USRP/LTE를 이용한 CDMA기반 양방향 군탐색구조 시스템 시작품 제작

정인철,최상혁,이상욱,안우근 한국위성정보통신학회 2016 한국위성정보통신학회논문지 Vol.11 No.4

본 논문은 USRP와 LTE를 이용하여 CDMA 양방향 군탐색구조 시스템의 시작품 제작에 대한 내용을 기술하고 있다. 상용 LTE망에 의한 양방향 탐색구조 시스템과 USRP를 이용하여 COSPAS SARSAT의 새로운 규격인 Spread Spectrum 방식의 신호체계를 구현 하여 RF신호를 생성하고 송출하여 수신한 결과에 대한 내용을 포함하고 있다. This paper describes the prototyping of CDMA bi - directional group search system using USRP and LTE. This paper describes the results of RF signal generation and transmission by implementing a spread spectrum signaling system, which is a new standard of COSPAS SARSAT, using a bi-directional search structure system using commercial LTE network and USRP.

USRP와 LabVIEW를 이용한 GPS L1C/A 신호 저장 시스템

황용택,황지우,김민수,유호영 대한전자공학회 2023 전자공학회논문지 Vol.60 No.11

Global Positioning System(GPS)이 제공하는 위치, 속도, 시간 정보를 이용하는 서비스가 다양해지면서 이를 이용하기 위해 이전보다 많은 곳에 GPS 수신기가 탑재되고 있다. 이에 따라 GPS 수신기가 신호를 수신받는 환경이 다양해지면서 신호를 안정적으로 수신하기 위해 수신기의 성능을 향상시키는 연구가 진행되고 있다. 이러한 연구에서는 위성 신호를 저장할 수 있는 시스템을 구축하는 것이 중요하다. 따라서, 본 논문에서는 Universal Software Radio Peripheral(USRP)과 LabVIEW를 활용하여 GPS L1C/A 신호를 저장하는 시스템을 구축하였다. 안테나, 라인 증폭기, 그리고 USRP와 같은 하드웨어 구성 요소들을 사용했으며, USRP를 제어하기 위하여 LabVIEW를 사용하였다. 구성한 신호 저장 시스템을 검증하기 위해 저장한 GPS L1C/A 신호를 Software Defined Radio(SDR)를 이용하여 처리하고, 상용 수신기로부터 얻은 결과와 비교하였다. 이를 통해 저장된 신호들이 Pseudo-Random Noise(PRN) 번호와 신호의 전력 수준 측면에서 실제 신호들과 일치함을 확인하였다. As services that use location, speed, and time information provided by the Global Positioning System(GPS) become more diverse, GPS receivers are being installed in more places than before to use that information. As a result, as the environment in which GPS receivers receive signals becomes more diverse, research is being conducted to improve the performance of receivers to receive signals stably. In these studies, it is important to establish a system capable of storing satellite signals. Therefore, in this paper, a system for storing GPS L1C/A signals was established using Universal Software Radio Peripheral(USRP) and LabVIEW. Hardware components such as antennas, line amplifiers, and USRP were used, and LabVIEW was used to control USRP. To verify the configured signal storage system, the stored GPS L1C/A signal was processed using Software Defined Radio(SDR) and compared with the results obtained from commercial receivers. Through this, it was confirmed that the stored signals were consistent with the actual signals in terms of the pseudo-Random Noise (PRN) number and the power level of the signal.

