Chordal Hopping

 

Chordal hopping, also known as Chordal Hopping Spread Spectrum (CHSS), is a modulation technique used in wireless communication systems. It is a variation of the frequency-hopping spread spectrum (FHSS) technique, which involves rapidly switching the transmission frequency of a signal to avoid interference and improve the overall robustness of the communication link.

In chordal hopping, the frequency-hopping pattern is chosen such that it forms a "chord" on a mathematical space called the Grassmannian. This allows for more efficient use of the available frequency band, as well as better resistance to interference, compared to traditional FHSS.

Chordal hopping is particularly useful in situations where the available frequency band is limited and the number of users is large, such as in cellular networks and wireless sensor networks. It also finds its application in military communication and satellite communication systems.

Chordal hopping is a complex technique and requires a good mathematical understanding of the underlying principles and the use of advanced algorithms. It is a relatively new technique in the field of wireless communication and is still under active research.