Title :
Implementation of a 64-QAM modem for 140 Mbit/s digital radio
Author :
Bolla, M. ; Rossi, L. ; Verbana, G.
Author_Institution :
TELETTRA SpA, Vimercate, Italy
Abstract :
The authors describe a newly developed 64-QAM (quadrature amplitude modulation) modem for use in microwave terrestrial radio systems at 140 Mbit/s. Digital signal processing and LSI technology are extensively used in the implementation of several modem functions to ensure compactness, high reliability, and low power consumption in the equipment. In particular, a seven-tap baseband digital equalizer (BDE) is employed to counteract multipath fading, and forward error correction (FEC) is adopted to eliminate residual bit errors caused by modem imperfections. Finally, BDE and FEC are jointly exploited to provide monitoring capability in early error detection and protection switching
Keywords :
amplitude modulation; digital radio systems; error correction; error detection; microwave links; modems; 140 Mbit/s; 64-QAM modem; DSP; FEC; LSI technology; digital signal processing; error detection; forward error correction; low power consumption; microwave terrestrial radio systems; multipath fading; protection switching; quadrature amplitude modulation; reliability; seven-tap baseband digital equalizer; Baseband; Digital communication; Digital signal processing; Energy consumption; Forward error correction; Large scale integration; Microwave devices; Modems; Power system reliability; Quadrature amplitude modulation;
Conference_Titel :
Communications, 1991. ICC '91, Conference Record. IEEE International Conference on
Conference_Location :
Denver, CO
Print_ISBN :
0-7803-0006-8
DOI :
10.1109/ICC.1991.162350
