In Single-Input Single-Output (SISO) wireless multi-hop networks, when two or more stations attempt to transmit at the same time in the same vicinity area, a collision will occur. In this case, the collided packets are discarded and then retransmitted later. In order to deal with collision and to maximize the system's throughput, we propose a new cross-layer design based on multiple transmit and receive antennas (MIMO) capabilities, called MIMOMAX. Transmit filter, receive filter and channel state information (CSI) are exchanged between the PHY and MAC layers to optimize the scheduling of simultaneous transmissions on the same channel. The performance evaluation is conducted using OPNET simulation tool. The results obtained through extensive simulations are compared with those of IEEE 802.11b/g/n single-hop and multi-hop wireless networks. We show that MIMOMAX is less efficient (low throughput and long delays) for single-hop networks. This is due to an under-utilization of channel Degrees of Freedom (DoFs). However, it always performs better (high throughput and low packet delay) than the 802.11b/g/n wireless multi-hop networks: up to 30% and 87% as improvements in network throughput compared to the IEEE 802.11n and IEEE 802.11g networks respectively. In addition, we illustrate that MIMOAX is robust and resists to the early network saturation problem.
['Hakim Badis', 'Abderrezak Rachedi']
Performance evaluation of MIMO-based MAC/PHY cross-layer design in multi-hop ad hoc networks