Генерація та аналіз радіочастотних сигналів системи Wi-Sun

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dc.contributor.advisorПрокопенко, Юрій Васильович
dc.contributor.authorКостик, Антон Сергійович
dc.date.accessioned2023-08-29T09:40:56Z
dc.date.available2023-08-29T09:40:56Z
dc.date.issued2023
dc.description.abstractОб’єктом розгляду роботи є система Wi-Sun. Предмет роботи – аналіз та аналіз радіочастотних характеристик, отриманих за допомогою MTP 300. Метою роботи є огляд побудови генератора Wi-Sun сигналів для тестування приймачів та вимірювання радіочастотних характеристик передавачів. Перший розділ включає опис способів маніпуляції в Wi-Sun, також модулятор та демодулятор кожного з них. Другий розділ містить інформацію про формат даних для передачі інформації, а саме формат даних для FSK. У третьому розділі ідеться про OFDM. Розглядаються основні принципи генерації сигналу та ортогональність. Четвертий розділ складається з опису квадратурного сигналу, квадратурного передавача та приймача. П’ятий розділ полягає у вимірюванні радіочастотних характеристик за допомогою методу частотної модуляції, та мови сі.uk
dc.description.abstractotherThe object of the work is the Wi-Sun system. The subject of work is the analysis and analysis of radio frequency characteristics obtained using the MTP 300. The purpose of the work is to review the construction of a Wi-Sun signal generator for testing receivers and measuring the radio frequency characteristics of transmitters. The first section includes a description of the ways of manipulating Wi-Sun, as well as the modulator and demodulator of each of them. The second section contains information about the data format for transmitting information, namely the data format for FSK. The third section deals with OFDM. The basic principles of signal generation and orthogonality are discussed. The fourth section consists of a description of the quadrature signal, quadrature transmitter, and receiver. The fifth chapter is about measuring radio frequency characteristics using the frequency modulation method and the C language. The purpose of the first section is to familiarize you with the manipulation methods and how they work. There are quite a few of them, but only a few have been considered, namely frequency shift keying (FSK), 2FSK, 4FSK, phase shift keying (PSK), binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), and octal phase shift keying (OQPSK). In frequency manipulation, information is encoded on the signal carrier by periodically shifting the carrier frequency between several discrete frequencies. In 2-FSK, bits or binary digits are used as input signals and symbols are generated as output. In 4-FSK, bits are used as input signals and symbols are generated at the output. The difference between 2-FSK and 4-FSK is that in 4-FSK, each symbol carries information about two bits. This allows you to double the data rate compared to 2-FSK modulation. PSK is a manipulation method in which the phase of the carrier signal is changed to represent different symbols or bits of information. PSK is of two types: binary phase-shift keying (BPSK) and quadrature phase-shift keying (QPSK). BPSK uses two phases separated by 180. BPSK can only modulate data at a rate of 1 bit/symbol, making it incompatible with high-speed data applications. QPSK uses four points in a constellation diagram, spaced evenly around a circle. QPSK can double the data rate compared to BPSK while maintaining the same signal bandwidth. QPSK has an advantage over BPSK because it transmits twice the data rate in a given frequency band. Quadrature phase-shift keying (OQPSK) is a variant of phase-shift keying modulation that uses four different phase values for transmission. OQPSK has smaller amplitude fluctuations because the phase changes are limited to 90. The purpose of Section 2 is to describe the frequency-shift keying (FSK) data format. In Wi-Fi systems, information is transmitted in frames (packets) called Physical Protocol Data Unit (PPDU). The PPDU format depends on the type of manipulation. The FSK PPDU (Physical Protocol Data Unit) must support a format that contains such fields as SHR, PHR, PHY payload. The SHR field must follow the format (Preamble, SFD).The Preamble field must contain the length phyFskPreambleLength, a multiple of the 8-bit sequence "01010101" for 2-FSK. And for 4-FSK, the Preamble field must contain the value of phyFskPreambleLength, a multiple of the 16-bit sequence "0111 0111 0111 0111 0111". For 2-FSK modulation, the SFD (Start of Frame