Digital Chunk Processing with Orthogonal GFDM Doubles Wireless Channel Capacity

A novel physical layer (PHY) transmission technique for increasing the channel capacity of transmission, termed as Orthogonal Generalized Frequency Division Multiplexing (OGFDM), has been proposed, investigated and evaluated in this paper. A combination of the Digital Hilbert Filter (DHF) with Generalized Frequency Division Multiplexing (GFDM) has been shown to double wireless channel capacity for each transmitted frequency sub-carrier at acceptable Bit Error Rate (BER) limits. By making use of the great properties of Hilbert transforms, orthogonality is achieved between the traditionally non-orthogonal GDFM subcarriers improving the BER and wireless channel capacity of the transmission. The OGFDM seems to combine the attributes of GFDM and Orthogonal Frequency Division Multiplexing (OFDM) in one sustainable system. The proposed solution achieves orthogonality between the filters of adjacent frequencies of subcarriers instead of between the frequencies of subcarriers themselves. Also, an OGFDM system model is presented, based on which, the relation between the main filter parameters and the system BER and channel capacity performance is specified in a wireless electrical back-to-back transmission system. Finally, by means of simulations, the impact of applying the proposed advanced filters on the aggregated system performance of the BER and channel capacity is shown in an Additive White Gaussian Noise (AWGN) wireless channel

Orthogonal Generalized Frequency Division Multiplexing (OGFDM)

This thesis focuses on introducing a novel technique of the transmission waveform termed as orthogonal generalized frequency division multiplexing (OGFDM) for increasing the wireless channel capacity without the need for extra bandwidth (BW) size or power consumption. The new wireless waveform (OGFDM) tends to obtain a better BW efficiency which in turn can increase highly the wireless channel capacity in comparison with the generalized frequency division multiplexing (GFDM) and cyclic-prefix orthogonal frequency division multiplexing (CP-OFDM). The main feature of the OGFDM is developing the physical layer of future mobile networks by achieving the orthogonality between non-orthogonal filters, removing the interference between adjacent frequency subcarriers, and gaining a flexible bit loading scheme. Since the key downsides of the 4G waveform (CP-OFDM), several alternative transmission waveforms have been investigated for improving transmission techniques of the upcoming communication networks (5G and beyond). This, as a result, comes up with introducing the GFDM as the best candidate waveform for the 5G air interface. Nevertheless, due to ignoring the orthogonality with the GFDM, the BW efficiency is severely affected which in turn causes in extremely reducing the gained channel capacity (research gap). For this reason, the proposed OGFDM waveform aims to improve wireless channel capacity by investigating different levels of processing and carrier schemes. As such, three key levels called as filtration level, oversampling level, and modulation level are adopted for a variant range of OGFDM carriers like a single carrier, couple carrier, quadruple carrier, and multi-carrier system. Regarding the single carrier OGFDM system where the filtration level is developed, the orthogonality is attained between the non-orthogonal filters of the GFDM frequency subcarriers. The core idea behind this novel technique is increasing the efficiency of the applied BW which in turn can double the capacity of the channel at the acceptable level of the bit error rate (BER). Concerning the couple carrier OGFDM system where the oversampling level is developed, the double oversampling mode is applied side by side with the normal one. As a result, the OGFDM waveform can efficiently avoid the interference between adjacent frequency subcarriers improving the quality of service under bad transmission states. As regards the quadruple carrier OGFDM system where the modulation level is improved, a flexible modulation scheme is utilized rather than the fixed modulation formats. Consequently, multilevel modulation shapes are optimally assigned to gain an enhanced channel capacity in accordance with the realistic transmission state. To achieve a higher BW efficiency, the preliminary multi-carrier system that combines the three levels of processing in one uniformed physical platform is introduced. To demonstrate the main advantages of OGFDM waveform, the multicarrier system is further extended and compared with the GFDM (5G technology) and CP-OFDM (LTE Ericsson technology). Hence, the multi-carrier OGFDM can double, boost, and yet maximize the bit-rate of the transmission relative to the GFDM and CP-OFDM at the acceptable level of the BER. The MATLAB simulation and Visio tools are utilized to validate the results and represent them graphically