• Title/Summary/Keyword: effective carrier-to-noise power ratio

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Cramer-Rao Lower Bound of Effective Carrier-to-noise Power Ratio Estimation for a GPS L1 C/A Signal under Band-limited White Noise Jamming Environments (대역제한 백색잡음 재밍환경에서 GPS L1 C/A 신호를 위한 유효 반송파 대 잡음 전력비 추정치의 CRLB)

  • Yoo, Seungsoo;Yeom, Dong-Jin;Jee, Gyu-In;Kim, Sun Yong
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.8
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    • pp.890-894
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    • 2014
  • In this paper, we derive the CRLB (Cramer-Rao Lower Bound) of effective carrier-to-noise power ratio ($C/N_0$) estimation for a GPS (Global Positioning System) L1 C/A (Coarse/Acquisition) signal under band-limited white noise jamming environments. The quality of a received GPS signal is commonly described in terms of its $C/N_0$, implying that the noise is white and thus can be described by scalar noise density. However, if some intentional interference is received to a victim GPS receiver, then the $C/N_0$ is no longer the efficacious performance indicator. The correct and straightforward measurement to analyze the receiving situation is the effective $C/N_0$. In this paper, we consider a band-limited white noise jamming whose bandwidth is 2MHz and is the same as one of the first null-to-null bandwidth of the GPS L1 C/A signal.

Compensation of Phase Noise and IQ Imbalance in the OFDM Communication System of DFT Spreading Method (DFT 확산 방식의 OFDM 통신 시스템에서 위상잡음과 직교 불균형 보상)

  • Ryu, Sang-Burm;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.1
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    • pp.21-28
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    • 2009
  • DFT-spread OFDM(Discrete Fourier Transform-Spread Orthogonal Frequency Division Multiplexing) is very effective for solving the PAPR(Peak-to-Average Power Ratio) problem. Therefore, the SC-FDMA(Single Carrier-Frequency Division Multiple Access) which is basically same to the DFT spread OFDM was adopted as the uplink standard of the 3GPP LTE ($3^{rd}$ Generation Partnership Project Long Term Evolution). Unlike the ordinary OFDM system, the SC-FDMA using DFT spreading method is vulnerable to the ICI(Inter-Carrier Interference) problem caused by the phase noise and IQ(In-phase/Quadrature) imbalance and effected FDE(Frequency Domain Equalizer). In this paper, the ICI effects from the phase noise and IQ imbalance which can be problems in uplink transmission are analyzed according the back-off level of HPA. Next, we propose the equalizer algorithm to remove the ICI effects. This proposed equalizer based on the FDE can be considered as up-graded and improved version of PNS(Phase Noise Suppression) algorithm. This proposed equalizer effectively compensates the ICI resulting from the phase noise and IQ imbalance. Finally, through the computer simulation, it can be shown that about SNR=14 dB is required for the $BER=10^{-4}$ after ICI compensation when the back-off is 4.5 dB, $\varepsilon=0.005$, $\phi=5^{\circ}$, and $pn=0.06\;rad^2$.

Single-Fiber Bidirectional Transmission System Using Base Station Without Light Sources (광원이 없는 Base Station을 이용한 단일 광섬유 양방향 전송 시스템)

  • 전금수;정용채;임명섭;반재경
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.5A
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    • pp.323-332
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    • 2003
  • We have proposed and implemented a novel cost-effective optical subcarrier mutiplexing transceiver for base station without light sources in which optical signal can be transmitted bidirectionally over a single optical fiber. Modulated optical signal is retransmitted from the base station to the central office using a ring-type base station which consists of a circulator and an Mach-Zehnder modulator, where the optical source is supplied from the central office. In order to investigate the feasibility of the proposed base station without light sources, we have measured adjacent channel power ratio and carrier to noise ratio by transmitting the IS-95 CDMA signal and 14 tones carrier signal bidirectionally through the system.

A Design of SINR Measurement Unit for IEEE 802.16m (IEEE 802.16m 시스템의 SINR 측정기의 설계)

  • Kim, Jun-Woo;Park, Youn-Ok;Kim, Whan-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.12A
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    • pp.1097-1104
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    • 2010
  • This paper presents the signal-to-noise ratio (SNR) and signal-to-interference plus noise ratio (SINR) estimation based on A-Preamble of IEEE 802.16m IMT-Advanced WiMax system with simulation results. The downlink signal of IEEE 802.16m has two kinds of A-Preambles: the PA-Preamble and the SA-Preamble. This paper proposes the effective method of estimating SNR and SINR with A-Preambles, and also shows that this method can recognize the ICI(Inter-Carrier-Interference) occurrence due to doppler frequency. With the recognition of ICI, the mobile station can save the power by operating 1-tap equalizer in usual cases, and activating ICI mitigation module only when it perceives the ICI occurrence.

Resource scheduling scheme for 5G mmWave CP-OFDM based wireless networks with delay and power allocation optimizations

  • Marcus Vinicius G. Ferreira;Flavio H. T. Vieira;Alisson A. Cardoso
    • ETRI Journal
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    • v.45 no.1
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    • pp.45-59
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    • 2023
  • In this paper, to optimize the average delay and power allocation (PA) for system users, we propose a resource scheduling scheme for wireless networks based on Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) according to the first fifth-generation standards. For delay minimization, we solve a throughput maximization problem that considers CPOFDM systems with carrier aggregation (CA). Regarding PA, we consider an approach that involves maximizing goodput using an effective signal-to-noise ratio. An algorithm for jointly solving delay minimization through computation of required user rates and optimizing the power allocated to users is proposed to compose the resource allocation approach. In wireless network simulations, we consider a scenario with the following capabilities: CA, 256-Quadrature Amplitude Modulation, millimeter waves above 6 GHz, and a radio frame structure with 120 KHz spacing between the subcarriers. The performance of the proposed resource allocation algorithm is evaluated and compared with those of other algorithms from the literature using computational simulations in terms of various Quality of Service parameters, such as the throughput, delay, fairness index, and loss rate.

Performance Analysis of WFMT Modulation System Robust to ICI and Doppler Effect (부반송파간 간섭과 도플러 효과에 강한 WFMT 변조 방식의 성능 분석)

  • Kim, Seon-Ae;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.10
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    • pp.1137-1146
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    • 2008
  • OFDM is very effective for the high speed communication system. However, OFDM has the problems of high PAPR and serious ICI, which is different from the single carrier system. Especially, ICI problem caused by phase noise, Doppler effect and frequency offset is main reason for poor performance since it breaks down the orthogonality between subcarriers in OFDM communication system. Therefore, WFMT modulation scheme is studied and the effect of the carrier frequency offset and phase noise is analyzed. WFMT modulation scheme is based on the wavelet theory and complex filter banks for synthesis and analysis of multichannel signal. WFHT modulation scheme keeps on the advantage of filter banks system and can be easily possible for the implementation of filter banks. In this paper, we compare ISI and ICI distortions of the WFMT and OFDM system due to the carrier frequency offset and phase noise. Also, we analyze the PAPR and BER performances in the HPA and ICI situation caused by the Doppler frequency shift and the frequency offset.