Utilising partially overlapped channels for OFDM-based 802.11 WLANs

This paper proposes a modified subcarrier design of the orthogonal frequency-division multiplexing (OFDM) scheme for supporting the concept of partially overlapped channels (POC) in wireless local area networks. Our proposed scheme, named as “channel-overlapped OFDM (CO-OFDM)”, enables the POC in OFDM by reconfiguring its subcarrier alignment and creating subcarrier subsets that allow clear transmission between nodes by using different non-orthogonal channels. This makes the nodes maintain connectivity with each other through beaconing even though they use adjacent channels. In addition, simultaneous data transmission can be achieved via channel switching and MIMO-based data transmission, thereby increasing the overall throughput of the network. Further, we integrate our CO-OFDM into IEEE 802.11a/g/n/ac-based wireless networks and analyse its superiority over existing protocols through mathematical modelling. Evaluation results show that the proposed CO-OFDM guarantees over 300% performance increase in network capacity.