DocumentCode :
1062149
Title :
256 QAM Modem for Multicarrier 400 Mbit/s Digital Radio
Author :
Nakamura, Yasuhisa ; Saito, Yoichi ; Aikawa, Satoru
Author_Institution :
Nippon Telegraph and Telephone Corp., Kanagawa, Japan
Volume :
5
Issue :
3
fYear :
1987
fDate :
4/1/1987 12:00:00 AM
Firstpage :
329
Lastpage :
335
Abstract :
This paper describes the performance of a 256 QAM modem with 400 Mbit / s transmission capacity. A variety of novel techniques are introduced as ways to achieve good performance. Key techniques include 1) an accurate 256 QAM modulator employing a new monolithic multiplier IC, 2) a carrier recovery circuit which satisfies such requirements: good phase jitter performance and no false lock phenomenon, 3) a highly stable high-level decision circuit, and 4) a forward error correcting code. As an overall modem performance, BER characteristics and signatures are presented. The equivalent CNR degradations of 1 dB(at BER of 10-4) and 2 dB (at BER of 10-9)are obtained using a single Lee-error correcting code and a seven-tap baseband transversal equalizer. The residual bit errors are decreased below the order of 10-10. The performance of a 256 QAM multicarrier modem has given prospect for the development of 400 Mbit/s digital microwave radio system.
Keywords :
Digital modulation/demodulation; Quadrature amplitude modulation; Bit error rate; Degradation; Digital communication; Error correction codes; Jitter; Modems; Modulation coding; Monolithic integrated circuits; Phase modulation; Quadrature amplitude modulation;
fLanguage :
English
Journal_Title :
Selected Areas in Communications, IEEE Journal on
Publisher :
ieee
ISSN :
0733-8716
Type :
jour
DOI :
10.1109/JSAC.1987.1146555
Filename :
1146555
Link To Document :
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