Performance Improvement for Maximizing Capacity of Crowded Spectrum using Advanced Modulation and Coding Techniques

Authors: Udo, E.U., Iro-David, J. And Odo, K.O.

DOI Info: http://doi.org/10.5281/zenodo.8094634

ABSTRACT

The requirement of data transfer poses a big threat because of numerous challenges such as adjacent and co-channel interference problems, spectral congestion and noise corrupted data reception. These challenges require the development of new encoding, modulation, demodulation and decoding techniques for newer transmission channels. This is the motivation for the current work. The method employed the development of orthogonal frequency division multiplexing (OFDM) models with space time block code (STBC) and without space time block code. The performance of bit-error-rate (BER) and signal-to-noise ratio (SNR) was obtained using Matlab/Simulink. The results of the simulation showed that the highest value for BER with STBC was 8x10^-1 and highest value for BER without STBC was 9x10^-5. The highest value for SNR with STBC and the highest value for SNR without STBC were 21.78 dB and 10.84 dB while the lowest value for SNR with STBC and the lowest value for SNR without STBC were 22.23 dB and 0 dB respectively. Again, when SNR was 5 dB, the BER (X10^-4) for Binary Phase Shift Keying, Quadrature Phase Shift Keying, 8-Quadrature Amplitude Modulation, 16- Quadrature Amplitude Modulation and 64- Quadrature Amplitude Modulation was 40, 20, 4, 10 and 30 and when SNR was 10 dB, the BER(X10^-4) was 4, 2, 0.4, 1 and 3. However, it was observed that OFDM model with STBC produces better performance than OFDM model without STBC. This indicated that the bit-error-rate decreases with an increase in signal-to-noise ratio and also improve the quality of service of the crowded spectrum.

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