A Novel Chaotic MIMO-OFDM System for Improved Performance in Future Cellular Wireless Networks

In recent years, the explosive growth of new generation wireless networks has spurred lot of research thrust particularly looking for a bandwidth efficient modulation and coding scheme. In this connection, researchers have recently turned up their attention towards chaotic communication systems and golden codes for its attractive benefits. This consequently had motivated us for two new proposals namely: code shiftedquadrature chaos shift keying (CS-QCSK) and modified golden codes with low complex decoder. The Code Shifted-Quadrature Chaos shift Keying (CS-QCSK) modulation technique with its code domain approach has proven to be the best among the conventional chaotic modulation schemes [4]. Similarly, in the coding scenario, modified Golden codes had been proven to exhibit better error performance than any other space time block codes through our earlier investigation in [14]. The aforementioned modulation scheme (CS-QCSK) and coding scheme (modified golden code) can be concatenated in an OFDM system to harvest an enhanced performance. The suitability of the proposed chaos based logic is tested in a multiple input multiple outputorthogonal frequency division multiplexing (MIMO-OFDM) system. The performance parameters like spectral efficiency, capacity and BER analysis is computed through simulation analysis. The obtained results were found very satisfactory, of course with a marginal increase in the process complexity. Key-Words: Chaotic MIMO-OFDM, modified golden codes, Code shifted quadrature chaos shift keying (CSQCSK), multiple input multiple output (MIMO), Orthogonal frequency division multiplexing (OFDM), low complex sphere decoder, Bit error rate, spectral efficiency