Investigating the Impact of Spectrum Efficient Ofdm-mimo and Mc-cdma-mimo Communication System for Its

For future wireless communications systems, parameters like high transmission data rate, spectral efficiency, and reliability are extremely necessary. In a multipath wireless channel, deploying multiple antennas at both the transmitter and receiver help us achieve higher data rate without increasing the total transmission power or bandwidth. When perfect knowledge of the wireless channel conditions is available at the receiver, the capacity has been shown to grow linearly with the number of antennas. The implementation of wideband MIMO system imposes major challenge to hardware designers due to the huge processing power required for MIMO detection. This can be overcome by using optimizing channel coding and MIMO detection. Orthogonal frequency division multiplexing (OFDM) and multicarrier code division multiple access (MC-CDMA) have been attracting much attention in this field of study. In this paper, a comparative study for OFDM-MIMO is presented regarding BER/PER performance and hardware complexity. All the simulations are conducted within MIMO-OFDM framework and with a packet structure similar to that of IEEE 802.11a/g standard. We have derived a channel capacity expression for MC-CDMA MIMO in a multi-user environment and confirmed by numerical evaluation that MC-CDMA MIMO provides a slightly higher capacity than OFDM 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. As per the results obtained, the MC-CDMA-MIMO appears to be an affordable solution for wideband MIMO system targeting Giga-bit speed wireless transmission and ITS applications. Index Terms – CDMA, OFDM, MIMO, V-BLAST and ITS.