Differential Precoding Scheme of LTE Systems over Temporally Correlated Channels

In this paper, a novel differential precoding scheme is proposed for LTE systems. The proposed scheme utilizes a differential codebook to update the precoding matrix. Due to the temporal correlation of adjacency time slots in temporally correlated channels, the current precoding matrix is restricted in a limited scope around the previous precoding matrix. This approach utilizes the differential information of the channel instead of quantizing the whole channel subspace, which involves less quantization distortion. The proposed precoding scheme has perfect compatibility with the conventional LTE precoding scheme. So, it has the good properties of LTE codebooks. We analyze the capacity and SER of the differential precoding scheme and compare the results with the performances of other existing precoding schemes.