• Title/Summary/Keyword: signal-to-interference power ratio (SIR)

Search Result 36, Processing Time 0.028 seconds

Performance Analysis of Nonlinear Satellite Communication System in the CCI And ACI Interference Channel (간섭채널에서 비선형 위성 통신 시스템의 특성 분석)

  • 박주석;유흥균;김기근;이대일;김도선
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.29 no.2A
    • /
    • pp.166-173
    • /
    • 2004
  • Satellite communication system uses a high non-linear HPA(high power amplifiers) in the earth station and satellite transponder. Therefore, it is important to consider the nonlinear effect of HPA on the communication system. In this paper, we find the variation of power spectrum density by nonlinearity HPA and the change of harmonic component according to IBO (input back-off). When the BPSK is used for satellite communication system, we analyze BER performance including the external co-channel interference (CCI) and the adjacent channel interference (ACI) resulting from the HPA nonlinearity. BER degrades as ACI magnitude grows up when the uplink SNR, uplink SIR (signal to co-channel interference power ratio) and downlink SIR are constant at some level. In case there is only non-linear HPA in the satellite, it is shown that BER considerably depends on the ACI magnitude ACI. When there are two non-linear HPAs in the both earth station and satellite, much BER degradation results from the CCI and ACI.

An Analysis of the Effect of Doppler Spread on Transparent Multi-hop Relays Systems Based on OFDM (OFDM 기반의 트랜스패런트 다중 홉 릴레이 시스템에서 도플러 확산의 영향 분석)

  • Woo, Kyung-Soo;Cho, Yong-Soo
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.44 no.5
    • /
    • pp.40-46
    • /
    • 2007
  • In this paper, the effect of a Doppler Spread caused by a mobile station (MS) is analyzed for transparent mobile multi-hop relays (MMR) systems based on orthogonal frequency division multiplexing (OFDM). The exact expression of interchannel interference (ICI) power and the upper bounds of ICI power are derived for OFDM systems with cooperative MMR or non-coopeartive throughput enhancement (TE) MMR. Also, the exact signal-to-interference ratio (SIR) and its lower bound as well as ICI power and its upper bound, derived in this paper, are evaluated by computer simulation with the OFDM parameter set used for mobile WiMax (WiBro) systems.

The Optimum SIR-Based Downlink Power Control for HAP W-CDMA (HAP W-CDMA 시스템을 위한 SIR 기반의 최적 다운링크 전력 제어)

  • Kang, Young-Heung
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.32 no.6A
    • /
    • pp.642-647
    • /
    • 2007
  • HAP(High Altitude Platform) systems have been proposed due to their unique advantages over terrestrial and satellite systems as the alternative wireless communication system to deliver the third generation IMT-2000 wireless services. It has been required to study for the power control in W-CDMA HAP system as well as the terrestrial mobile system in order to mitigate interference and increase the capacity. In this paper, a new power control has been proposed for HAP system considering the interference profile into the DB(distributed balancing) SIR(signal to interference ratio)-based algorithm which has been considered in terrestrial system, and estimated by the outage performance of the proposed DB algorithm is better remarkably than DBPA(distance-based power allocation) which is proposed for HAP system, and it is the same regardless of the antenna maximum gain and its sidelobe characteristics.

Error Performance Analysis of Trellis Coded QPSK Signal with Reed-Solomon Coding and MRC Diversity Reception in Micro-Cellular System (마이크로 셀룰러 시스템에서 MRC 다이버시티와 Reed-Solomon 부호를 적용한 Trellis Coded QPSK 신호의 오율 해석)

  • 노재성;김영철;박기식;조성언;조성준
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.9 no.4
    • /
    • pp.427-438
    • /
    • 1998
  • The bit error rate(BER) performance of Trellis Coded QPSK signal in the presence of cochannel interference (CCI) and Rician fading is investigated. The trellis coded QPSK system adopts Maximum Ratio Combining (MRC) diversity reception and Reed-Solomon code to enhance system performance. Using the derived error probability equation, the error performance of trellis coded QPSK system has been evaluated and shown in figures to discuss as a function of signal power to noise power ratio (SNR), signal power to interference power ratio(SIR), direct to indirect signal power ratio ($K_R$), the number of diversity branch (M), the frame length of Reed-Solomon code (n), the number of error correction symbol (t), and the number of state of trellis encoder. From the results, we know that proposed system is affected by cochannel interference and fading in microcell environment. Also, BER performance of Trellis Coded QPSK system can be improved as increasing either the power of desired signal or the value of SIR. And the BER floor in microcellular system is caused by the cochannel interference and it occurs at high BER when SIR is low. And Reed-Solomon code (n=15, t=2) is more effective to restrain the affection of CCI and fading than MRC diversity reception (M=2).

  • PDF

Performance Evaluation of Short-Range Communication Home Network in the Presence of Co-Channel Interference (동일채널간섭이 존재하는 홈 네트워크에서 근거리 통신 시스템의 성능 평가)

  • Roh Jae-Sung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2006.05a
    • /
    • pp.555-558
    • /
    • 2006
  • Bluetooth is an open specification technology for short-range wireless connectivity between electronic devices. This paper analyzes the effects of interference on the performance of a Bluetooth system. Two performance criteria used in the study are the signal to interference power ratio (SIR) and the bit error rate (BER) of the bits received. The interference from various sources on the performance of a Bluetooth device is analyzed, and these quantities are plotted against Eb/No and SIR for various channel conditions in figures.

