Inserting virtual carrier in conventional OFDM host carrier in communications system

摘要

A base station for communicating data to and from a plurality of mobile terminals over a plurality of OFDM sub-carriers within a coverage area provided by the base station. The base station arranged to allocate transmission resources provided by a first group of the plurality of OFDM sub-carriers within a first frequency band to mobile terminals of a first type and to allocate transmission resources provided by a second group of the plurality of OFDM sub-carriers within a second frequency band to terminals of a second type, the second group being smaller than the first group and the second frequency band being selected from within the first frequency band. The base station is also arranged to transmit control information comprising resource allocation information for terminals of the first type over a first bandwidth corresponding to the combined first and second groups of OFDM sub-carriers and to transmit control information comprising resource allocation information for terminals of the second type over a second bandwidth corresponding to the second group of OFDM sub- carriers.