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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用于前传中频复用无线电信号传输的基于 SNR 的预加重


我们为在信道中传输频率复用模拟信号的系统提出了一种 SNR 估计程序。它与所传输的无线电信号的类型无关，可以在不增加所需带宽且不中断信号传输的情况下执行。我们通过激光强度调制和直接检测来模拟频率复用 OFDM 信号在光通道中的传输，其中我们将估计的 SNR 与通道的分析 SNR 进行比较，展示了估计的准确性。我们还通过应用估计的 SNR 来导出用于传输信号的预加重来评估性能。在第一种评估场景中，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 信号呈现出较低的 SNR。相反，在第二种情况下，由于部署了预加重，所有信号都呈现非常接近的 SNR，这可以通过最大化通道输出处的最小 SNR 来优化信号传输。