International Mobile Subscriber Identification Number (IMSI);

a part of the IMSI, for example, a certain number of bits (e.g., 10 or 12 bits) of the IMSI;

Temporary Mobile Subscriber Identity (TMSI);

a part of the TMSI, for example, a certain number of bits (e.g., 10 or 12 bits) of the TMSI;

a Radio Network Temporary Identifier (RNTI) of a UE, including a Cell Radio Network Temporary Identifier (Cell-RNTI) and an RNTI related to D2D; and

other IDs of the UE, for example, an application ID (APP ID).

In the formula described above which generates the initial sequence of the pseudorandom sequence, the denominator may be a constant, for example, a constant greater than N*K.

In the next place, the pseudorandom sequence is generated according to the initial sequence and the pseudorandom sequence generation manner.

The pseudorandom sequence may be generated with reference to the manner of implementing the LTE system. Specifically, the LTE standard protocol 36.211 may be referred.

In the next place, the serial numbers of the positions of the discovery resource elements for sending the device discovery signals are determined according to the pseudorandom sequence and at least one of the following parameters: an index of the discovery resource period and the number of the discovery resource elements in the discovery resource period.