Pseudobinary and Pseudoquaternary Detection Processes for Linearly Distorted Multilevel QAM Signals

• Published in: IEEE transactions on communications Vol. 33; no. 7; pp. 639 - 645
• Main Authors: Clark, A., Abdullah, S., Jayasinghe, S., Keung Sun
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.07.1985; Institute of Electrical and Electronics Engineers
• Subjects: Additive white noise; Applied sciences; Circuit testing; Computer simulation; Data communication; Detectors; Distortion; Exact sciences and technology; Information, signal and communications theory; Intersymbol interference; Modulation, demodulation; Quadrature amplitude modulation; Signal and communications theory; Signal processing; System testing; Telecommunications and information theory; Serial transmission; Intersymbol interference; Electromagnetic interference; Test; Synchronous transmission; Data transmission; Distortion; Amplitude modulation; Quadrature modulation; Pulse modulation; Signal detection
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOM.1985.1096351

The paper describes two new detection processes suitable for QAM signals that have 16 or more levels (possible data symbol values) and that have been subjected to linear distortion, causing severe intersymbol interference in the received signal. The detectors are developments of the pseudobinary systems previously described, and are designed to operate in the presence of severe intersymbol interference. Results of computer simulation tests are presented, comparing the tolerances to additive white Gaussian noise of various arrangements of each detector with those of more conventional detectors. The tests have been carried out on a model of a 19 200 bit/s synchronous serial data transmission system, operating with a 64-level QAM signal that is transmitted, in turn, over two different telephone circuits.