Eliminating Inter-BSS Co-Channel Interference by MC-CDMA in WLANs

Multi-carrier code division multiple access (MC-CDMA) was proposed to improve capacities of wireless networks. Instead of increasing the data transmission rates of wireless links, the authors propose to assign independent data streams obtained by MC-CDMA for transmitting uplink and downlink traffic separately in order to eliminate the hidden-node and exposed-node problems between cochannel BSSs in WLANs. Simulations show that our scheme can improve network throughputs by 106% in an exposed-node scenario and by 113% in a hidden-node scenario. The authors also consider the hardware and MAC requirements of our scheme under different settings of physical carrier sensing range. The authors believe this is a first paper in the literature to assign MC-CDMA generated data streams in WLANs so as to mitigate the hidden-node and exposed-node problems.