Frekvensalternativ

Frekvensalternativ, also known as frequency hopping, is a technique used in wireless communication to improve the security and reliability of data transmission. In frequency hopping, the transmitter and receiver change frequencies in a predetermined pattern, known as a hopping sequence, during the transmission of data. This technique helps to minimize interference from other signals and reduces the likelihood of eavesdropping, as an attacker would need to follow the hopping sequence to intercept the communication.

Frequency hopping can be implemented using various methods, including fast frequency hopping (FFH) and slow frequency hopping (SFH). FFH changes frequencies multiple times per data symbol, providing robust protection against interference and jamming. SFH, on the other hand, changes frequencies once per data symbol, offering a balance between security and data rate.

Frequency hopping is widely used in military and secure communications, as well as in some commercial applications, such as Bluetooth and Zigbee. It is particularly useful in environments with high levels of interference or where security is a critical concern. However, frequency hopping can also introduce complexity in the design of the communication system, as it requires synchronization between the transmitter and receiver to maintain the correct hopping sequence. Additionally, the performance of frequency hopping systems can be affected by the availability of frequency channels and the efficiency of the hopping sequence.