Patent ID: 8625509

Claim:
A method of, at a base station, transmitting physical downlink control channel signals in a wireless communication system, the method comprising: spreading a plurality of signals using a spreading code with a predetermined spreading factor, multiplexing a plurality of spread signals to construct one or more spread signal groups, mapping one or more Physical Downlink Control Channels (PDCCHs) to first L Control Channel Elements (CCEs) of N CCEs, wherein each of the one or more PDCCHs carries Downlink Control Information (DCI) and wherein L≧1 and N≧2; mapping one or more Physical Hybrid ARQ Channels (PHICHs) to last M CCEs of the N CCEs, wherein each of the one or more PHICHs carries Hybrid ARQ Acknowledgement (HARQ-ACK) and wherein M=N−L≧1; interleaving the N CCEs in units of a Resource Element Group (REG); and transmitting the one or more PDCCHs and the one or more PHICHs using the interleaved N CCEs, wherein each CCE includes 9 consecutive REGs and each REG includes 4 neighboring available Resource Elements (REs) in an Orthogonal Frequency Division Multiplexing (OFDM) symbol.