Wireless MAC design with selective decoding schemes

IEEE 802.11 MAC designs encounter two problems: (1) interferences from neighboring nodes or from hidden nodes and (2) collision from simultaneous transmissions within the same contention floors. This paper presents the optimum selective decoding schemes in MAC protocol (OSDS-MAC) for MIMO Ad-hoc networks. It is able to mitigate interferences by using a developed minimum mean-squared error (MMSE) technique. This interference mitigation combined to ML decoding schemes for the Alamouti coding achieves to receive and differentiate the data streams from other co-channel users. As a result, it allows a pair of simultaneous transmissions to the same or different receivers which increase the network utilization. Moreover, the presented three decoding schemes are optimally selected corresponding to the three time line operations determined by the number of RTSs and the type of CTS packets. In simulation, consider two cases which are (1) single data stream and (2) two independent data streams which are simultaneously transmitted from the two independent transmitters. Log-distance path loss model is used as a propagation condition, and MIMA-MAC is used for comparison.