A new transmission and multiple access scheme based on multicarrier CDMA for future highly mobile networks

In this paper, we propose a new transmission and resource allocation technique on multicarrier direct-sequence CDMA (MC-DS-CDMA). The proposed system allocates subcarriers and spreading codes to users by considering their current bandwidth requirements and frequency shifts caused by their movement. Through the use of low-correlation spreading codes in close subcarriers the scheme reduces the inter-carrier interference generated by high-speed users while keeping the inter-symbol interference at a low level due to the multicarrier transmission. The analysis and results show that a substantial mitigation of both the intercarrier interference and bit error ratio, without reducing the system bandwidth efficiency, can be achieved. That makes our proposed method a god candidate for future broadband highly-mobile networks.