In accordance with yet another aspect of the embodiment, another mapping relationship is recorded. The process of determining the mapping relationship includes: interleaving frequency positions of discovery resource elements in the preceding discovery resource period of the current discovery resource period using an interleaver; establishing a mapping relationship between the frequency positions of the discovery resource elements in the preceding discovery resource period of the current discovery resource period and frequency positions of a discovery resource elements in the current discovery resource period according to the result of the interleaving.

Thus, the frequency positions of the discovery resource elements for sending device discovery signals in the current discovery resource period are determined according to the frequency positions of the discovery resource elements which send the device discovery signals in the preceding discovery resource period of the current discovery resource period and the mapping relationship. The interleaver, which may be an interleaver defined by an LTE system, may be designed with reference to LTE protocol 36.212.

Still assuming that K=8, the frequency positions of the discovery resource elements which send the device discovery signals in the preceding discovery resource period of the current discovery resource period are identified by a coordinate (n1, k1) (n1=1, k1=2), and positions 0-7 of frequency resources in the preceding discovery resource period of the current discovery resource period are changed to <1,5,3,7,0,4,2,6> after being interleaved by the interleaver of the LTE system, that is, k2=6.