R-PrinciplesformappingVirtualResourceBlockstoPhysicalResourceBlocksinEUTRADownl.docVIP

3GPP TSG RAN WG1 Meeting #49 Tdoc R1-072392 Kobe, Japan, 7th – 11th May, 2007 Agenda Item: 7.12 Source: Philips, NXP Semiconductors, Mitsubishi Electric Title: Principles for mapping Virtual Resource Blocks to Physical Resource Blocks in EUTRA Downlink Document for: Discussion and Decision Introduction A number of previous contributions (e.g. [1]) have examined different alternatives for multiplexing distributed and localised downlink transmissions, and for mapping Virtual Resource Blocks (VRBs) to Physical Resource Blocks (PRBs). A previous contribution [2] which has now been submitted to many meetings discusses some of these proposals in more detail and makes some proposals for a way forward. We provide here a summary of the main points which we believe to be important for the solution. Principles for Multiplexing of Distributed and Localised Data The following key principles have been identified for the multiplexing: Distributed data transmissions should not interfere with the allocation of localised resource blocks – i.e. the users receiving localised data should not need to know the positions of distributed data symbols for other users. The multiplexing should be simple. This leads to a preference for RB-level multiplexing as for example in [3] – i.e. each PRB contains either data from a localised VRB (LVRB) or data from a distributed VRB (DVRB), but not both. Principles for Symbol Mapping of DVRBs to PRBs This should provide: as much diversity as possible for the distributed transmissions (as these will not benefit from channel-dependent scheduling); inter-cell interference randomisation, especially as different transmission powers and modulation schemes may be used for different users; simple mapping. We assume that the size of a DVRB is the same as the size of a LVRB, and a LVRB is mapped to exactly one PRB. The nature of distributed mapping means that each PRB contains data from multiple DVRBs; this is referred to as “ND-block divisio