Volume 13, Number 5

Dual-carrier Modulation of COFDM with Labeling Diversity to Reduce PAPR


Allen Le Roy Limberg


Dual-carrier modulation (DCM) is used to implement a species of tone reservation to reduce the PAPR of COFDM, wherein the reserved tones convey coded digital data (CDD) a second time. The same CDD is conveyed by carriers in a lower-frequency sub-band of the COFDM and by carriers in a higher- frequency sub-band. Each pair of carriers conveying the same CDD are separated by a subband width, enabling receivers better to ameliorate the effects of multipath reception. There is labeling diversity between the QAM symbol constellations that respectively govern modulation of carriers in the lower- frequency sub-band and modulation of carriers in the higher-frequency subband, which labeling diversity is designed to reduce PAPR of the COFDM. The labeling diversity also improves bit-error ratio (BER) for increased-size QAM symbol constellations used to increase CDD throughput despite the halving of CDD throughput owing to the use of DCM.


OFDM modulation, Peak-to -average power ratio, Dual carrier modulation,Labeling Diversity, QAM symbol constellation mapping.