A study on channel capacities of MC-CDMA MIMO and OFDM MIMO

For the development of future wireless communication systems, an extremely spectrum-efficient transmission technology is required. Orthogonal frequency division multiplexing (OFDM) and multi-carrier code division multiple access (MC-CDMA) have been attracting much attention. The use of multiple-input multiple-output (MIMO) transmission is essential to achieve a very high speed data transmission with the limited bandwidth. In our previous paper, assuming perfect cancellation of inter-code interference (ICI), we have derived a channel capacity expression for MC-CDMA MIMO in a multi-cell environment and confirmed by numerical evaluation that MC-CDMA MIMO provides a slightly higher capacity than OFDM MIMO. In this paper, we theoretically show by using Jensen¿s inequality that the channel capacity of MC-CDMA MIMO assuming perfect ICI cancellation (ICIC) is always higher than or equal to that of OFDM MIMO. Furthermore, we compare the channel capacities of MIMO multiplexing and multiple single-input multiple output (SIMO) system.