• Title, Summary, Keyword: GSM

Search Result 435, Processing Time 0.05 seconds

Implementation of GSM Full Rate vocoder for the GSM mobile modem chip (GSM방식 단말기용 모뎀칩을 위한 GSM Full Rate 보코더 구현)

  • Lee Dong-Won
    • Proceedings of the Acoustical Society of Korea Conference
    • /
    • /
    • pp.9-12
    • /
    • 2001
  • 본 논문에서는 유럽 통신 표준화기구인 ETSI 의 SMGll에서 채택된 GSM Full Rate(FR) 보코더 알고리wma[1]을 Teak DSP Core를 이용하여 실시간 구현하였다. GSM FR 보코더는 유럽에서 사용하는 통신 시스템인 GSM 의 full-rate Traffic Channel(TCH)의 표준 코덱[2]으로서 GSM HR, GSM EFR GSM AMR과 더불어 모뎀칩 내에 장착되는 필수적인 음성 서비스이다. 구현된 GSM FR는 13.05kbps의 비트율을 가지고 있으며, 인코더와 디코더 기능 외에 voice activity detection(VAD)[3]블록과 DTX[4]블록 등의 부가 기능도 구현되어 있다. 구현에 사용된 Teak[5]는 DSP Group 의 16bit고정 소수점 DSP core로서 최대 140MIPS 의 성능을 낼 수 있고 400bits ALU 와 두개의 MAC 이 장착되어 있어 음성 및 채널 부호화기의 실시간 처리에 최적화 되어있다. 구현된 GSM FR 은 인코더와 디코더 부분이 각각 약 235 MIPS 및 1.19MIPS 의 복잡도를 나타내며, 사용된 메모리는 프로그램 ROM 3.9K words, 데이터 ROM(table) 396 words 및 RAM 932words이다.

  • PDF

Effective GSM Interference Cancelling Techniques Using Digital Filter for the Collocated GSM and DVB-H Terminal (GSM과 DVB-H의 복합 단말에서 디지털 필터를 적용한 GSM 간섭 신호 제거 기법)

  • Park, Pyung-Joo;Park, Yong-Woon;Seo, Myung-Hwan;Lee, Byung-Seub
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.20 no.7
    • /
    • pp.589-602
    • /
    • 2009
  • The phenomenon degrading reception performance of DVB broadcasting signal is caused by collocation of plural communication modules in the GSM-900 cellular phone with a built-in DVB-H receiver. This paper offers how to improve performance of the DVB-H receiver by applying digital filter that is using DSP techniques to cancel GSM signal interfering to the DVB-H receiver which is collocated in a single user's GSM terminal. In the demodulation part of the DVB-H receiver, the DVB reception performance can be greatly improved by removing interference components of GSM signal, which is flowed with DVB signal, to the noise cancellation filtering algorithm using difference of characteristics between GSM modulated signal and OFDM signal.

Measurement of Electromagnetic Wave for the Selection of Certification Test Space at GSM Band (GSM 대역용 휴대전화 인증 시험 공간 확보를 위한 전파 환경 측정)

  • Park, Chul-Keun;Min, Kyeong-Sik
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.18 no.9
    • /
    • pp.1030-1038
    • /
    • 2007
  • This paper presents the measurement results of strength of electromagnetic wave for GSM-900/GSM-1800 band which is used in Europe. The Giryong village and Sosan field are selected as candidate regions according to the measurement results in Gijang-gun, Busan. The vertical polarizations is about 12 dBm higher than horizontal polarization at two candidate places, and it is measured 25 dBm lower than urban. The maximum value of measured strength of vertical polarizations in the cellular/GSM-900 bands are -65 dBm at Giryong village and -69 dBm at Sosan field, respectively. The maximum value of measured results of PCS/GSM-1800 bands are -90.5 dBm at Giryong village and -85 dBm at Sosan field, respectively, We confirm that the receiving strength of electromagnetic wave are very weak below -65 dBm at two candidate places and the signals of GSM frequency bands not affect to conversional system, then it is considered as a suitable place for GSM mobile field test.

