Reduced-Complexity FFT-Spread Multicarrier Faster-Than-Nyquist Signaling in Frequency-Selective Fading Channel
Reduced-Complexity FFT-Spread Multicarrier Faster-Than-Nyquist Signaling in Frequency-Selective Fading Channel
复制标题
频率选择性衰落信道中复杂度降低的 FFT 扩展多载波快于奈奎斯特信令
DOI：
10.1109/ojcoms.2022.3160721
复制
发表时间：
2022
影响因子：
7.9
通讯作者：
Sugiura Shinya
中科院分区：
文献类型：
--
作者：
Ishihara Takumi;Sugiura Shinya
在本文中，我们提出了一种新的降低复杂度的快速傅里叶变换（FFT）扩展多载波快于奈奎斯特（MFTN）信号与功率分配的频率选择性衰落信道。所提出的MFTN信令的信息速率是通过依赖于特定于FTN的符号间干扰矩阵和噪声协方差矩阵的循环近似来推导的。这使我们能够构成有效的计算预编码和加权矩阵。优化功率分配系数，使得近似信息速率最大化。我们的仿真结果表明，所提出的方案与功率分配实现的误比特率（BER）性能接近传统的特征值分解（EVD）预编码FTN信令对应的是最佳的可实现的信息速率，同时显着降低计算复杂度低的顺序。虽然所提出的方案表现出类似于传统的EVD预编码对应的高峰值平均功率比由于基于FFT的预编码的影响，它实现了更好的BER性能比传统的开环单载波FTN信令方案和奈奎斯特信令方案，采用相同的根升余弦成形滤波器。还证实了所提出的MFTN信令方案不遭受任何显著的带宽加宽。
In this paper, we propose novel reduced-complexity fast Fourier transform (FFT)-spread multicarrier faster-than-Nyquist (MFTN) signaling with power allocation for a frequency-selective fading channel. The information rate of the proposed MFTN signaling is derived by relying on the circulant approximation of the FTN-specific intersymbol interference matrix and noise covariance matrix. This allows us to constitute efficient calculations of precoding and weighting matrices. The power allocation coefficients are optimized such that the approximated information rate is maximized. Our simulation results demonstrate that the proposed scheme with power allocation achieves the bit error ratio (BER) performance close to the conventional eigenvalue-decomposition (EVD)-precoded FTN signaling counterpart that is optimal in terms of an achievable information rate while significantly reducing the computational complexity as low as the order of. While the proposed scheme exhibits a high peak-to-average-power ratio similar to the conventional EVD-precoded counterpart due to the effects of FFT-based precoding, it achieves better BER performance than the conventional open-loop single-carrier FTN signaling scheme and the Nyquist signaling scheme, employing the same root-raised cosine shaping filter. It is also confirmed that the proposed MFTN signaling scheme does not suffer from any significant bandwidth broadening.