The focus of this letter is on the reduction of the large pilot overhead in orthogonal frequency division multiplexing (OFDM) based massive multiple-input multiple-output (MIMO) systems. We propose a novel joint channel estimation and equalization technique that requires only one pilot subcarrier, reducing the pilot overhead by orders of magnitude. We take advantage of the coherent bandwidth spanning over multiple subcarrier bands. This allows for a band of subcarriers to be equalized with the channel frequency response (CFR) at a single subcarrier. Subsequently, the detected data symbols are considered as virtual pilots, and their CFRs are updated without additional pilot overhead. Thereafter, the remaining channel estimation and equalization can be performed in a sliding manner. With this approach, we use multiple channel estimates to equalize the data at each subcarrier. This allows us to take advantage of frequency diversity and improve the detection performance. Finally, we corroborate the above claims through extensive numerical analysis, showing the superior performance of our proposed technique compared to conventional methods.
翻译:本信的重点是减少以大量多投入多输出(MIMO)为基础的正方位频率多输出(OFDM)系统中的大型实验性间接费用。我们建议采用新型联合频道估计和衡平技术,只需要一个试点子载体,按数量减少试点间接费用。我们利用覆盖多个子载体带的连贯带宽。这样可以使一组子载体与单个子载体的频道频率反应(CFR)相等。随后,所检测到的数据符号被视为虚拟试点项目,而它们的CFR则无需额外试点间接费用而更新。此后,剩余的频道估计和均衡可以滑动方式进行。我们采用这种方法,利用多个频道估计来平衡每个子载体的数据。这使我们能够利用频率多样性,提高探测性。最后,我们通过广泛的数字分析来证实上述主张,显示我们拟议技术与常规方法相比的优异性表现。