We propose an SNR estimation procedure for systems that transmit frequency-multiplexed analog signals in a channel. It is agnostic to the type of radio signal transmitted, can be performed without increasing the required bandwidth, and without interrupting the transmission of the signals. We simulate the transmission of frequency-multiplexed OFDM signals in an optical channel with intensity modulation of the laser and direct detection, where we show the accuracy of the estimation comparing the estimated SNR to the analytical SNR of the channel. We also evaluate the performance by applying the estimated SNR to derive a pre-emphasis used to transmit the signals. In a first evaluation scenario, the OFDM signals transmitted at higher carrier frequencies without pre-emphasis present lower SNR because of the channel response. In contrast, in a second scenario, all the signals present very close SNR due to the pre-emphasis deployed, which could allow optimizing signal transmission by maximizing the minimum SNR at the channel output.

中文翻译：

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基于 SNR 的预加重用于前传中频率复用无线电信号的传输

我们为在信道中传输频率复用模拟信号的系统提出了 SNR 估计程序。它与传输的无线电信号类型无关，可以在不增加所需带宽和不中断信号传输的情况下执行。我们使用激光强度调制和直接检测来模拟光信道中频率复用 OFDM 信号的传输，我们将估计的 SNR 与信道的分析 SNR 进行比较，显示了估计的准确性。我们还通过应用估计的 SNR 来获得用于传输信号的预加重来评估性能。在第一个评估场景中，由于信道响应，在没有预加重的情况下以较高载波频率传输的 OFDM 信号呈现较低的 SNR。相比之下，