Power Allocation for Frequency-Modulated OFDM Wireless Systems

Frequency-modulated orthogonal frequency division multiplexing (FM-OFDM) is a recently proposed waveform which overcomes the notoriously high peak-to-average power ratio (PAPR) of traditional OFDM wireless systems. Employing this new FM-OFDM waveform, however, will demand a redesign of certain signal processing mechanisms, since those tailored to traditional OFDM waveforms may no longer be optimal or even applicable. This paper proposes two novel power allocation schemes for FM-OFDM systems, both of which take into account this new waveform's unique interactions with noise and with the propagation channel. We analytically derive and optimize closed-form expressions for both of the proposed power allocation schemes, the first of which improves average bit error rate (BER) while the second maximizes spectral efficiency. Our simulation results illustrate the improvements in BER and in data rate when employing our power allocation schemes over conventional benchmarks but also underscore what regimes they should be employed to maximize these gains.