It also should be noted that when the positions of the interleaved discovery resource elements are mapped to the discovery resource elements in the current discovery resource period, the starting position of the mapping may be mod(D,N*K), herein D is an integer not less than 0, types of parameters which can be adopted by D may be identical to types of parameters which can be adopted by A and will not be repeated herein. For example, when D=3, the positions of the discovery resource elements in the preceding discovery resource period of the current discovery resource period shown in FIG. 11a are interleaved and then mapped to the positions of the discovery resource elements in the current discovery resource period using the frequency priority mapping principle, as shown in FIG. 11b.

Embodiment 4

In an embodiment, time positions of discovery resource elements for sending device discovery signals are selected randomly in the time direction of discovery radio resources in a discovery resource period, and frequency positions of the discovery resource elements are determined according to a preset mapping relationship or a mapping relationship obtained by interleaving of an interleaver.

In an embodiment, the mapping relationship is k2=mod(k1+M,K); herein M is a constant of which the value is an integer, and types of parameters which can be adopted by M may be identical to types of parameters which can be adopted by A, and the meaning of each of the remaining parameters is the same as described above and will not be repeated herein.