Coupled-Fed Planar Monopole Antenna for LTE/WWAN Mobile Handset Applications (LTE/WWAN 이동 통신 단말기 응용을 위해 커플드 급전된 평판 모노폴 안테나)

  • Kang, Do-Gu;Lee, Jun-Hyuk;Sung, Young-Je
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.24 no.5
    • /
    • pp.475-483
    • /
    • 2013
  • In this paper, a coupled-fed monopole antenna for LTE/WWAN mobile handset applications is presented. The antenna consists of a monopole, a coupling strip, a feeding pad, a stub, and a shorting strip. The basic resonance of the monopole combines with the resonance formed by the coupling that occurs between the coupling strip and the feeding pad to include LTE700(698~787 MHz), GSM850(824~894 MHz), and GSM900(890~960 MHz) bands. The resonance of the stub combines with the harmonics of the monopole to include GSM1800(1,710~1,880 MHz), GSM1900(1,850~1,990 MHz), and UMTS(1,920~2,170 MHz) bands. Therefore, the proposed antenna is suitable as antenna for hexa-band mobile handset applications, covering LTE700, GSM850, GSM900, GSM1800, GSM1900, and UMTS bands. A stable and omni-directional radiation pattern with reasonable gains is observed within the operating bandwidth.

Real-time Implementation of a GSM-EFR Speech Coder on a 16 Bit Fixed-point DSP (16 비트 고정 소수점 DSP를 이용한 GSM-EFR 음성 부호화기의 실시간 구현)

  • 최민석;변경진;김경수
    • The Journal of the Acoustical Society of Korea
    • /
    • v.19 no.7
    • /
    • pp.42-47
    • /
    • 2000
  • This paper describes a real-time implementation of a GSM-EFR (Global System for Mobil communications Enhanced Full Rate) speech coder using OakDSP core; a 16bit fixed-point Digital Signal Processor (DSP) by DSP Group, Inc. The real-time implemented speech coder required about 24MIPS for computation and 7.06K words and 12.19K words for code and data memory, respectively. The implemented GSM-EFR speech coder passes all of test vectors provided by ETSI (European Telecommunication Standard Institute), and perceptual speech quality measurement using MNB algorithm shows that the quality of the GSM-EFR speech coder is similar to the one of 32kbps ADPCM. The real-time implemented GSM-EFR speech coder which is the highest bit-rate mode of the GSM-AMR speech coder will be used as the basic structure of the GSM-AMR speech coder which is embedded in MODEM ASIC of IMT2000 asynchronous mode mobile station.

  • PDF

GSM 휴대폰의 북미시장 진입을 위한 PTCRB인증시험 개요 및 절차

  • Choe, Du-Jeong;Seong, Gyeong-Mo;Choe, Sang-Ho
    • TTA Journal
    • /
    • /
    • pp.113-119
    • /
    • 2005
  • TTA(한국정보통신기술협회)는 지난 2004년 10월부터 국내 GSM휴대폰 제조업체의 수출진흥을 목적으로 GSM 휴대폰 공인시험소를 구축하여 북미 및 유럽 지역으로 수출되는 GSM휴대폰에 대한 공인인증 시험서비스를 제공하고 있다. 최근에 국내 제조업체들의 북남미 시장 진입이 활발히 이루어지고 있으며 현지 진출을 위한 필수 인증시험 단계인 PTCRB 인증시험 수요가 많아짐에 따라 본 고를 통해 PTCRB 인증시험의 개요 및 인증획득 절차를 소개하고자 한다.

