A method for scheduling uplink data of a user, applicable to semi-persistent scheduling in a multi-periodicity mode in the case of a third proportional configuration mode of uplink and downlink sub-frames, TDD Configuration 2, in a 3GPP Long Term Evolution Time Division Duplex system, comprising: setting different values of periodicity offsets, delta, for semi-persistent scheduling in the multi-periodicity mode starting with respective uplink sub-frames in a radio frame; determining, from the set values of delta, periodicities of semi-persistent scheduling in the multi-periodicity mode starting with the respective uplink sub-frames in the radio frame; and scheduling uplink new transmission of a user data packet in the periodicities of semi-persistent scheduling in the multi-periodicity mode starting with the respective uplink sub-frames in the radio frame, characterized in that the different values of delta are set for semi-persistent scheduling in the multi-periodicity mode starting with the respective uplink sub-frames in the radio frame according to a ratio of uplink to downlink sub-frames and locations of the uplink sub-frames scheduled by a Physical Downlink Control Channel, PDCCH, wherein setting the different values of delta for semi-persistent scheduling in the multi-periodicity mode starting with the respective uplink sub-frames in the radio frame according to the ratio of uplink to downlink sub-frames and the locations of the uplink sub-frames scheduled by the PDCCH comprises: setting the value of delta for semi-persistent scheduling in the multi-periodicity mode starting with a first uplink sub-frame in a 10ms radio frame scheduled by the PDCCH as: Delta = 1 + number of DL sub − frames / 2; and setting the value of delta for semi-persistent scheduling in the multi-periodicity mode starting with a second uplink sub-frame in the 10ms radio frame scheduled by the PDCCH as: Delta = − 1 − number of DL sub − frames / 2; or setting the different values of delta for semi-persistent scheduling in the multi-periodicity mode starting with the respective uplink sub-frames in the radio frame according to the ratio of uplink to downlink sub-frames and the locations of the uplink sub-frames scheduled by the PDCCH comprises: setting the value of delta for semi-persistent scheduling in the multi-periodicity mode starting with a first uplink sub-frame in a 10ms radio frame scheduled by the PDCCH as: Delta = − 1 − number of DL sub − frames / 2; and setting the value of delta for semi-persistent scheduling in the multi-periodicity mode starting with a second uplink sub-frame in the 10ms radio frame scheduled by the PDCCH as: Delta = 1 + number of DL sub − frames / 2; wherein the number of DL sub-frames is the number of sub-frames available to transmit downlink data in the 10ms radio frame. setting different values of periodicity offsets, delta, for semi-persistent scheduling in the multi-periodicity mode starting with respective uplink sub-frames in a radio frame; determining, from the set values of delta, periodicities of semi-persistent scheduling in the multi-periodicity mode starting with the respective uplink sub-frames in the radio frame; and scheduling uplink new transmission of a user data packet in the periodicities of semi-persistent scheduling in the multi-periodicity mode starting with the respective uplink sub-frames in the radio frame, setting the value of delta for semi-persistent scheduling in the multi-periodicity mode starting with a first uplink sub-frame in a 10ms radio frame scheduled by the PDCCH as: Delta = 1 + number of DL sub − frames / 2; and setting the value of delta for semi-persistent scheduling in the multi-periodicity mode starting with a second uplink sub-frame in the 10ms radio frame scheduled by the PDCCH as: Delta = − 1 − number of DL sub − frames / 2; or setting the different values of delta for semi-persistent scheduling in the multi-periodicity mode starting with the respective uplink sub-frames in the radio frame according to the ratio of uplink to downlink sub-frames and the locations of the uplink sub-frames scheduled by the PDCCH comprises: setting the value of delta for semi-persistent scheduling in the multi-periodicity mode starting with a first uplink sub-frame in a 10ms radio frame scheduled by the PDCCH as: Delta = − 1 − number of DL sub − frames / 2; and setting the value of delta for semi-persistent scheduling in the multi-periodicity mode starting with a second uplink sub-frame in the 10ms radio frame scheduled by the PDCCH as: Delta = 1 + number of DL sub − frames / 2; wherein the number of DL sub-frames is the number of sub-frames available to transmit downlink data in the 10ms radio frame. setting the value of delta for semi-persistent scheduling in the multi-periodicity mode starting with a first uplink sub-frame in a 10ms radio frame scheduled by the PDCCH as: Delta = − 1 − number of DL sub − frames / 2; and setting the value of delta for semi-persistent scheduling in the multi-periodicity mode starting with a second uplink sub-frame in the 10ms radio frame scheduled by the PDCCH as: Delta = 1 + number of DL sub − frames / 2;