Title :
Adaptive modulation with limited peak power for fading channels
Author :
Choi, Won-Joon ; Cheong, Kok-Wui ; Cioffi, John M.
Author_Institution :
Space, Telecommun. & Radiosci. Lab., Stanford Univ., CA, USA
Abstract :
This paper investigates the problem of maximizing the spectral efficiency for adaptive modulated systems with a peak power constraint. The solutions for both the continuous constellation case and the discrete constellation case are derived by the Lagrangian method,and an iterative algorithm solving the Karush-Kuhn-Tucker (KKT) optimality conditions are proposed. Our simulation results show that the spectral efficiency loss due to the peak power constraint is small and the target bit error rate (BER) can be guaranteed by our algorithm. In particular, the spectral efficiency loss remains within 1 [bps/Hz] for the continuous constellation case and 2 [bps/Hz] for the discrete constellation case at average signal-to-noise ratio (SNR) of 20 dB
Keywords :
Rayleigh channels; adaptive modulation; channel capacity; error statistics; iterative methods; noise; optimisation; quadrature amplitude modulation; BER; Karush-Kuhn-Tucker optimality conditions; Lagrangian method; QAM; Rayleigh fading; SNR; adaptive modulation; average signal-to-noise ratio; bit error rate; channel capacity; continuous constellation; discrete constellation; fading channels; high speed wireless digital communications; iterative algorithm; limited peak power; peak power constraint; simulation results; spectral efficiency loss; spectral efficiency maximisation; Bit error rate; Constellation diagram; Fading; Interference; Iterative algorithms; Laboratories; Power amplifiers; Power system modeling; Transmitters; Wireless communication;
Conference_Titel :
Vehicular Technology Conference Proceedings, 2000. VTC 2000-Spring Tokyo. 2000 IEEE 51st
Conference_Location :
Tokyo
Print_ISBN :
0-7803-5718-3
DOI :
10.1109/VETECS.2000.851737