USRP를 이용한 64-QAM OFDM 소프트웨어 정의 라디오 구현

김민수(Min-Su Kim),김영식(Young-Sik Kim) 한국전자파학회 2021 한국전자파학회논문지 Vol.32 No.3

본 논문에서는 OFDM(orthogonal frequency division multiplexing) 신호의 비트 오류율을 낮추기 위해 USRP(universal software radio peripheral)를 최적화하여 소프트웨어 정의 라디오를 구현하였다. 시스템의 하드웨어 플랫폼으로 USRP B200을 이용하며, 802.11a WiFi 표준 OFDM 신호를 송 · 수신한다. 무선 통신을 위해 64-QAM 변조 방식을 사용하였고, 간섭을 피하기 위해 반송파 주파수를 2.61 ㎓로 설정하였다. OFDM 신호의 경우, 높은 PAPR(peak to average power ratio)을 가지고 있어 송 · 수신단의 선형성 최적화가 필요하다. USRP의 선형성 최적화를 위해 14 ㏈의 Back-off를 설정하였으며, 기저대역 20 ㎒ 신호를 40 ㎒로 업샘플링하고 디지털 필터를 추가하였다. 구현한 통신 시스템의 성능을 분석하기 위하여 신호 대 잡음비에 따른 비트 오류율을 측정하였고, 오류 정정 없이 최대 1.75×10<SUP>−6</SUP>의 비트 오류율을 획득하였다. 그리고 무선 통신 채널에서 발생하는 오류를 정정하기 위해 오류 정정 코드를 추가하여 이미지 데이터를 송 · 수신한 결과, 비트 오류 없이 데이터를 송 · 수신하였다. In this study, a software-defined radio based on orthogonal frequency division multiplexing (OFDM) is implemented to optimize universal software radio peripheral (USRP) for the optimal bit error rate. Two USRP B200s are used as the hardware platform, and an OFDM signal of 802.11a WiFi standard is used. The wireless system works with 64-QAM modulation and operates at the carrier frequency of 2.61 ㎓ to avoid interference. An OFDM signal generally has a large peak to average power ratio (PAPR) such that the transceiver is optimized to obtain the linearity requirement. To optimize the linearity of the USRP, a 14 ㏈ back-off is set, and the base band signal of 20 ㎒ is up-sampled to 40 ㎒. In addition, a digital filter is added to eliminate the unwanted signals. To analyze the performance of the implemented system, the bit error rate to signal-to-noise ratio is measured, and a maximum bit error rate of 1.75×10<SUP>−6</SUP> is obtained without error correction. Furthermore, the standard channel codes are implemented to correct the bit errors occurring in a wireless channel. The image data are successfully transmitted and received without bit errors by using the channel codes.

2개의 안테나 소자를 갖는 Time-Modulated Array와 하나의 USRP를 이용한 실시간 방향탐지 시스템의 구현

이상준(Sangjoon Lee),윤현구(Hyungoo Yoon),추호성(Hosung Choo),장병준(Byung-Jun Jang) 한국전자파학회 2017 한국전자파학회논문지 Vol.28 No.4

본 연구에서는 TMA(Time-Modulated Array)와 USRP(Universal Software Radio Peripheral)를 이용하여 2.4 GHz 대역에서 동작하는 실시간 방향탐지 시스템을 구현하였다. 구현된 시스템은 2개의 상용 모노폴 안테나, 자체 제작한 스위치 보드, 그리고 하나의 USRP로만 구성되며, LabVIEW로 연동하여 실시간으로 특정 신호원의 입사 각도를 탐지할 수 있었다. 구현결과, 30°의 범위 내에서 최대 4°의 오차 이내로 방향탐지가 가능함을 확인하였다. 제안한 시스템은 기존의 다중수신기를 갖는 방향탐지 시스템에 비해 하드웨어 구성이 간단할 뿐만 아니라, 주엽과 첫 번째 부엽 신호의 크기만을 이용하는 간단한 계산으로 방향탐지가 가능하다는 장점이 있다. In this paper, we implemented a real-time 2.4 GHz direction finding system using a time-modulated array(TMA) and an Universal Software Radio Peripheral(USRP). Our system consists of two commercial monopole antennas, self-designed switch board, and an USRP, and it is controlled using LabVIEW program in real-time. From measured results, it is verified that our system can exactly detect the incident angle within 4 degree in the range of 30 degree. Our direction finding system has advantages of a simple hardware architecture than conventional one with multiple receivers, and a simple algorithm only by using a main lobe and a first side-lobe of switching frequency.

