The technical schemes described in the embodiments of the present disclosure are applicable to cellular wireless communication systems or the Internet. Technologies used by common cellular wireless communication systems include Code Division Multiplexing Access (CDMA) technology, Frequency Division Multiplexing Access (FDMA) technology, Orthogonal-FDMA (OFDMA) technology and Single Carrier-FDMA (SC-FDMA) technology. For example, the downlink (or called forward link) of a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE)/LTE-Advanced (LTE-A) cellular communication system is based on the OFDMA technology and the uplink (or called reverse link) is based on the SC-FDMA technology. In future, it is possible that a hybrid multiple-access technology can be supported on a link.

In an OFDMA/SC-FDMA system, radio resources for communication are in a two-dimensional time-frequency form.

For example, for an LTE/LTE-A system, communication resources of the uplink and the downlink are divided in the time dimension by taking a radio frame as a unit; each radio frame is 10 ms (millisecond) in length, and includes 10 subframes with the length of 1 ms; each subframe includes two slots with the length of 0.5 ms. As shown in FIG. 2, according to different configurations of the periodic prefix (CP), each slot includes 6 or 7 OFDM or SC-FDM symbols.