Channel estimation in rotating polarization based wireless communication systems

In a slow fading/fixed environment, a deep fade might last for several symbol durations, and all the transmissions during such a deep fade become highly unreliable. Rotating polarization is an RF technique to artificially induce fading in a static environment, and thus reduce the chance of prolonged deep fades. However, this technique makes the channel vary at a high rate and hence increases the complexity of channel estimation. In this paper, we look at channel estimation in systems using rotating polarization. Drawing parallels from MIMO systems, we propose a technique for designing a training sequence that reduces the complexity of channel estimation while providing good performance in an induced fast fading environment. We analyse the performance of the least-squares and minimum mean square error channel estimation techniques with rotating polarization.