different scrambling codes when carried on the same scrambling code different dedicated pilots are differentiated by channel codes the channel codes can be either predefined or allocated dynamically in the former case there is no need to inform the ue of the channel codes used for the pilots but the signalling informing the ue of the change of group area is still required when different group area specific dedicated pilots are carried on different scrambling codes it is preferable to have pre defined channel codes for the pilots note that sfn transmission occupies much more channel codes than spatial reuse it is preferable to allocate scrambling codes respectively for spatial reuse ues and sfn ues so that the channel codes occupied by sfn transmission can be freed besides trps close to each other may use the same scrambling code to avoid too much inter scrambling code interference while trps far apart from each other may use different scrambling code to have more usable channel codes in this way a balance between channel code and power resources can be achieved one major advantage with the group area specific dedicated pilot scheme is that the code and power consumption is relatively small the above dedicated pilot schemes can be applied separately or in any combination for example ue specific dedicated pilots can be adopted for high speed ues and or high data rate ues which account for only a small fraction of all ues in a cell and will not consume excessive resources while group area specific pilots can be adopted for low speed ues with.