Guard interval

Guard intervals, also known as guard intervals are used in communications technology, to prevent mix certain transfers. They increase the immunity to propagation delays, echoes and reflections against the digital data are generally very vulnerable. The length of the guard interval will then decide on how prone to failure is a transfer. The longer such an interval, the better it protects against interference, however, is the lower the channel efficiency.

In COFDM each symbol is preceded by a guard interval. Disorders, such as echoes, which fall in the interval, have no effect on the decoded signal from the receiver, since the guard interval when decoding is not considered.

In TDMA the time each user ends with a guard interval in order to limit the impact of transmission delays and thus prevent data loss and reduce interference of the following users.

  • Modulation (technology)