A variable-rate modulation scheme for transmit diversity in wireless multimedia communications

In future wireless multimedia communications, adaptive modulation and transmit diversity are two of the most important techniques. Adaptive modulation can efficiently use the channel spectra,and provide flexible data rate access. Transmit diversity is a more attractive technique to mitigate the channel fading. We propose a new simple variable-rate modulation scheme for transmit diversity. Compared to the traditional fixed rate modulation scheme, theoretical analysis and simulation results have shown that our proposed modulation scheme can provide more throughput and significant signal to noise ratio (SNR) gain.