To enable the efficient and low latency machinetype communications (MTC) over long term evolution (LTE), a contention based access (CBA) method is proposed. With CBA, UEs transmit packets on the randomly selected resource without having any UE specific scheduled resources. To address the problem of collision caused by CBA in high traffic load,
eNB exploits the MU-MIMO detection technique to decode radio network temporary identifier (RNTI) of the collided UEs and use this information to perform a regular scheduling in subsequent subframe. The latter is also exploited on the data portion to increase the probability of receiving the packet on the first transmission, even in the case of contention. Detailed low layer signaling enhancement to implement this CBA technique in current LTE specification (Rel. 10) is also presented. Simulation results demonstrate that CBA can significantly outperform the existing uplink channel access methods.