Configuration of uplink and downlink grant search spaces in a OFDM-based mobile communication system

摘要

The invention relates to methods for detecting at least one of a downlink grant and an uplink grant within a sub-frame of an OFDM-based mobile communication system. The invention provides a reception apparatus (e.g. a relay node or a mobile terminal) that are adapted to perform these methods. The invention defines the uplink grant search space to form a subset of the downlink grant search space. In other words, in the frequency domain, the uplink grant search space is defined on a subset of the resource block pairs that form the downlink search space. This configuration allows downlink data to be mapped to the remaining resources outside the uplink grants search space and the resources used for a downlink grant. Furthermore, the downlink grants comprise an indication of whether the uplink grant search space in the sub-frame comprises (user) data or not.