Institute of Technology

Permanent URI for this communityhttps://etd.hu.edu.et/handle/123456789/66

The Institute of Technology focuses on education, research, and innovation in engineering, technology, and applied sciences to support sustainable development.

Browse

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    ANALYSIS AND MODELING OF 5G NETWORK PERFORMANCE BASED ON RESPONSE TIME REDUCTION
    (Hawassa University, 2023-11) MEKASHA MEKURIA
    Despite the fact that 5G technology has the benefits of meeting all of the key requirements for a 5G system and understanding the secrets for attaining a reduced response time, which was the most dominating component in 5G, the globe had adequate bandwidth in earlier generations for daily usage. However, response time was not a major concern, but for today's applications such as VANET and ongoing online gaming, as well as for vertical industries accessibilities such as SDN (software-defined network), NFV (network function virtualization), URLLC (ultra-reliable low latency communication), backhaul connection, and control or location update information, response time is more crucial than output. To address the aforementioned challenges and gaps, the study have analyzed the numerologies to 5G NR(radio network) recognizing KPI for cellular system analysis based on human demands and technological efforts to fulfil purpose, and address the aforementioned challenges by using the 5G toolbox for techniques of simulating hidden 5G numerologies. The simulation results show that our proposed approach outperforms state-of-the-art techniques because it yields the highest probability in regarding the requirements from the access network in response time reduction. As a practical implication of the study, the researcher have realized that the adaptable subframe structure leads to a very low symbol duration, which enables low response time, as time critical applications increased, and that wider subcarrier spacing could be used for users to provide them with very low response time symbol duration. In the future work, the study planned to incorporate the channel modeling of the mmwave band was relatively complex; which does not have any perfect channel model, high capacity backhaul connectivity, for its challenging for the exponentially growing data demands of 5G and would be required more additional exploration in depth and spectrum and interference management due to the scarcity of the spectrum resources and interference issues, thus needs efficiently manage the 5G spectrum, hence should be to conduct comparative performance analysis.
  • No Thumbnail Available
    Item
    Comparative Performance Analysis of Channel Estimation Techniques for Massive MIMO System
    (Hawassa University, 2021-12-17) Ashenafi Gebre
    The need for an internet connection is growing universally, so people need much higher data rate connection to meet their need but every physical resource in communication like frequency band, transmit signal strength are finite. Within the given limited resource, higher data speed is accomplished by a new technology called massive Multiple Input Multiple Output (massive MIMO) system. Massive MIMO fulfills the high data rate requirement through antenna diversity gain. It is one of 5G wireless network technology with array antennas at both transmitter and receiver sides to providing high spectral and energy efficiencies. In massive MIMO, the signal obtained by the receiver is in different phase and amplitude from the transmission signal. Therefore, the system quality is highly depending on the accuracy of the channel estimation. Channel estimation plays a significant role in the performances of massive MIMO system because the dimension of the channels matrix is large, phase changes and noises are added when the signals pass through channel, these reduces the efficiencies of the whole system. To solve these problems, this Thesis focuses on the comparative analysis of pilot-based channel estimation schemes for massive MIMO system, which includes: Minimum Mean square Error (MMSE), Element Wise Minimum Mean Square Error (EW-MMSE), Maximum Likelihood (ML) and Least Square (LS) estimator with respect to Normalized Mean square Error (NMSE), Signal to Noise Ratio (SNR), Spectral Efficiency (SE), number of BS antennas, and number of computational complexities. Based on the simulation results, MMSE channel estimator has the best performance, followed by EW-MMSE, ML and LS channel estimators in terms of NMSE and SNR. And depending on the number of computational complexities of each coherent block as a function of BS antennas M with constant UE, the complexity of LS is less than that of MMSE, and it has almost the same complexity as ML and EW-MMSE. And also, according to SE with respect to BS antenna M, the MMSE provides the highest SE using the highest complexity, EW-MMSE and ML achieves a good balance between SE and complexity, and LS has the lowest complexity, but also provides the lowest SE. Finally, the result confirms that MMSE channel estimation technique has the best performance compared to EW-MMSE, ML and LS channel estimators with the cost of high complexity
  • No Thumbnail Available
    Item
    Performance Analysis of Modulation Techniques for 5G Networks
    (Hawassa University, 2018-03-17) GETACHEW HAGOS
    The new 5G cellular network systems will feature several innovative strategies as compared to existing LTE systems, such as extensive adoption of small cells, use of mm-wave communications for short-range links, large scale antenna arrays installed on macro base stations, cloud-based radio access network, cognitive radio etc. All these strategies will be impacted by the modulation format used at the physical layer. At the same time, 5G cellular networks will have more stringent requirements than LTE in terms of latency, energy efficiency and data rates, which again are impacted by the adopted modulation scheme. Hence, proper selection and utilizing efficient modulation scheme is critical. The current modulation technique such as orthogonal frequency division multiplexing (OFDM) suffers from high peak to average power ratio which results in low efficiency of power amplifier and increases the battery consumption. Moreover, the OFDM spectrum has high out of band side lobes or side lobe leakage causing problem of low spectral efficiency. Therefore, OFDM can fulfill the requirements of 5G wireless networks in a limited way. In order to overcome some of these drawbacks of OFDM, new modulation techniques for 5G communication systems are considered. Among them, Filter bank multicarrier (FBMC), and Universal filtered multicarrier (UFMC) are expected be in race to be considered for the selection. In this paper, we perform the performance analysis of OFDM, UFMC, and FBMC in terms of its spectral efficiency (SE), power spectral density (PSD), peak to average power ratio (PAPR), and bit error rate (BER) using the MATLAB software tools. We analyze the results by varying the parameters of the modulation techniques which affects the performance of OFDM, UFMC, and FBMC. The plot shows that, FBMC has better SE for large burst durations but for small burst duration the SE of UFMC is better. In terms of PSD and BER FBMC is better. In terms of PAPR UFMC is better. The result of this research will play a significant role in selecting efficient modulation scheme for the upcoming 5G cellular networks