WPAN 간섭원에 의한 MIMO-OFDM WLAN의 성능 열화 분석을 위한 실시간 주파수 간섭 분석 시스템

윤현구(Hyungoo Yoon),박진수(Jin-Soo Park),장병준(Byung-Jun Jang) 한국전자파학회 2016 한국전자파학회논문지 Vol.27 No.1

본 논문에서는 WPAN(Wireless Personal Area Network) 주파수 간섭원에 의한 MIMO(Multi Input Multi Output)-OFDM (Orthogonal Frequency Division Multiplexing) WLAN(Wireless Local Area Network)의 성능 열화를 분석하기 위해 LabVIEW 와 USRP (Universal Software Radio Peripheral)를 이용한 실시간 주파수 간섭 분석 시스템을 제안하였다. 제안한 시스템은 간섭원과 피간섭원을 각각 소프트웨어로 구현하고, USRP와 연결하여 실제 시스템과 유사한 2.4 GHz 대역의 송신신호를 발생시킨 후, 피간섭원의 수신과정에 잡음신호 및 간섭신호와 결합하여, 주파수 공동사용에 따른 MIMO 시스템의 BER (Bit Error Rate)을 분석하는 방식이다. 분석 결과, 이론값과 거의 일치하는 결과를 보여 제안한 시스템의 타당성을 입증하였다. In this paper, we have proposed the frequency interference analysis system using both LabVIEW and Universal Software Radio Peripheral(USRP) for performance degradation analysis of Multi Input Multi Output-Orthogonal Frequency Division Multiplexing(MIMO-OFDM) Wireless Local Area Network(WLAN) due to Wireless Local Area Network(WPAN) interferer. The proposed system consists of three part, i.e., victim, channel, and interferer. Both victim and interferer are implemented by LaBVIEW and a USRP board. Then interfering signal and additive white Gaussian noise are combined with the wanted signals of a victim. Measured Bit Error Rate(BER) at the victim receiver is compared with theoretical BER according to various signal to interference plus noise power ratio (SINR) values. Measured and theoretical BER curves show good agreement.

Implementation of Spectrum Sensing with Video Transmission for Cognitive Radio using USRP with GNU Radio

Huynh Thanh Thien,Hiep Vu-Van,Insoo Koo 한국인터넷방송통신학회 2018 International Journal of Internet, Broadcasting an Vol.10 No.1

In cognitive radio (CR), secondary users (SUs) are able to sense the absence of primary users (PUs) in the spectrum. Then, SUs use this information to opportunistically access the licensed spectrum in the PUs’ absence. In this paper, we present an implementation of real-time video transmission with spectrum-sensing between two points using GNU Radio and a National Instruments 2900 Universal Software Radio Peripheral (USRP). In our project, spectrum-sensing is implemented at both transmitter and receiver. The transmitter senses the channel, and if the channel is free, a video signal (which could be a real-time signal from a video file) will be modulated and processed by GNU Radio and transmitted using a USRP. A USRP receiver also senses the channel, but in contrast, if the channel is busy, the signal is demodulated to reproduce the transmitted video signal. This project brings in several challenges, like spectrum-sensing in the devices’ environment, and packets getting lost or corrupted over the air.

Implementation of Spectrum Sensing with Video Transmission for Cognitive Radio using USRP with GNU Radio

Thien, Huynh Thanh,Vu-Van, Hiep,Koo, Insoo The Institute of Internet 2018 International Journal of Internet, Broadcasting an Vol.10 No.1

In cognitive radio (CR), secondary users (SUs) are able to sense the absence of primary users (PUs) in the spectrum. Then, SUs use this information to opportunistically access the licensed spectrum in the PUs' absence. In this paper, we present an implementation of real-time video transmission with spectrum-sensing between two points using GNU Radio and a National Instruments 2900 Universal Software Radio Peripheral (USRP). In our project, spectrum-sensing is implemented at both transmitter and receiver. The transmitter senses the channel, and if the channel is free, a video signal (which could be a real-time signal from a video file) will be modulated and processed by GNU Radio and transmitted using a USRP. A USRP receiver also senses the channel, but in contrast, if the channel is busy, the signal is demodulated to reproduce the transmitted video signal. This project brings in several challenges, like spectrum-sensing in the devices' environment, and packets getting lost or corrupted over the air.

