关键词: 通信技术, 预编码, 有限反馈, 矢量量化, 多输入多输出, 正交频分多址

Abstract: The feedback data for precoding in multicarrier systems increases linearly with an increase in the number of subcarriers.To solve this problem,a precoding scheme with limited feedback for MIMOOFDMA downlinks was proposed.First,a codebook of precoding matrices was constructed offline using the twovariable joint vector quantization algorithm.Then,the subcarriers were divided into subcarrier bands according to the correlation between subcarriers.And the receiver choosed the precoding matrices,the user,the angel parameter for each subcarrier band aiming at the capacity maximization.The indices of the precoding information were conveyed to the transmitter with limited bits of feedback.Finally,the transmitter obtained the information in its codebooks via the indices and then obtains precoding matrices for all the subcarriers by interpolation.Simulation results show that the proposed scheme achieves a larger capacity than the existing schemes with the same number of feedback bits.

Key words: communication, precoding, limited feedback, vector quantization, multiple input multiple output (MIMO), orthogonal frequency division multiple access (OFDMA)