Wideband excitation signals are essential in bioimpedance spectroscopy for measurements in a time ensuring a quasi-stable measurement condition. In particular, for wearable biomedical systems, due to limited system resources, several aspects regarding measurement time, crest factor, slew rate requirements, frequency distribution, amplitude spectrum, and energy efficiency need to be thoroughly investigated. In this paper, we present an investigation of excitation signals, which includes not only the theoretical aspects but also aspects of real implementation on microcontroller-based systems. At a fixed number of samples and sampling rate, we investigate the implementability of signal frequencies and the resulting spectral efficiency. We focus on sources of signal distortion due to timer and amplitude deviations. The results show that for 4096 samples and a sampling frequency of 1 MHz, wideband signals are 2.76 times faster than a stepped frequency sweep. The multisine signal provides a better energy efficiency and has a lower slew rate requirement on hardware (around 0.3 V s⁻¹), but has a relatively high crest factor, even after optimization. An exemplary investigation of the distortion of the time/frequency and amplitudes following implementation on a standard industrial advanced RISC machines microcontroller has shown that a sampling rate compensation is required to overcome timer inaccuracies. Furthermore, non-return-to-zero binary signals are more sensitive to distortion due to hardware-related issues and have a lower signal-to-distortion-and-noise (SINAD) ratio than 24 dB, which is lower than the multisine signal, having a SINAD of 31 dB.

宽带激励信号在生物阻抗光谱中是必不可少的，可在确保准稳定测量条件的时间内进行测量。特别是对于可穿戴生物医学系统，由于系统资源有限，需要对测量时间、波峰因数、压摆率要求、频率分布、幅度谱和能效等几个方面进行深入研究。在本文中，我们对激励信号进行了调查，其中不仅包括理论方面，还包括在基于微控制器的系统上的实际实施方面。在固定数量的样本和采样率下，我们研究了信号频率的可实现性和由此产生的频谱效率。我们专注于由定时器和幅度偏差引起的信号失真源。结果表明，对于 4096 个样本和 1 MHz 的采样频率，宽带信号比步进频率扫描快 2.76 倍。多正弦信号提供更好的能效，并且对硬件的压摆率要求较低（约 0.3 V s⁻¹ )，但具有相对较高的波峰因数，即使经过优化也是如此。在标准工业先进 RISC 机器微控制器上实施后，对时间/频率和幅度失真的示例性调查表明，需要采样率补偿来克服计时器的不准确性。此外，由于硬件相关问题，不归零二进制信号对失真更敏感，并且信噪比 (SINAD) 低于 24 dB，低于多正弦信号，SINAD 为 31 dB。