• Title/Summary/Keyword: Polar transmitter

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Novel Polar Transmitter with 2-Bit Sigma-Delta Modulation (2비트 시그마-델타 변조를 이용한 새로운 폴라 트랜스미터)

  • Lim, Ji-Youn;Cheon, Sang-Hoon;Kim, Kyeong-Hak;Hong, Song-Cheol;Kim, Dong-Wook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.8
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    • pp.970-976
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    • 2007
  • This paper presents a novel polar transmitter architecture with a 2-bit sigma-delta modulator. In the proposed architecture, the 2-bit sigma-delta modulator is introduced to suppress quantization noise of conventional sigma-delta modulator. The power amplifier configuration is also modified in a binary form to accommodate the 2-bit digitized envelope signal. The Ptolemy simulation results of the proposed structure show that the spectral property is greatly improved in full transmit band of EDGE system. The fine quantization scheme of the 2-bit modulator lowers the noise level by 10dB without increasing the over-sampling ratio, which may be obtained if the over-sampling ratio increases twofold. Dynamic range is also enhanced up to 5dB owing to the new form of the power amplifier in the transmitter.

Binary Power Amplifier with 2-Bit Sigma-Delta Modulation Method for EER Transmitter

  • Lim, Ji-Youn;Cheon, Sang-Hoon;Kim, Kyeong-Hak;Hong, Song-Cheol;Kim, Dong-Wook
    • ETRI Journal
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    • v.30 no.3
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    • pp.377-382
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    • 2008
  • A novel power amplifier for a polar transmitter is proposed to achieve better spectral performance for a wideband envelope signal. In the proposed scheme, 2-bit sigma-delta (${\Sigma}{\Delta}$) modulation of the envelope signal is introduced, and the power amplifier configuration is modified in a binary form to accommodate the 2-bit digitized envelope signals. The 2-bit ${\Sigma}{\Delta}$ modulator lowers the noise of the envelope signal by fine quantization and thus enhances the spectral property of the RF signal. The Ptolemy simulation results of the proposed structure show that the spectral noise is reduced by 10 dB in a full transmit band of the EDGE system. The dynamic range is also enhanced. Since the performance is improved without increasing the over-sampling ratio, this technique is best suited for wireless communication with high data rates.

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Design of a Chaotic Spread Spectrum Communication System using Polar Quarternary Method (복극4레벨 데이타 방식을 이용한 혼돈 대역확산 통신계통 설계)

  • 유충현;정종은;박광현;박진수
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.35C no.10
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    • pp.12-21
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    • 1998
  • A chaotic spread spectrum communication system using a polar quarternary method is designed and implemented. Four different chaotic signals in the relation of multiplication each other are generated through the use of a coupled synchronization method in the transmitter which is composed of four Chua's circuits. Information is retrieved at the receiver which is connected to the transmitter through the use of a drive synchronization method. Since spread spectrum of information signal is spread by chaotic signal, the configuration of the system is simpler than that of any other conventional system.

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Analysis of Radio Environments Allocated to HF Ocean Surface Radar in Korea (고주파(HF) 해양레이더 운용에 분배된 국내 주파수 전파 환경 분석)

  • Song, Kyu-Min
    • Ocean and Polar Research
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    • v.38 no.4
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    • pp.325-330
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    • 2016
  • Partial high frequency bands were allocated to the operation of ocean surface radars that monitor the sea surface currents and waves in WRC-12. On that basis, government-related organizations revised the table of domestic frequency allocation. In order to study radio environments in the allocated bands for ocean radar, tests of the radio signal spectrum were carried at 7-sites using the receiver of the ocean surface radar system operated with a shutdown of the transmitter for 10-60 min. The results showed that no serious radio noises occur at 25 and 43 MHz bands, indicating a good radio environment for the ocean surface radar operation. However, at 13 MHz band, it was difficult to generate stable and confidential data from the ocean surface radar because serious radio noises occurred continuously.

Class-E CMOS PAs for GSM Applications

  • Lee, Hong-Tak;Lee, Yu-Mi;Park, Chang-Kun;Hong, Song-Cheol
    • Journal of electromagnetic engineering and science
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    • v.9 no.1
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    • pp.32-37
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    • 2009
  • Various Class-E CMOS power amplifiers for GSM applications are presented. A stage-convertible transformer for a dual mode power amplifier is proposed to increase efficiency in the low-output power region. An integrated passive device(IPD) process is used to reduce combiner losses. A split secondary 1:2 transformer with IPD process is designed to obtain efficient and symmetric power combining. A quasi-four-pair structure of CMOS PA is also proposed to overcome the complexities of power combining.

Application of real-time satellite based DCS (Data Collection System) in the ocean and fisheries (해양 ${\cdot}$ 수산에 대한 DCS기반 실시간 위성중계수집 시스템의 활용)

  • Yoon, Hong-Joo;Suh, Young-Sang
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.344-351
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    • 2005
  • It was discussed to satellite based DCS (NOAA, Orbcomm, ADEOS-II, CBERS in polar satellite and GMS, GOES, METEOSAT, INSAT, FY-2 in geostationary satellite) with PTT (Platform Transmitter Terminal) and DCP (Data collection Platform) in order to application of real-time DCS (Data Collection System) in the ocean and fisheries. For covering ocean data link area in the eastern hemisphere, it was proposed to take DCS on the Korean geostationary satellite in the marine environments.

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Development of Deep Learning Model for Fingerprint Identification at Digital Mobile Radio (무선 단말기 Fingerprint 식별을 위한 딥러닝 구조 개발)

  • Jung, Young-Giu;Shin, Hak-Chul;Nah, Sun-Phil
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.1
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    • pp.7-13
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    • 2022
  • Radio frequency fingerprinting refers to a methodology that extracts hardware-specific characteristics of a transmitter that are unintentionally embedded in a transmitted waveform. In this paper, we put forward a fingerprinting feature and deep learning structure that can identify the same type of Digital Mobile Radio(DMR) by inputting the in-phase(I) and quadrature(Q). We proposes using the magnitude in polar coordinates of I/Q as RF fingerprinting feature and a modified ResNet-1D structure that can identify them. Experimental results show that our proposed modified ResNet-1D structure can achieve recognition accuracy of 99.5% on 20 DMR.

3-Level Envelope Delta-Sigma Modulation RF Signal Generator for High-Efficiency Transmitters

  • Seo, Yongho;Cho, Youngkyun;Choi, Seong Gon;Kim, Changwan
    • ETRI Journal
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    • v.36 no.6
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    • pp.924-930
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    • 2014
  • This paper presents a $0.13{\mu}m$ CMOS 3-level envelope delta-sigma modulation (EDSM) RF signal generator, which synthesizes a 2.6 GHz-centered fully symmetrical 3-level EDSM signal for high-efficiency power amplifier architectures. It consists of an I-Q phase modulator, a Class B wideband buffer, an up-conversion mixer, a D2S, and a Class AB wideband drive amplifier. To preserve fast phase transition in the 3-state envelope level, the wideband buffer has an RLC load and the driver amplifier uses a second-order BPF as its load to provide enough bandwidth. To achieve an accurate 3-state envelope level in the up-mixer output, the LO bias level is optimized. The I-Q phase modulator adopts a modified quadrature passive mixer topology and mitigates the I-Q crosstalk problem using a 50% duty cycle in LO clocks. The fabricated chip provides an average output power of -1.5 dBm and an error vector magnitude (EVM) of 3.89% for 3GPP LTE 64 QAM input signals with a channel bandwidth of 10/20 MHz, as well as consuming 60 mW for both channels from a 1.2 V/2.5 V supply voltage.