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pH estimation of fetal scalp blood using magnetic induction spectroscopy technique
No full textMaster of Science in Biomedical Electronic EngineeringThis thesis describes the development of fetal scalp pH estimation utilizing magnetic induction spectroscopy technique. Magnetic induction spectroscopy is a non-invasive approach that applies a magnetic field to determine the passive electrical properties. The
relationship of the induced signal at the receiver and fetal scalp pH value was investigated. COMSOL Multiphysics® software was used to simulated sensor probe design. The simulation was done with several parameters such as frequency range, sensor geometry, number of turns and distance between transmitter and receiver coil to determine the suitable single channel magnetic induction spectroscopy technique for fetal scalp pH measurement design. The best result from parameters simulation was combined and finalized to be final sensor design. Then, the hardware was develop according to the simulation result. Mathematical equation was derived to show the relationship between voltage and pH. The result shows that the magnetic induction spectroscopy was capable to detect pH changes in the fetal scalp blood mimic model. The frequency range must be
in the range of MegaHertz to increase the production of induced field. Circular coil was choose as the most suitable sensor geometry due to its sensitivity to detect smallest hydrogen conductivity changes in fetal scalp blood mimic model. The distance between the sensing coils of 0.08 mm was better than 0.1 mm because the strength of the field decreases with increasing distance from the wire. The error percentage acquired from prediction mathematical equation was less than 1% and the correlation obtained between
the induced signal and pH was greater than 0.9190
OFDM system based on framelet transform and radon mapping with FPGA implementation
No full textDoctor of Philosophy in Communication EngineeringIncreasing demands for high speed data transmission and unrivalled spectral efficiency are drivers for the current and future wireless communication systems. Orthogonal Frequency Division Multiplexing (OFDM) has been recognized as one of the most
promising techniques for supporting high data rate transmission due to its promising attributes. Nonetheless, and despite all the advantages of this technique, OFDM signal suffers from the fading implications of the wireless channels that cause even more Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI). Therefore, Cyclic Prefix (CP) is employed in the traditional OFDM to entirely eradicate ISI/ICI, but this approach affects the transmission efficiency by losing about 25% of the available
bandwidth. Therefore, a novel OFDM system based on a new combination between
Framelet Transform (FT) and Finite Radon mapping (FRAT) is proposed in this thesis
in order to enhance the immunity of OFDM system against the detrimental effects of
multipath fading and increasing its ability to eradicate the ISI and ICI in the presence of
a simple equalizer without the necessity for CP. The proposed system, called N-FRATFT-
OFDM, was simulated and compared to other OFDM systems, such as FFT-based
OFDM using N-FRAT mapping (N-FRAT-FFT-OFDM), FT-based OFDM using QAM
mapping (QAM-FT-OFDM), and FFT-based OFDM using QAM mapping (QAM-FFTOFDM).
The simulation was conducted for various constellation points over different
channel conditions and parameters using MATLAB software. The results showed that
the new structure outperformed the other three systems by reducing ISI/ICI, which then
improved the performance of the Bit Error Rate (BER). For instance, in the frequency
selective fading channel and maximum Doppler frequency (fd =100 Hz) with 4-FRAT
mapping, which is equivalent to 16-QAM mapping, 4-FRAT-FT-OFDM reported 12.35
dB and 19.35 dB gain in the Energy per bit to Noise power spectral density ratio
(Eb/No) measured at BER = 10-3 compared with 4-FRAT-FFT-OFDM and 16-QAMFFT-
OFDM, respectively, while the 16-QAM-FT-OFDM system washout to attain such
BER. Moreover, Alamouti Space-Time Block Code (STBC) was proposed in the
structure of N-FRAT-FT-OFDM system to further enhance BER performance at high
data rates and increase bandwidth efficiency by increasing the spatial diversity of the
system. A proposed system is equipped with two different approaches of STBC: the
first is STBC-based N-FRAT-FT-OFDM (STBC-N-FRAT-FT-OFDM), with two
transmitter antennas and one receiver antenna (2Tx-1Rx), while the second is STBC-NFRAT-
FT-OFDM, with two transmitters and two receiver antennas (2Tx-2Rx)
