Title :
16 QAM modulation with orthogonal frequency division multiplexing in a Rayleigh-fading environment
Author :
Wilson, Sarah Kate ; Khayata, Ellen R. ; Cioffi, John M.
Author_Institution :
Inf. Syst. Lab., Stanford Univ., CA, USA
Abstract :
We introduce a method for tracking a Rayleigh-fading channel with Orthogonal Frequency Division multiplexing (OFDM) so that multi-amplitude bit rate schemes such as 16 QAM may be used in a wireless channel. In addition, we derive a distribution to predict the symbol error rate of the modulation scheme. The modulation scheme is applied to an indoor wireless system operating at a rate of 25 Mb/s. The probability of error derived from simulation shows good agreement with the theoretically predicted probability of error. We keep a fairly large bit rate by using few training symbols; in simulation, the error propagation accounts for a slight increase in symbol error rate, but is not catastrophic due to the use of rotationally-invariant 16 QAM constellations
Keywords :
Rayleigh channels; autoregressive processes; digital radio; diversity reception; error statistics; fading; frequency division multiplexing; indoor radio; land mobile radio; quadrature amplitude modulation; 16 QAM modulation; 25 Mbit/s; OFDM; Rayleigh-fading environment; error probability; error propagation; indoor wireless system; modulation scheme; multi-amplitude bit rate schemes; orthogonal frequency division multiplexing; rotationally-invariant 16 QAM constellations; simulation; symbol error rate; training symbols; wireless channel; Bit rate; Digital audio broadcasting; Error analysis; Fading; Frequency modulation; Intersymbol interference; OFDM modulation; Phase estimation; Quadrature amplitude modulation; Rayleigh channels;
Conference_Titel :
Vehicular Technology Conference, 1994 IEEE 44th
Conference_Location :
Stockholm
Print_ISBN :
0-7803-1927-3
DOI :
10.1109/VETEC.1994.345378
