serving cell, wherein in the determined frame structure of the serving cell, one radio frame comprises at least one first subframe, and the first subframe comprises the following four parts in a consecutive order: a first part comprising a symbol used for downlink transmission; a second part: a guard period; and a third part comprising a symbol used for uplink control information transmission and/or sounding reference signal SRS transmission; and a fourth part comprising a symbol that is dynamically or half-statically configured to be used for downlink transmission or for uplink data transmission, wherein a quantity of symbols comprised in the first part is one, a length of the guard period is one symbol, a quantity of symbols comprised in the third part is one, and a quantity of symbols comprised in the fourth part is eleven; or the first part comprises seven symbols, a length of the guard period is one symbol, the third part comprises one symbol, and the fourth part comprises five symbols; or the first part comprises eight symbols, a length of the guard period is one symbol, the third part comprises one symbol, and the fourth part comprises four symbols; and a transceiver module, configured to send and receive information in the serving cell according to the frame structure, determined by the processing module, of the serving cell. a processing module, configured to determine a frame structure of a serving cell, wherein in the determined frame structure of the serving cell, one radio frame comprises at least one first subframe, and the first subframe comprises the following four parts in a consecutive order: a first part comprising a symbol used for downlink transmission; a second part: a guard period; and a third part comprising a symbol used for uplink control information transmission and/or sounding reference signal SRS transmission; and a fourth part comprising a symbol that is dynamically or half-statically configured to be used for downlink transmission or for uplink data transmission, wherein a quantity of symbols comprised in the first part is one, a length of the guard period is one symbol, a quantity of symbols comprised in the third part is one, and a quantity of symbols comprised in the fourth part is eleven; or the first part comprises seven symbols, a length of the guard period is one symbol, the third part comprises one symbol, and the fourth part comprises five symbols; or the first part comprises eight symbols, a length of the guard period is one symbol, the third part comprises one symbol, and the fourth part comprises four symbols; and a transceiver module, configured to send and receive information in the serving cell according to the frame structure, determined by the processing module, of the serving cell. a first part comprising a symbol used for downlink transmission; a second part: a guard period; and a third part comprising a symbol used for uplink control information transmission and/or sounding reference signal SRS transmission; and a fourth part comprising a symbol that is dynamically or half-statically configured to be used for downlink transmission or for uplink data transmission, wherein a quantity of symbols comprised in the first part is one, a length of the guard period is one symbol, a quantity of symbols comprised in the third part is one, and a quantity of symbols comprised in the fourth part is eleven; or the first part comprises seven symbols, a length of the guard period is one symbol, the third part comprises one symbol, and the fourth part comprises five symbols; or the first part comprises eight symbols, a length of the guard period is one symbol, the third part comprises one symbol, and the fourth part comprises four symbols; and a transceiver module, configured to send and receive information in the serving cell according to the frame structure, determined by the processing module, of the serving cell.