Institute of Technology

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    PERFORMANCE COMPARISON OF CHANNEL MODELS FOR UFMC SYSTEM
    (Hawassa University, 2019-08-29) TILAHUN BELAYNEH MAMO
    This paper presents the bit error rate (BER) vs. signal-to-noise (SNR) ratio performance of channel models under UFMC system with 32- FSK, PAM, DPSK, 4-QAM, 16-QAM, 32-QAM, 64-QAM and 128-QAM modulation. In future it is believed to be more challenging and complicated with the evolution of different types of fading model. These types of fading models determined in urban and rural areas. Rayleigh fading model is considered to be most common fading model, found in urban environment for non-line of sight. Rician fading consists of line of sight communication and found to be more applicable for satellite communication. Nakagami fading model is mostly suited for urban multipath propagation and it is sought to be most practical model, specially used in mobile communication. In order to achieve error free signal at the receiver the choice of modulation scheme should be done wisely. The combination of best efficient modulation scheme along with the block coding helps in getting the signal error free at the receiver. The condition of signal is decided by SNR v/s BER (bit error rate) simulation. Our main objective is to get error free result at the receiver, so for this different data transmission techniques are used to transmit the data from transmitter to receiver in various fading channels under different modulation schemes. Effect of shape factor on Nakagami fading is also covered in this thesis to get efficient results. The BER performance was to compared with Additive White Gaussian Noise (AWGN), Rayleigh-faded, Nakagami-m faded and Rician-faded channels. It has been further concluded that the BER vs. SNR performance graph in AWGN channel environment is better than that in Rayleigh, Nakagami-m and Rician-faded channel. It is also observed that by varying the standard-deviation of the channel, the BER vs. SNR performance graph is not going to be affected if the channel is considered Rayleigh-faded. In this paper we address a new aspect of UFMC system performance by investigating its capability to overcome the channel fading channels’ effects and to provide good and reliable performance levels overcome these channel effects.
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    OPERATIONAL ANALYSIS OF UNSIGNALIZED INTERSECTION AND ROUNDABOUT UNDER MIXED TRAFFIC FLOW CONDITION OF SELECTED INTERSECTIONS IN ADAMA CITY
    (Hawassa University, 2020-10-06) DARARA BERHANU KURU
    Urban traffic congestion is currently severe in most cities in the world due to economic and social development. Prevalently, Ethiopia is one of the countries that are in rapid economic development. This influences the travel pattern of the community from their origin to any destination. Adama is one of busy transportation center in Ethiopia. The city is situated along the road that connects Addis Ababa with Dire Dawa. A large number of trucks use this same route to travel to and from the seaports of Djibouti. A little attention has been paid to junctions and their capacities. There are a few studies conducted to assess the capacity of junctions in Adama. The main objective of this study was to evaluate operational performance on both unsignalized and roundabout junctions which are necessary for transport professional’s and governors to put tangible information for future traffic growth of Adama city. This thesis addresses the most important element of operational performance of unsignalized intersections and roundabouts traffic intersections in Adama City on capacity analysis. The methodology employed for this study was the quantitative descriptive research design which used quantitative data and analyzed using SIDRA 8.1 intersection software model. The movements of the vehicles were observed at three roundabouts and seven unsignalized intersections for a duration of two hours. The necessary geometric data for the analysis (average entry width, circulatory road width, number of entry and circulatory lanes, and island diameter), traffic movement data with vehicle characteristics and pedestrian volume were collected. The capacity analysis was done based on the gap acceptance method that is adopted by SIDRA 8.1 software program. Based on analysis results, Derartu Tulu roundabouts and six of selected unsignalized intersections i.e Mebrathayil,Sartera,Wonji,Tikur Abay and Alem Hotel junctions are currently serving in poor condition of level of service of F by having v/c ratio >1. Genda Gara and Medanihalem roundabouts are serving at their best operating condition having level of service A.The rest two unsignalized intersection Geda and Diamond Cafe have level of service of D and C respectively. The overall level of service of the unsignalized intersections and roundabouts are serving at poor level of service. Thus, after carrying out additional detail investigation and taking into consideration future traffic growth appropriate improvement should be made by concerned bodies