Polarization mode dispersion estimation algorithm based on selection combining in dual-polarized channels

Abstract

In time-varying multipath channels, the performance of polarization technologies in wireless networks such as polarization diversity, polarization multiplexing and polarization modulation is susceptible to polarization mode dispersion (PMD). PMD is an important element to describe the depolarization effects of wireless channels and is useful in polarized signal processing. We can use PMD information to choose modulation modes which can improve energy efficiency, or to choose power allocation model which can improve data transmission rate. Therefore, this paper presents a PMD estimation algorithm based on selection combining to obtain PMD information of time-varying multipath channels. The proposed algorithm can be divided into two steps. Firstly, to improve the accuracy of estimation, we use selection combining at the receiver, which choose signals having higher SNR from horizontal and vertical component. Then, We use selected signals to estimate multipath delay. Secondly, we compute PMD directly by using delay spread and max delay which can be calculated from multi-path delay. The performance of the proposed PMD estimation algorithm is evaluated by the mean square error (MSE). Theoretical analysis and simulation show that the proposed algorithm have better estimation performance compared with PMD estimation algorithm using single component.