By combining traditional frequency hopping ideas with the concepts of subcarriers and sampling points in OFDM baseband systems, this paper proposes a frequency hopping technology within the baseband called micro frequency hopping. Based on the concept of micro frequency hopping, this paper proposes a micro frequency hopping spread spectrum modulation method based on cyclic frequency shift and cyclic time shift, as well as a micro frequency hopping encryption method based on phase scrambling of baseband signals. Specifically, this paper reveals a linear micro frequency hopping symbol with good auto-correlation and cross-correlation feature in both time domain and frequency domain. Linear micro frequency hopping symbols with different root $R$ have good cross-correlation feature, which can be used in multi-user communication at same time and same frequency. Moreover, there is a linear relationship between the time delay and frequency offset of this linear micro frequency hopping symbol, making it suitable for time delay and frequency offset estimation, also for ranging, and speed measurement. Finally, this paper also verifies the advantages of micro frequency hopping technology through an example of a linear micro frequency hopping spread spectrum multiple access communication system. The author believes that micro frequency hopping technology will be widely used in fields such as the Internet of Things, military communication, satellite communication, satellite positioning, and radar etc.

翻译：本文通过将传统跳频思想与OFDM基带系统中的子载波和采样点概念相结合，提出了一种基带内的跳频技术，称为微跳频。基于微跳频的概念，本文提出了基于循环频移和循环时移的微跳频扩频调制方法，以及基于基带信号相位扰乱的微跳频加密方法。具体而言，本文揭示了一种在时域和频域均具有良好自相关与互相关特性的线性微跳频符号。不同根$R$的线性微跳频符号具有良好的互相关特性，可用于同时同频的多用户通信。此外，该线性微跳频符号的时延与频偏之间存在线性关系，使其适用于时延与频偏估计，也可用于测距与测速。最后，本文还通过一个线性微跳频扩频多址通信系统的实例验证了微跳频技术的优势。作者认为，微跳频技术将在物联网、军事通信、卫星通信、卫星定位及雷达等领域得到广泛应用。