Whenever there is a collision involving several
transmitted packets, the traditional approach for MAC (Medium
Access Control) protocols is to discard all packets involved and
request their retransmission, with a consequent loss in the
overall throughput. Based on conventional Multiple Input
Multiple Output (MIMO) techniques, a multipacket detector for
OFDM schemes (Orthogonal Frequency Division Multiplexing)
which does not discard the packets involved in a collision has
been recently proposed. One of the major problems in resolving
collisions using the multipacket detector is to discover how many
and which users were transmitting. In this paper we will present
a method to solve this problem.