Pdcch aggregation level in lte. 211 Table 6. The number of CCE's available for PDCCH depends on the size of control region, the cell bandwidth, the number of antenna ports in the downlink, and the resources occupied by PHICH. 1. TS 36. 3. Just thought of writing a small note on how aggregation level controls PDCCH decoding and its importance in a wireless channel. . The number of consecutive CCEs required to carry one PDCCH is called "Aggregation Level'. Table 7. Since a UE is not signalled about the aggregation level of each PDCCH, it has to blindly decode it. A physical downlink control channel consists of one or more control-channel elements (CCEs) as indicated in Table 7. Number of the symbols (L) for PDCCH can be 1,2, or 3. Now let's look into a little bit deeper and see how 'Number of PDCCH bits' is derived for each PDCCH. 1 shows these relations. The number of candidates and size of the search space for each PDCCH is a physical channel that carries downlink control information (DCI) and it has characteristics as described below. I. , the aggregation level equals number of CCEs per PDCCH. There are 4 different aggregation levels defined in LTE and they are 1, 2, 4 and 8 using which each DCI format is mapped on to the DL control symbols, The CCE aggregation level and power offset of the PDCCH is determined based on the data operating point corresponding to the equivalent spectrum efficiency of the UE plus a certain conservative quantity. Mapped to the first L OFDM symbols in every downlink subframe. (This 'L' value is informed to UE by PCFICH) The number of CCE's used for a PDCCH is termed aggregation level. 8. 1-1. 1-1: Supported PDCCH aggregation levels. The number of consecutive CCEs required to carry one PDCCH is called "Aggregation Level'. Higher level means lower coding rate, is more suitable for UEs with poor channel conditions. The CCE aggregation level is given by the PDCCH format and determines the number of PDCCH candidates in a search space. 2. e. ofkstnsioccxiqqvfhcohcjtcplhesippchxyyefkxtyedcvkou