Analytical link performance evaluation of LTE downlink with carrier frequency offset

In this paper, we evaluate the link performance of a practical OFDM system, namely Long Term Evolution (LTE) downlink, with imperfect frequency synchronization. The analytical expression of the post-equalization Signal to Interference and Noise Ratio (SINR) is derived and compared with results obtained from a standard compliant simulator. An excellent agreement is obtained. Due to the fact that equalization is carried out based on the constant channel knowledge within one subframe, other than the inter-carrier interference, the common phase error introduced by the residual carrier frequency offset degrades the SINR severely. This implies that in order to eliminate the link performance loss, frequency synchronization of rather high accuracy is required.