There are mainly two types of cyclic prefix used.
1. Normal cyclic prefix
2. Extended cyclic prefix
For both the types, minimum values are defined as follows:
Normal Cyclic Prefix : There will be total 7 symbols per time slot . First symbol is 5.2 microseconds long while remaining 6 symbols would be 4.69 microseconds long
Extended cyclic prefix : There will be total 6 symbols per time slot and each symbol will be 16.67 microseconds long.