Research on Image Transmission in Wireless Systems Based on MIMO
Students Name: Kolodka Yurii Volodymyrovych
Qualification Level: magister
Speciality: System Administration of Telecommunications Networks
Institute: Institute of Telecommunications, Radioelectronics and Electronic Engineering
Mode of Study: full
Academic Year: 2024-2025 н.р.
Language of Defence: ukrainian
Abstract: Wireless data transmission systems have become essential in today’s digital landscape, with transmission speed being the primary measure of their effectiveness. However, merely achieving high data rates isn’t sufficient; maintaining the quality of transmitted information is equally crucial [1,2]. Signal distortion during audio, video, or image transmission can notably impact information perception. Currently, various wireless communication technologies are widely implemented. For example, mobile networks and local area networks utilizing the 802.11 standard have become popular, with MIMO 802.11n technology standing out for its superior bandwidth [3,4]. While Wi-Fi is primarily used for short-range networking, WiMAX technology enables the establishment of wireless networks across extended distances. One of the biggest challenges in wireless networks is the complex behavior of signal propagation, which is heavily influenced by specific environmental factors. Industrial interference, multipath propagation, and the movement of a mobile station relative to a base station all complicate network functionality and affect channel capacity [5]. Transmitting images over wireless channels is a pressing issue addressed in multiple studies. However, many works assume an idealized channel with additive Gaussian noise, which does not fully capture real-world conditions, particularly in dense urban areas. Moreover, these studies often overlook spatial filtering algorithms that can mitigate multipath reflections with varying delays, amplitude, phase distortions, and arrival angles. Adaptive spatial filtering can help minimize signal distortion from multipath effects by forming a desired directional pattern. This approach enables focusing on the primary path of the signal, reducing interference and distortion at the receiver. The research object is image transmission, and the subject is wireless communication systems. The purpose of this thesis is to enhance bandwidth and reduce the bit error probability in image transmission over radio communication channels. The first chapter explores WiMAX technology, focusing on its potential to improve spectral efficiency in medium-range communication systems. The analysis examines systems using spatial-temporal signal processing, evaluating MIMO technology’s capacity to expand wireless channel capacity. Fundamental concepts in adaptive signal processing for wireless systems are introduced. The second section addresses factors influencing signal behavior in wireless channels, including propagation losses, shadowing, reflection, diffraction, scattering, and attenuation. A 3D channel model that accounts for signal reflection angles is presented, developed based on the 3GPP/WiMAX framework. This model illustrates reflections from buildings, objects, and the ground, as well as the direct signal path. Various spatial processing techniques applied in multiple-antenna coding are analyzed. In the third chapter, the main aspects of the image transmission algorithm are examined, with the development of a modeling algorithm and an adaptation unit tailored for antenna array-based communication systems. The fourth section presents models of SISO and MIMO systems without an adaptive block, enabling comparison of noise resilience under different OFDM subcarrier modulation schemes. The analysis shows how channel throughput changes with various antenna configurations in systems utilizing spatial-temporal processing. Wireless systems are modeled with an adaptive processing unit that uses spatial filtering to minimize interference from re-reflected signals. The bit error probability in SISO and MIMO systems was calculated for different adaptive processing unit configurations, with throughput results also provided. In the fifth chapter, an economic assessment is conducted for energy-efficient architectures in modern wireless communication systems, demonstrating the project’s feasibility based on financial calculations. Keywords: MIMO; WiMAX; wireless channel; modulation.