Title :
Synchronization of turbo coded modulation systems at low SNR
Author :
Lu, Lijun ; Wilson, Stephen G.
Author_Institution :
Dept. of Electr. Eng., Virginia Univ., Charlottesville, VA, USA
Abstract :
This paper examines the synchronization of turbo coded modulation systems at low SNR where these systems are designed to operate. Maximum likelihood estimation theory is used to derive a causal, discrete-time synchronization structure for estimating the carrier phase and symbol timing of a general QAM signal, using a decision-directed structure which is known to be superior at low SNR. Simulation shows that efficient joint carrier phase and symbol timing estimates can be acquired using our synchronizer for turbo codes. Bit error performance for selected loop bandwidths is presented
Keywords :
concatenated codes; convolutional codes; digital phase locked loops; error statistics; maximum likelihood estimation; modulation coding; phase estimation; quadrature amplitude modulation; synchronisation; QAM signal; bit error performance; carrier phase estimation; causal discrete-time synchronization structure; decision-directed structure; digital phase locked loop; low SNR; maximum likelihood estimation theory; symbol timing estimation; turbo coded modulation systems; turbo codes; Frequency estimation; Frequency synchronization; Matched filters; Maximum likelihood estimation; Modulation coding; Phase estimation; Quadrature amplitude modulation; Quadrature phase shift keying; Timing; Turbo codes;
Conference_Titel :
Communications, 1998. ICC 98. Conference Record. 1998 IEEE International Conference on
Conference_Location :
Atlanta, GA
Print_ISBN :
0-7803-4788-9
DOI :
10.1109/ICC.1998.682888
