Date Added: Apr 2010
The IEEE 802.11n specifies MIMO techniques to enhance data rate in WLANs. However, using Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), it can support only point-to-point links. On the other hand, it is known that multiuser MIMO techniques significantly increase the spectral efficiency of a network. There are already some enhanced MIMO signal processing techniques available which enable concurrent multiuser transmissions by utilising multiuser interference cancellation techniques. Multiuser interference can also be cancelled in a distributed manner. To enhance IEEE 802.11n systems such that multiple users can transmit simultaneously, the authors propose a novel Cluster-Based CSMA/CA (CB-CSMA/CA) protocol.