Dynamic Bit Loading with the OGFDM Waveform Maximises Bit-Rate of Future Mobile Communications

Abstract

A new Dynamic Bit Loading (DBL) scheme with the Orthogonal Generalized Frequency Division Multiplexing (OGFDM) is, for the first time, proposed, discussed and assessed. The key concept of this hybrid modulation format depends substantially on the adaptive distribution of the bit stream to be more compatible with the gained capacity of the realistic channel state. Due to the negative impact of employing the fixed schemes of digital modulation on the performance of the conventional telecommunications systems, the influence of using the multi-level modulation system is investigated for the future applications of mobile communications. Utilising the DBL in the physical layer (PHY), a flexible range of modulation formats can be optimally assigned for each applied frequency sub-carrier in accordance with wireless channel circumstances. In addition, depending on the supportive features of the proposed modulation system, the performance in terms of channel capacity can be maximised at the acceptable limit of the Bit Error Rate (BER). As such, an extra enhancement can be achieved in the spectrum efficiency (SE) of the adaptively modulated wireless signal. Thus, an adjustable boost of the transmission range of used modulation formats can be reached with the introduced adaptation system. The performance of the DBL system through a wireless mobile channel under the Additive White Gaussian Noise (AWGN) is evaluated according to a various level of the Signal to Noise Ratio (SNR). Ultimately, regarding the numerical simulation, a MATLAB code is employed to simulate the performance (channel capacity & BER) of the proposed DBL that is fundamentally accommodated by the recent candidate waveform of future mobile technology (OGFDM).