A scheme of MAC/PHY cross-layer design in MIMO ad hoc networks based on random number allocation strategy

It is well known that MIMO technology can provide additional space degrees of freedom and increase the channel capacity greatly. However, it is a challenge to design the MAC layer when using MIMO in ad hoc networks. In FT (Follow Traffic) scheme, RTS/CTSs are sent simultaneously and used to estimate the traffic load. The node allocates the channel estimation resources in order of decreasing received power of RTS. Though FT scheme greatly improves the throughput, the fairness among nodes is declined and the complexity of receivers is increased. To address the problem, this paper presents a scheme of MAC layer based on random number allocation strategy, in which the node allocates the channel estimation resources in an increasing order of random number in each RTS. The throughput performance of the proposed scheme is suboptimal, but it ensures the fairness and reduces the complexity of the receivers.