标题： LoRa散射通信：时域、频域及误性能分析 显示英文标题

标题： LoRa Backscatter Communications: Temporal, Spectral, and Error Performance Analysis

摘要： 基于其低成本和低功耗特性，LoRa 反向散射（LB）通信系统可以被视为超低功耗广域网（LPWAN）的潜在候选方案。 本文从时域、频域以及误码性能等多个方面全面分析了 LB 调制的特性。 首先，我们提出了一个考虑标签有限负载数量的 LB 信号模型。 然后，我们研究了 LB 信号的频谱特性，并得到了功率谱的闭式表达。 最后，在加性白高斯噪声（AWGN）和双 Nakagami-m 衰落信道下，我们推导了两种解码器（即最大似然（ML）解码器和快速傅里叶变换（FFT）解码器）下的 LB 符号误码率（SER）。 频谱分析表明，只有当考虑相对较大的负载数量时，LB 的带外辐射才能满足欧洲电信标准化协会（ETSI）的规定。 对于误码性能而言，与传统 LoRa 不同的是，FFT 解码器并非最优选择。 然而，通过采用适度数量的负载，ML 解码器能够实现接近传统 LoRa 的性能。 显示英文摘要

摘要： LoRa backscatter (LB) communication systems can be considered as a potential candidate for ultra low power wide area networks (LPWAN) because of their low cost and low power consumption. In this paper, we comprehensively analyze LB modulation from various aspects, i.e., temporal, spectral, and error performance characteristics. First, we propose a signal model for LB signals that accounts for the limited number of loads in the tag. Then, we investigate the spectral properties of LB signals, obtaining a closed-form expression for the power spectrum. Finally, we derived the symbol error rate (SER) of LB with two decoders, i.e., the maximum likelihood (ML) and fast Fourier transform (FFT) decoders, in both additive white Gaussian noise (AWGN) and double Nakagami-m fading channels. The spectral analysis shows that out-of-band emissions for LB satisfy the European Telecommunications Standards Institute (ETSI) regulation only when considering a relatively large number of loads. For the error performance, unlike conventional LoRa, the FFT decoder is not optimal. Nevertheless, the ML decoder can achieve a performance similar to conventional LoRa with a moderate number of loads.