array(5) { [0]=> string(13) "2009 - Haiyou" [1]=> string(8) " Honglin" [2]=> string(97) " Yang - Cyclostationary signatures in OFDM-based cognitive radios with cyclic delay diversity.pdf" [3]=> string(7) " 917832" [4]=> string(21) " 2016-06-05 01:02:1 " }