A transmit end, comprising: a selection unit, configured to: select, for each of N receive ends from preset N different hash function groups, one group that has a same sequence number as that of the receive end, wherein each of the N different hash function groups comprises M different hash functions; a mapping unit, configured to: map a MAC address of the receive end into a number X by successively using each hash function comprised in the hash function group selected by the selection unit, and denote the number X by using a first sequence, to obtain M first sequences corresponding to the receive end, wherein X is an integer greater than or equal to 1, and the first sequence is a sequence whose X th bit is 1 and remaining bits are 0s; a calculation unit, configured to: perform a bitwise OR operation on the M first sequences obtained by the mapping unit, to obtain an identification sequence corresponding to the receive end; wherein the calculation unit is further configured to: obtain, according to M first sequences that are corresponding to each of the N receive ends and obtained by the mapping unit, N identification sequences corresponding to the N receive ends; and the calculation unit is further configured to: perform a bitwise OR operation on the N identification sequences to obtain a Bloom sequence; an encoding unit, configured to encode and modulate the Bloom sequence to map the Bloom sequence onto an orthogonal frequency division multiplexing OFDM symbol by using a subcarrier; an aggregation unit, configured to form an aggregation frame by using a pilot signal, the OFDM symbol, the N identification sequences, and data corresponding to the N receive ends; and a sending unit, configured to send the aggregation frame obtained by the aggregation unit to the N receive ends; wherein the aggregation unit is specifically configured to: aggregate data segments corresponding to all the receive ends, and add, to the front of a data segment corresponding to each receive end, an identification sequence of the receive end corresponding to the data segment to form a load data segment; and place the OFDM symbol before the load data segment and after the pilot signal to form the aggregation frame; and wherein N and M are integers greater or equal to 2. a selection unit, configured to: select, for each of N receive ends from preset N different hash function groups, one group that has a same sequence number as that of the receive end, wherein each of the N different hash function groups comprises M different hash functions; a mapping unit, configured to: map a MAC address of the receive end into a number X by successively using each hash function comprised in the hash function group selected by the selection unit, and denote the number X by using a first sequence, to obtain M first sequences corresponding to the receive end, wherein X is an integer greater than or equal to 1, and the first sequence is a sequence whose X th bit is 1 and remaining bits are 0s; a calculation unit, configured to: perform a bitwise OR operation on the M first sequences obtained by the mapping unit, to obtain an identification sequence corresponding to the receive end; wherein the calculation unit is further configured to: obtain, according to M first sequences that are corresponding to each of the N receive ends and obtained by the mapping unit, N identification sequences corresponding to the N receive ends; and the calculation unit is further configured to: perform a bitwise OR operation on the N identification sequences to obtain a Bloom sequence; an encoding unit, configured to encode and modulate the Bloom sequence to map the Bloom sequence onto an orthogonal frequency division multiplexing OFDM symbol by using a subcarrier; an aggregation unit, configured to form an aggregation frame by using a pilot signal, the OFDM symbol, the N identification sequences, and data corresponding to the N receive ends; and a sending unit, configured to send the aggregation frame obtained by the aggregation unit to the N receive ends; wherein the aggregation unit is specifically configured to: aggregate data segments corresponding to all the receive ends, and add, to the front of a data segment corresponding to each receive end, an identification sequence of the receive end corresponding to the data segment to form a load data segment; and place the OFDM symbol before the load data segment and after the pilot signal to form the aggregation frame; and wherein N and M are integers greater or equal to 2.