标题： LoRa背散射通信：时间、频谱和错误性能分析 显示英文标题

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

摘要： LoRa背散射（LB）通信系统由于其低成本和低功耗，可以被视为超低功耗广域网络（LPWAN）的潜在候选者。 在本文中，我们从多个方面全面分析了LB调制，即时间、频谱和误码性能特征。 首先，我们提出了一个考虑标签中负载数量有限的LB信号模型。 然后，我们研究了LB信号的频谱特性，得到了功率谱的闭合表达式。 最后，我们推导了在加性高斯白噪声（AWGN）和双Nakagami-m衰落信道中，使用两种解码器（最大似然（ML）解码器和快速傅里叶变换（FFT）解码器）的LB符号误码率（SER）。 频谱分析表明，只有当考虑相对较多的负载时，LB的带外发射才能满足欧洲电信标准协会（ETSI）的规定。 在误码性能方面，与传统的LoRa不同，FFT解码器并不是最优的。 然而，ML解码器可以在负载数量适中的情况下实现与传统LoRa相似的性能。 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.