Communication apparatus and method for receiving a response signal

摘要

A radio communication mobile station device reduces the number of blind decoding processes at a mobile station without increasing overhead by report information. The device includes a judgment unit which judges a particular PUCCH to which a response signal corresponding to the downstream line data is to be allocated among a plurality of PUCCH, according to a CCE occupied by PDCCH allocated to a particular search space corresponding to a CCE aggregation size of the PDCCH to which allocation information destined to the local station is allocated among search spaces changing in accordance with the CFI value; and a control unit which controls a cyclic shift amount of a ZAC sequence of the response signal and a block-wise spread code sequence according to a correspondence between CCE occupied by PDCCH allocated to a particular search space and a particular PUCCH resource, the correspondence changing in accordance with the CFI value.

主权项

1. A communication apparatus comprising:
a transmitting section configured to transmit, to a terminal, a downlink control channel on one or more control channel element(s) (CCE(s)) with consecutive CCE number(s) in a search space that is comprised of a plurality of CCEs; and a receiving section configured to receive a response signal, which is transmitted from the terminal on a uplink control channel, an index of the uplink control channel being associated with a CCE number of the CCE, on which the downlink control channel is transmitted, wherein: the search space is comprised of the plurality of CCEs corresponding to a plurality of downlink control channel candidates to be attempted to be decoded; and the search space for each aggregation size corresponding to a number of the CCE(s), on which the downlink control channel is transmitted, is comprised of the plurality of CCEs that are defined by starting on a CCE with a CCE number, which depends on both a total number of CCEs in a subframe and the aggregation size, and at least part of the search space for the each aggregation size is comprised of CCEs with consecutive CCE numbers.