  • PDF

ADAPTIVE SLIDING WINDOW METHOD FOR TURBO CODES IN CDMA CELLULAR SYSTEM WITH POWER CONTROL ERROR

  • Park, Sook-Min;Yoon, Sang-Sic;Kim, Sang-Wu;Lee, Kwyro
    • Proceedings of the IEEK Conference
    • /
    • 2003.07a
    • /
    • pp.565-568
    • /
    • 2003
  • This paper presents a method that can be used to reduce the decoding computational complexity in turbo codes. To reduce the decoding complexity we proposed an adaptive sliding window method which control the learning period of Viterbi sliding window method depending on channel signal to interference ratio (SIR). When received signal to interference ratio (SIR) is relatively high, we can reduce the decoding complexity without a noticeable degradation of BER performance at CDMA cellular system with power control error.

  • PDF

Link Scheduling Method Based on CAZAC Sequence for Device-to-Device Communication (D2D 통신 시스템을 위한 CAZAC 시퀀스 기반 링크 스케줄링 기법)

  • Kang, Wipil;Hwang, Won-Jun;Choi, Hyung-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.38A no.4
    • /
    • pp.325-336
    • /
    • 2013
  • FlashLinQ, one of the typical D2D communication systems developed by Qualcomm, considers a single-tone communication based distributed channel-aware link scheduling method to realize the link scheduling process with low control overheads. However, considering the frequency selective fading effect of practical multi-path channel, the single-tone based SIR estimation causes a critical scheduling error problem because the received single-tone signal has quite different channel gain at each sub-carrier location. In order to overcome this problem, we propose a novel link scheduling method based on CAZAC (Constant Amplitude Zero Auto-Correlation) sequence for D2D communication system. In the proposed method, each link has a unique offset value set for the generation of CAZAC sequences. CAZAC sequences with the cyclic offsets are transmitted using multiple sub-blocks in the entire bandwidth, and then each device can obtain nearly full-band SIR using a good cyclic cross-correlation property of CAZAC sequence.

A Unified Framework for Transmitter Power Control in Cellular Radio Systems

  • Chai, Chin Choy;Lu, Ying;Chew, Yong Huat;Tjhung, Tjeng Thiang
    • ETRI Journal
    • /
    • v.26 no.5
    • /
    • pp.423-431
    • /
    • 2004
  • In earlier works on transmitter power control in cellular radio systems, the problem of whether a signal-to-interference ratio (SIR) threshold is achievable is determined by apparently different rules for homogeneous and heterogeneous SIR systems. In this paper, we present a unified and more universal framework for both cases. We also highlight the conditions under which a given SIR threshold vector for the heterogeneous SIR system is achievable, although so far there is no general solution to this problem.

  • PDF

Performance of SIR-based power control using unused OVSF codes for WCDMA reverse link receiver (미사용 OVSF 부호를 이용한 WCDMA 역방향 링크 수신기의 SIR 기반 전력제어 성능 분석)

  • 이영용;박수진;안재민;임민중;정성현;최형진
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.40 no.7
    • /
    • pp.282-292
    • /
    • 2003
  • In this paper, we evaluate the performance of WCDMA reverse link receiver system with closed loop fast transmit power control (TPC). For fast power control, SIR must be measured precisely. We propose a new SIR measurement algorithm having a simple structure. The proposed algorithm uses unused OVSF code for interference power evaluation. The proposed SIR measurement algorithm is compared to the conventional SIR measurement algorithm in Ref.$^{[1]}$ under closed loop fast TPC. We adopted WMSA channel estimation filter with Κ=2 for mobile radio channel estimation and considered one slot TPC delay. Extensive computer simulation results show that the proposed algorithm using unused OVSF code reduces the required Ε$_{b}$$_{0}$ at the BER of 10$^{-3}$ up to 0.9㏈ and has an improved TPC error performance compared to the conventional algorithm.

Mobile Target Speed Estimation in Urban Environments with Adaptive Power Control (도시환경에서 적응전력제어를 이용한 이동국 속도추정)

  • Lee, Hyeon-Cheol;Lee, Jong Tae;Ryu, Sang Burm;Kang, Eun Su
    • Journal of Satellite, Information and Communications
    • /
    • v.11 no.1
    • /
    • pp.46-50
    • /
    • 2016
  • The adaptive power control of Code Division Multiple Access (CDMA) systems for communications between User Equipments (UEs) with a link-budget based Signal-to-Interference Ratio (SIR) estimate which has distance information is applied to three inner loop power control algorithms. The speed estimation performances of these algorithms with their consecutive Transmit-Power-Control (TPC) ratios are compared to each other, and it is concluded that the speed can be estimated using the TPC ratio information of Consecutive TPC Ratio Step-size Closed Loop Power Control (CS-CLPC) and Fixed Step-size Power Control (FSPC).