  • PDF

GSM, EDGE, GPRS 시스템의 새로운 표준 암호 알고리즘 분석

  • 홍도원;류희수
    • Review of KIISC
    • /
    • v.12 no.5
    • /
    • pp.70-75
    • /
    • 2002
  • GSM(Global System for Mobile Communications)은 현재 가장 광범위하게 사용되고 있는 디지털 이동 통신의 표준이다. 또한 GSM 표준에서 데이터 전송의 최종 evolution 버전인 EDGE(Enhanced Data for GSM Evolution)와 GSM Phase2+ 개발의 일부분인 GSM 망에서 packet switching을 구현하는 기술인 GPRS(General Packet Radio Service)가 현재 유럽의 정보통신 표준화 기구인 ETSI(European Telecommunications Standards Institute)에 의해 표준화가 진행 중에 있다. GSM 시스템은 사용자 데이터의 기밀성을 보장하기 위한 암호화 알고리즘 A5를 사용하고 있지만 그 취약성이 계속 보고되고 있다. $^{[10,11]}$ 따라서 GSM의 강화된 암호화 알고리즘과 EDGE와 GPRS에서 사용자 데이터를 보호하기 위한 새로운 암호화 알고리즘의 개발이 요구되어왔다. 최근 ETSI의 SAGE(Security Algorithms Group of Experts)는 이러한 목적을 달성할 수 있는 새로운 표준 암호화 알고리즘 A5/3과 GEA3을 개발하였다. $^{[3,4,5,6]}$본 고에서는 GSM, EDGE, GPRS에서의 새로운 표준 암호화 알고리즘 A5/3과 GEA3을 분석하여 정리하고자 한다.

Secure GSM User Authentication Protocol For User Privacy (사용자 프라이버시를 위한 안전한 GSM 사용자인증 프로토콜)

  • Park, Mi-Og;Kim, Chang-Min
    • Journal of the Korea Institute of Information Security & Cryptology
    • /
    • v.16 no.6
    • /
    • pp.157-161
    • /
    • 2006
  • GSM(Global System for Mobile communications) that is the most popular standard for mobile phones, has more than 70% users in the world and the number of users increase continuously. However GSM system has the problem that cannot normally authenticate a user by the exposure of IMSI that is able to uniquely authenticate MS? during the user authentication procedure. In this paper? we provide security enhancement and user privacy by adopting a temporary id and an encryption scheme. Moreover we provide fast user authentication via architecture modification of the conventional GSM user authentication protocol.

An Improved High-Performance Protocol for Security Vulnerability of GSM based on SIM Card (SIM 카드 기반 보안 취약성을 개선한 고성능 GSM 보안 프로토콜)

  • Kim, Hee-Jung;Jeon, Ha-Yong;Lee, Ju-Hwa;Jung, Min-Soo
    • Journal of Korea Multimedia Society
    • /
    • v.10 no.7
    • /
    • pp.902-911
    • /
    • 2007
  • GSM platform is a hugely successful wireless technology and an unprecedented story of global achievement. In less than ten years since the first GSM network was commercially launched, it became the world's leading and fastest growing mobile standard, using over 1 billion GSM subscribers across more than 200 countries of the world. GSM platform evolved into 3th generation mobile communication which includes not only voice call services but also the international roaming and various kinds of the multimedia services. GSM is an essential element techniques a safe data transmission and a personal private protection while support services. However, a crypto algorithm and a secure protocol for a safe data communication using GSM are indicating various kinds of problems. In this paper, we propose a more safer and more efficient authentication protocol in 3th generation network through analysis of GSM security mechanism of 2th/2.5th generation. This security protocol offers enforced security efficiency by using user verification between SIM/ME and reduction of authentication and key agreement step between SIM/ME/AuC.

  • PDF

Software Implementation of GSM Signal Measurements (GSM 신호 측정기의 소프트웨어 구현)

  • Hong, Dae-Ki;Kang, Sung-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.10 no.9
    • /
    • pp.2369-2378
    • /
    • 2009
  • In this paper, we implement measurement functionality for performance measurement of the GSM (Global System for Mobile Communication) terminal by using software. Generally speaking, the receiving algorithms in normal modems cannot be used directly to the measurement system due to the lack of the algorithm accuracy. In this paper, we propose the new receiver algorithm for precise GSM signal measurements. In the receiving algorithm, 2-stage (coarse stage, fine stage) parameters estimation (symbol-timing, frequency offset, carrier phase) scheme is used. To improve the estimation accuracy, we increase the number of the received signal samples by interpolation. The proposed GSM signal measurement algorithm can be used for verifying the hardware measurement system. In addition, the proposed algorithm can be used for the commercial system through code execution speed optimization.