Research of calculating CFI value used in LTE system

This paper investigated the traditional method to determine Physical Downlink Control Channel (PDCCH) format and Control Format Indicator (CFI) value in LTE (Long Term Evolution) system. A modified method to calculate CFI value and the PDCCH format was proposed. Firstly, this method determined the PDCCH format based on the channel conditions, and then calculated the number of Resource Elements (RE) occupied by all the downlink control channels and reference signals. Finally, determined the CFI value based on the calculated number. The simulation results show that this modified method can effectively eliminate the average number of PDCCH blind detection.