Physical structure and reference signal utilization of enhanced physical downlink control channel for OFDM/OFDMA systems

摘要

A two-level physical structure is defined for better diversity for both distributed and localized transmission in enhanced physical downlink control channel (ePDCCH). First level is a physical unit of enhanced resource element groups (eREGs), where the group of REs is predefined for each eREG. Second level is a logical unit of enhanced control channel elements (eCCEs), where the group of eREGs is predefined or configurable by higher layer for each eCCE. For distributed transmission of ePDCCH, eCCE consists of several eREGs that are distributed in multiple non-contiguous PRBs spreading over the whole channel frequency. Downlink control information (DCI) is transmitted on a number of aggregated eCCEs according to the modulation and coding level required. The utilization reference signals of antenna ports for ePDCCH demodulation is based on the logical order of eCCEs and the aggregation level for DCI transmission.

主权项

1. A method of decoding downlink control information by a user equipment (UE) in an OFDM/OFDMA system, the method comprising:
(a) receiving a control signal from a base station to determine received physical resource blocks (PRBs) that carry the downlink control information; (b) determining a set of candidate enhanced physical downlink control channels (ePDCCHs) within the PRBs, wherein each ePDCCH is associated with a set of enhanced control channel elements (eCCEs) for ePDCCH transmission; (c) collecting a plurality of enhanced resource element groups (eREGs) for each eCCE, wherein each eCCE consists of a number of eREGs based on an eCCE to eREG mapping rule; (d) collecting a plurality of resource elements (REs) for each eREG, wherein each eREG consists of a number of REs based on an eREG to RE mapping rule; and (e) decoding the downlink control information that are mapped to the collected REs.