Performance analysis of space time coded fractal modulation in the presence of frequency selective fading

The use of orthogonal space time block codes (OSTBC) in conjunction with fractal modulation in the presence of frequency selective fading channels is considered. An L scale fractal modulation and coherent demodulation effectively converts the frequency selective channel into L flat fading channels per information symbol with random scale gains. The bit error performance analysis of the proposed scheme has been done. It has been shown that a diversity order of m_Tm_RL can be achieved. This increase in diversity order in comparison with that achieved for the OFDM case is at a cost of lower spectral efficiency. The transceiver complexity is comparable with the IFFT/FFT operations used in case of OFDM