Title :
Adaptive OFDM for wideband radio channels
Author :
Czylwik, Andreas
Author_Institution :
Res. Center, Deutsche Telekom AG, Darmstadt, Germany
Abstract :
An OFDM (orthogonal frequency division multiplexing) transmission system is simulated with time-variant transfer functions measured with a wideband channel sounder. The individual subcarriers are modulated with fixed and adaptive signal alphabets. Furthermore, a frequency-independent as well as the optimum power distribution are used. The simulations show that with adaptive OFDM, the required signal power for an error probability of 10-3 can be reduced by 5…15 dB compared with fixed OFDM. The fraction of channel capacity which can be achieved with adaptive OFDM depends on the average signal-to-noise ratio and the propagation scenario
Keywords :
adaptive systems; broadband networks; channel capacity; frequency division multiplexing; modulation; radio networks; subcarrier multiplexing; transfer functions; 1.8 GHz; adaptive OFDM; channel capacity; error probability; optimum power distribution; orthogonal frequency division multiplexing; propagation scenario; required signal power; signal alphabets; subcarriers; time-variant transfer functions; transmission system; wideband channel sounder; wideband radio channels; AWGN; Additive white noise; Bandwidth; Channel capacity; Error probability; Frequency measurement; OFDM modulation; Signal to noise ratio; Transfer functions; Wideband;
Conference_Titel :
Global Telecommunications Conference, 1996. GLOBECOM '96. 'Communications: The Key to Global Prosperity
Conference_Location :
London
Print_ISBN :
0-7803-3336-5
DOI :
10.1109/GLOCOM.1996.594454
