Title :
Hardware implementation of a differential QAM modem
Author :
Koukourlis, Christos S.
Author_Institution :
Telecommun. Syst. Lab., Demokritos Univ. of Thrace, Xanthi, Greece
fDate :
9/1/1997 12:00:00 AM
Abstract :
A QAM modem based on certain modifications of the CCITT Recommendation V.29, is presented. A predominantly digital implementation without the use of DSP devices is given. Although the implementation is for telephone bandwidth the idea can be expanded to achieve higher rates. In this design approach the modulation is based on ROM-stored symbols while the demodulation is based on a symbol-by-symbol determination for the recovery of the original information bits. Specifically, the paper refers to a D16QAM design. Most of the stages are digital, a feature that simplifies the VLSI implementation. The synchronisation (timing recovery) is based on a modified phase locked loop
Keywords :
VLSI; demodulation; digital integrated circuits; digital phase locked loops; modems; quadrature amplitude modulation; read-only storage; synchronisation; CCITT Recommendation V.29; D16QAM design; PLL; ROM stored symbols; VLSI implementation; demodulation; differential QAM modem; digital implementation; hardware implementation; modified phase locked loop; modulation; original information bits recovery; symbol by symbol determination; synchronisation; telephone bandwidth; timing recovery; Bandwidth; Demodulation; Digital signal processing; Hardware; Modems; Phase locked loops; Quadrature amplitude modulation; Telephony; Timing; Very large scale integration;
Journal_Title :
Broadcasting, IEEE Transactions on