USRP와 GNU Radio를 이용한 IEEE 802.15.4 물리 계층 소프트웨어 라디오 시스템 구현

박대현(Dae-Hyeon Park),김영식(Young-Sik Kim) 한국전자파학회 2010 한국전자파학회논문지 Vol.21 No.11

본 논문은 소프트웨어 라디오 범용 하드웨어인 USRP(Universal Software Radio Peripheral) 보드와 오픈 소스 소프트웨어 라디오 개발 툴킷인 GNU Radio 패키지를 사용하여 저속, 저전력 무선 표준인 IEEE 802.15.4 표준의 물리 계층을 구현하였다. 본 논문에서 구현한 소프트웨어 라디오 시스템은 IEEE 802.15.4 물리 계층 중 868/915 ㎒ 대역의 BPSK와 OQPSK 변조 방식의 송수신 물리 계층과 2.45 ㎓ 대역의 OQPSK 변조 방식의 물리 계층을 지원하도록 구현하였다. 또한, 구현된 소프트웨어 라디오의 시스템의 검증을 위해, 각 주파수 대역과 변조방식을 표준에 정의된 대역 특성, 패킷 구조에 맞추어 설정하고, 송수신 테스트를 수행하였으며, 특히 2.4 ㎓ 대역은 CC2430 모듈과 Smart RF EV 보드를 이용하여 정상 동작을 확인하였다. 그리고 시스템의 성능은 송신신호의 PSD 마스크 조건과 수신 상태의 아이 패턴, PER(패킷 에러율) 테스트 결과로 구현한 시스템의 성능을 검증하였다. 그 결과, 구현한 시스템이 IEEE 802.15.4 물리 계층 표준에 부합함을 확인하였다. In this paper, a software radio system, supporting the physical layer of IEEE 802.15.4 standard, has been developed using USRP(Universal Software Radio Peripheral) board and GNU Radio package of an open source development kit for software radio. The software radio system supports the standards of BPSK and OQPSK modulations for 868/915 ㎒ band and OQPSK modulation for 2.45 ㎓ band. To verify the operation of the developed system, it has been tested under the standard signals according to the frequency band and packet structures for the transmitting and receiving operation. At 2.4 ㎓, the Smart RF EV board and CC2430 modules are used to check the proper operation of the software radio system. The system performance test shows that the emission power spectrum, the eye-pattern, and PER(Packet Error Rate) meet the standard. It has been confirmed that the developed system supports the PHY layer of IEEE 802.15.4.

A Performance Analysis of Multi-GNSS Receiver with Various Intermediate Frequency Plans Using Single RF Front-end

Park, Kwi Woo,Chae, Jeong Geun,Song, Se Phil,Son, Seok Bo,Choi, Seungho,Park, Chansik The Institute of Positioning 2017 Journal of Positioning, Navigation, and Timing Vol.6 No.1

In this study, to design a multi-GNSS receiver using single RF front-end, the receiving performances for various frequency plans were evaluated. For the fair evaluation and comparison of different frequency plans, the same signal needs to be received at the same time. For this purpose, two synchronized RF front-ends were configured using USRP X310, and PC-based software was implemented so that the quality of the digital IF signal received at each front-end could be evaluated. The software consisted of USRP control, signal reception, signal acquisition, signal tracking, and C/N0 estimation function. Using the implemented software and USRP-based hardware, the signal receiving performances for various frequency plans, such as the signal attenuation status, overlapping of different systems, and the use of imaginary or real signal, were evaluated based on the C/N0 value. The results of the receiving performance measurement for the various frequency plans suggested in this study would be useful reference data for the design of a multi-GNSS receiver in the future.

A Performance Analysis of Multi-GNSS Receiver with Various Intermediate Frequency Plans Using Single RF Front-end

박귀우,채정근,송세필,손석보,최승호,박찬식 사단법인 항법시스템학회 2017 Journal of Positioning, Navigation, and Timing Vol.6 No.1

In this study, to design a multi-GNSS receiver using single RF front-end, the receiving performances for various frequency plans were evaluated. For the fair evaluation and comparison of different frequency plans, the same signal needs to be received at the same time. For this purpose, two synchronized RF front-ends were configured using USRP X310, and PCbased software was implemented so that the quality of the digital IF signal received at each front-end could be evaluated. The software consisted of USRP control, signal reception, signal acquisition, signal tracking, and C/N0 estimation function. Using the implemented software and USRP-based hardware, the signal receiving performances for various frequency plans, such as the signal attenuation status, overlapping of different systems, and the use of imaginary or real signal, were evaluated based on the C/N0 value. The results of the receiving performance measurement for the various frequency plans suggested in this study would be useful reference data for the design of a multi-GNSS receiver in the future.