Title :
Convergence time improvement in the carrier recovery circuits for digital QAM radio link
Author :
Bernardini, Andrea ; Fina, S. De ; Parente, P.
Author_Institution :
INFOCOM Dept., Rome Univ., Italy
Abstract :
The performance of a particular baseband circuit for carrier recovery (CR) in QAM (quadrature amplitude modulation) digital radio links is analyzed. An increase of convergence speed is made possible by adopting conventional phase detectors through the use not only of the diagonal QAM signal states, but also of the all-QAM signal states. Use of this technique makes blind convergence possible. S-curves are plotted for the analysis of algorithm performances. A differential modulation method should also be implemented in order to recover the phase errors greater than π/2. It is suggested that an optimum subset of QAM signal states be investigated to find an optimum compromise between convergence speed and performance
Keywords :
amplitude modulation; carrier communication; convergence; digital radio systems; radio links; S-curves; algorithm performances; all-QAM signal states; blind convergence; carrier recovery circuits; convergence speed; convergence time improvement; diagonal QAM signal states; differential modulation method; digital QAM radio link; phase detectors; phase error recovery; quadrature amplitude modulation; Algorithm design and analysis; Baseband; Chromium; Circuits; Convergence; Detectors; Digital communication; Performance analysis; Phase detection; Quadrature amplitude modulation;
Conference_Titel :
Global Telecommunications Conference and Exhibition 'Communications Technology for the 1990s and Beyond' (GLOBECOM), 1989. IEEE
Conference_Location :
Dallas, TX
DOI :
10.1109/GLOCOM.1989.64002
