S for the transmission in the next subframe, the eNode B has to predict the link quality- that is, the SINR based on measurements in previous subframes (UL) or based on previous CQI reports (DL). Therefore, the predictability of the interference conditions has high importance from the MCS optimality point of view. Large and uncorrelated interference varia- tions from one subframe to the other make the link prediction very difficult. From this aspect, the intercell interference coordination function can have a positive effect not only in decreasing the level of interference but also in decreasing the time variation of the interference and thereby making the link quality more predict- able [29]. Finally, the selected MCS is signaled together with the downlink/uplink © 2009 by Taylor & Francis Group, LLC Long Term Evolution: 3GPP LTE Radio and Cellular Technology scheduling assignment to the UE on the DL control channel (PDCCH). This means that neither the UE nor the eNode B has to do blind decoding. The UE decodes the data received on PDSCH according to the MCS indicated on the PDCCH. In the UL, the eNode B decodes the UE transmission according to the MCS it has assigned to the UE associated with the UL grant. The power allocation is also under eNode B control, and it is tightly coupled to the MCS selection. A given MCS is optimal only at a given SINR. Therefore, the selection of the MCS is always done with a target SINR in mind. Then it is the responsibility of the power control function to set the transmit power levels such that the target SINR is reached. For the DL transmission, the eNode B distributes its power on the RBs according to the corresponding target SINRs. In the simplest case, the DL power is distributed uniformly over the RBs (i.e., no downlink power control is employed). For a close to optimum power allocation, the so-called water- filling power allocation might be used [10,11], whereby higher power is allocated to subcarriers whose fading and interference are in favorable conditions. However, the