New method of polar channel coding for reducing the bit error rate with low complexity in the F-OFDM underwater acoustic communications

Underwater Acoustic (UWA) communication system plays a crucial role in various applications and contributes significant performance in comparison to other communication systems. UWA is essential in various applications such as oceanographic, oil exploration, military applications etc. However, it is characterized by a high Bit Error Rate (BER), the main obstacle of the UWA system in real applications because the sound waves are subjected to Underwater Acoustic Noise (UWAN), which is either manmade or natural. Channel coding is one of the effective BER reduction techniques that has been employed for reducing the BER. Nonetheless, high computational complexity is the main drawback of this technique. This thesis studies the UWAN in the shallow waters of tropical seas as a field data which have a significant impulsive behaviour. The analysis of the field data showed that the UWAN does not satisfy the assumption of Gaussian noise, it nonetheless fits well to t-distribution with three degrees of freedom. Also, the derivation of Binary Phase Shift Keying (BPSK) and Quadrature Phase Shift Keying (QPSK) for the UWA was proposed and validated with the channel simulation. In addition, this thesis proposes a new method in UWA for reducing the BER value with low computational complexity. The proposed method has been applied to Orthogonal Frequency Division Multiplexing (OFDM) and Filtered-OFDM (F-OFDM) systems through MATLAB software simulation, where F-OFDM refers to the waveform design candidate in the new technology. The efficiency of the proposed method is verified by comparing the results with the existing channel coding in the literature using MATLAB software simulation. The results obtained using the proposed method and turbo code achieved a superior gain in the signal-noise ratio (SNR) about 11.2 dB and 13.5 dB respectively at BER of 1×10-3 compared to the uncoded (without channel coding). In addition, the computational complexity levels have been reduced about 84% and 68% for the information block length (k) of 256 and 1024 respectively. In conclusion, The F-OFDM shows a better as compared to OFDM.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

Universiti Tun Hussein Onn Malaysia

Year dc:date.issued

2020

Author dc:creator

• Ahmed, Mustafa Sami

• TK5101-6720 Telecommunication. Including telegraphy, telephone, radio, radar, television

Language dc:language

en