Delimiter) in Wi-SUN must consist of a 2-octet sequence, and for 4-FSK modulation, the SFD must be a 4-octet sequence. Thus, the SFD format for 2-FSK and 4-FSK modulation in Wi-Fi is determined by the specified octet sequences. The purpose of Chapter 3 is to describe orthogonal frequency division multiplexing (OFDM). It is based on dividing the available frequency spectrum into several orthogonal subcarriers, each of which carries a separate data stream. OFDM is based on the well-known method of frequency division multiplexing (FDM). In FDM, different streams of information are mapped to separate parallel frequency channels. Each FDM channel is separated from the others by a frequency guard band, which reduces interference between neighboring channels. A simple OFDM system uses N sinusoidal input signals. Each subcarrier transmits one bit of information, which is reflected by the presence or absence of this subcarrier in the output spectrum. The frequency of each subcarrier is chosen to create an orthogonal set of signals. These frequencies are also known to the receiver for signal recovery. The original data is updated with a period T, which defines the period of the symbol. To maintain orthogonality, T must be the inverse of the subcarrier spacing. An OFDM signal can be described as a set of subcarriers spaced close together in the frequency domain. Each transmitted subcarrier in the frequency domain generates a sinusoidal function spectrum with side lobes that create overlapping spectra between subcarriers. The purpose of Chapter 4 is to describe quadrature signals and the principle of operation of a quadrature transceiver. A quadrature signal is a two-dimensional signal that can be represented by a complex number composed of in-phase (I) and quadrature (Q) components. They correspond to the real and imaginary parts, or in-phase and quadrature phase. "In-phase" and "quadrature" refer to two sinusoidal signals with the same frequency that are 90 out of phase. Typically, an I-signal is a cosine waveform, and a Q-signal is a sine waveform. I/Q signals are always amplitude modulated, not frequency or phase modulated. In an I/Q modulator, the signals that modulate the I/Q sine waves are not shifted so that they are always positive. A quadrature receiver uses an oscillator and two mixers to reduce the radio wave to low frequencies. Two signals with a 90-degree phase shift are fed to the mixers. The Fourier transform is applied to reduce the frequency of the signal to low values. Both processed signals are then passed through low-pass filters with a cutoff frequency of less than 2_0. The resulting quadrature and in-phase components are then sampled in an analog-to-digital converter, which converts them into discrete I and Q values. Using these two parameters, we can visualize the resulting point on the phase constellation and obtain its digital value. In the case of the transmitter, the modulated I and Q values are input to the mixers, which also receive signals from the carrier frequency generator with a 90-degree phase shift. After that, these two components are combined in an adder and fed to a local oscillator, where the frequency is increased to the carrier frequency. The purpose of Part 5 is to generate and analyze radio frequency characteristics. Frame generation was implemented in the form of a block diagram. Each block was implemented in the C language. These programs allow you to generate a Wi-Fi frame in the form of I/Q samples with a given sampling rate. This data array was loaded into the MTP 300 measuring platform, which generated an analog radio frequency signal of a given power, which was transmitted to the Wi-Fi receiver. The frequency modulation method is used to measure the modulation response. In the frequency modulation (FM) method, the instantaneous frequency of the carrier varies depending on the amplitude of the modulating signal.uk
dc.format.extent63 с.uk
dc.identifier.citationКостик, А. С. Генерація та аналіз радіочастотних сигналів системи Wi-Sun : дипломна робота … бакалавра : 153 Мікро- та наносистемна техніка / Костик Антон Сергійович. – Київ, 2023. – 63 с.uk
dc.identifier.urihttps://ela.kpi.ua/handle/123456789/59602
dc.language.isoukuk
dc.publisherКПІ ім. Ігоря Сікорськогоuk
dc.publisher.placeКиївuk
dc.subjectспособи маніпуляціїuk
dc.subjectчастотна маніпуляціяuk
dc.subjectвимірювання радіочастотних характеристикuk
dc.titleГенерація та аналіз радіочастотних сигналів системи Wi-Sunuk
dc.typeBachelor Thesisuk

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