Title :
Analysis and optimization of pilot-symbol-assisted-modulation M-QAM for OFDM systems
Author :
Chen, Jiming ; Tang, Youxi ; Li, Shaoqian
Author_Institution :
Nat. Key Lab. of Commun., Univ. of Electron. Sci. & Technol. of China, Chengdu, China
Abstract :
In this paper, the current analysis focuses on the influence of demodulation performance in multipath fading propagation environments, which results from the pilot power variation of pilot symbol assisted modulation (PSAM) M-QAM in orthogonal frequency division multiplexing (OFDM) systems. The pilot-to-data power ratio (PDR) is optimized analytically, the loss due to imperfect channel estimation is calculated, and the probability is presented. Theoretical and simulation results show that the optimum PDR is affected by the signal-to-noise ratio (SNR), Doppler frequency and interpolation size etc. When the optimization parameter of PDR is used, the power of system transmission is minimum while still meeting a fixed bit error rate (BER) target, meanwhile the system can obtain to accurate channel estimation.
Keywords :
Doppler effect; OFDM modulation; channel estimation; demodulation; error statistics; fading channels; interpolation; mobile radio; multipath channels; optimisation; quadrature amplitude modulation; BER; Doppler frequency; M-QAM; OFDM system; PDR; PSAM; bit error rate; channel estimation; demodulation performance; interpolation; multipath fading propagation environment; optimization parameter; orthogonal frequency division multiplexing; pilot symbol assisted modulation; pilot-to-data power ratio; quadrature amplitude modulation; Bit error rate; Channel estimation; Data communication; Demodulation; Fading; Multiaccess communication; Numerical analysis; OFDM modulation; Performance analysis; Signal to noise ratio;
Conference_Titel :
Vehicular Technology Conference, 2003. VTC 2003-Fall. 2003 IEEE 58th
Print_ISBN :
0-7803-7954-3
DOI :
10.1109/VETECF.2003.1285974
