Multiple Frequency Offsets Pre-Correction Based on Enhanced Limited Feedback Precoding for Distributed MIMO System

In this paper, we consider the problem of multiple frequency offsets pre-correction in distributed multi-input multi-output (MIMO) systems. In practical distributed MIMO system, each pair of transmit and receive antenna has a different frequency offset and the received signal at each receiver is the summation of all the transmitted signals. These multiple frequency offsets make frequency compensation difficult if not impossible. In the paper, taking advantage of equivalent channel matrix with frequency offsets information, an enhanced limited feedback precoding (ELFP) algorithm is proposed to pre-correct the effect of frequency offsets. Simulation results show that the proposed scheme works as well as the system without frequency offsets even if the normalized frequency offsets is as high as 20%.