Mobile QR Code QR CODE : The Transactions of the Korean Institute of Electrical Engineers
Title A Rotational Decision-Directed Joint Algorithm of Blind Equalization Coupled with Carrier Recovery for 32-QAM Demodulation
Authors 송진호(Song, Jin-Ho) ; 황유모(Hwang, Hu-Mor)
Page pp.78-85
ISSN 1975-8359
Keywords Blind equalization ; Carrier recovery ; RDDCR ; RDDBE ; Joint algorithm
Abstract We introduce a rotational decision-directed joint algorithm of blind equalization coupled with carrier recovery for 32-QAM demodulation with high symbol rate. The proposed carrier recovery, which we call a rotational decision-directed carrier recovery(RDDCR), removes the residual phase difference by rotating the decision boundary for the kth received symbol by the frequency detector output of the (k-1)th received symbol. Since the RDDCR includes the function of PLL loop filter by rotating the decision boundary, it gives a simpler demodulator structure. The rotational decision-directed blind equalization(RDDBE) with the rotated decision boundary based on the Stop-and-Go Algorithm(SGA) operated during tracking the frequency offset by the RDDCR and removes intersymbol interference due to multipaths and channel noise. Test results show that symbol error rate of 10^{-3} is obtained before the forward error correction when SNR equals 15dB with 150KHz of carrier frequency offset and two multipaths, which is the channel condition for 32-QAM receiver.