Title :
OFDM for data communication over mobile radio FM channels. I. Analysis and experimental results
Author :
Casas, Eduardo F. ; Leung, Cyril
Author_Institution :
Dept. of Electr. Eng., British Columbia Univ., Vancouver, BC, Canada
fDate :
5/1/1991 12:00:00 AM
Abstract :
The performance of OFDM/FM modulation for digital communication over Rayleigh-fading mobile radio channels is described. The use of orthogonal frequency division multiplexing (OFDM) over mobile radio channels was proposed by Cimini (1985). OFDM transmits blocks of bits in parallel and reduces the bit error rate (BER) by averaging the effects of fading over the bits in the block. OFDM/FM is a modulation technique in which the OFDM baseband signal is used to modulate an FM transmitter. OFDM/FM can be implemented simply and inexpensively by retrofitting existing FM communication systems. Expressions are derived for the BER and word error rate (WER) within a block when each subchannel is QAM-modulated. Several numerical methods are developed to evaluate the overall BER and WER. An experimental OFDM/FM system was implemented and tested using unmodified VHF FM radio equipment and a fading channel simulator. The BER and WER results obtained from the hardware measurements agree closely with the numerical results
Keywords :
data communication systems; digital radio systems; fading; frequency division multiplexing; frequency modulation; mobile radio systems; telecommunication channels; BER; FM communication systems; FM transmitter; OFDM/FM modulation; QAM-modulated; Rayleigh-fading; VHF FM radio equipment; baseband signal; bit error rate; data communication; digital communication; experimental results; fading channel simulator; hardware measurements; mobile radio FM channels; numerical methods; orthogonal frequency division multiplexing; word error rate; Baseband; Bit error rate; Data communication; Digital communication; Digital modulation; Fading; Frequency modulation; Land mobile radio; OFDM modulation; Rayleigh channels;
Journal_Title :
Communications, IEEE Transactions on
