Effect of Channel Estimation Errors on Adaptive Modulation Systems Subject to Rayleigh Fading

The adoption of the adaptive modulation scheme leads to robust and spectrally efficient transmissions. However, the performance of the adaptive modulation systems is affected by the accuracy of the channel state information, which can result in incorrect modulator decisions, causing a bit error rate degradation. In this paper, the authors evaluate the effect of channel estimation errors in adaptive modulation systems. A novel analytical framework is proposed to model the instantaneous estimated signal-to-noise ratio. Different from previous approaches, this model is not related to a specific estimation technique and can be used to compare channel estimation strategies with different accuracy levels.