• Title/Summary/Keyword: Channel Sounding

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An Efficient Channel Sounding Method for WPAN System (무선 PAN 시스템을 위한 효율적인 채널 사운딩 기법)

  • Cho, Ju-Phil
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.8 no.3
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    • pp.9-14
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    • 2008
  • In this paper, we propose the channel sounding scheme which is made for ideal communication between some application as well as the short distance of high speed data transmission in MIMO-OFDM system for Wireless PAN. This method is able to perceive the duration of the impulse response through the delaying of power delay profile, modeled a power delay profile which has an attenuate characteristic, and obtained the coefficient of channel response by ML (maximum likelihood). Through the amplitudes, phases and delays associated with each multipath component which were acquired from this channel sounding scheme, we can describe the wave propagation characteristics of channels between the transmitter and receiver so that the receiver could enhance not only the reliability but also the ability of communication link.

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Channel Sounding-based Channel Capacity Measurement of MIMO-OFDM (채널 사운딩 기반의 MIMO-OFDM 채널용량 측정)

  • Park, Bang-Hun;Cho, Ju-Phil;Kim, Seong Kwon;Cha, Jae Sang
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.8 no.5
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    • pp.29-34
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    • 2008
  • In this paper, we propose the channel sounding scheme which improves the reliability and performance of communication link and mitigate the fading effect of channel in MTMO-OFDM system having correlation between Tx and Rx antennas. And we estimate the channel propagation characteristics of channels between the transmitter and receiver with CS scheme by measuring the channel propagation characteristics using sounding signal. Multi agent system models can be used to analyze the path of the system within any time frame. Further, using this proposed method, we can increase the channel capacity by simple calculation in receiver and transmitter and allocate the optimal power by channel information in transmitter. Also, the increment of channel capacity using the prorposed method is induced as the number of antenna is increased. So, we can anticipate the performance improvement with the presented scheme in more complicated Tx and Rx antenna system.

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On new channel estimation method (새로운 채널 추정방법에 관한 연구)

  • 송석일;한영열
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.9A
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    • pp.2240-2247
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    • 1998
  • This paper presents a new method for channel impulse response measurment with a suitably designed binary sounding sequence. This method results in ideal channel estimation using three correlators instead of one. This system complexity can be easily overcome by the present technologies. The class of sounding sequences used in this method are the training sequence for channel impulse response measurment with the zero values of autocorrelation function at all shifts except zero and middle shifts in digital cellular mobile telephone system based on GSM. Computer searches are carried out to find the suitable sounding sequences.

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A Study on the Development of Next Generation Wireless PAN Algorithms with Location Awareness Technique (위치인식기반의 차세대 무선 PAN 알고리즘 개발에 관한 연구)

  • Cho, Juphil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.10
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    • pp.2095-2100
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    • 2012
  • In this paper, we propose the channel sounding scheme which is made for ideal communication between some application as well as the short distance of high speed data transmission in MIMO-OFDM system for Wireless PAN. This method is able to perceive the duration of the impulse response through the delaying of power delay profile, modeled a power delay profile which has an attenuate characteristic, and obtained the coefficient of channel response by ML (maximum likelihood). Through the amplitudes, phases and delays associated with each multipath component which were acquired from this channel sounding scheme, we can describe the wave propagation characteristics of channels between the transmitter and receiver so that the receiver could enhance not only the reliability but also the ability of communication link. Multi agent system models can be used to analyze the path of the system within any time frame. Further, parameter values can be perturbed to examine how the path of the system changes in response to exogenous shocks.

On Performance Evaluation of MIMO Antennas through Channel Sounding (채널사운딩을 통한 다중안테나의 성능평가)

  • Kang, Young-Yun;Cho, Joon-Ho
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.12-13
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    • 2008
  • In this paper, we propose a performance evaluation method for MIMO antennas through channel sounding. From measurement data, the complex channel gain, delay, angle of arrival, and angle of departure of each multipath are estimated. Using these estimates, the MIMO channel impulse response adopting various types of antennas are constructed by replacing the array response vectors, considering antenna patterns and correlation among antenna elements. Comparisons are made in terms of the metrics computed from the impulse responses.

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Fairness-insured Aggressive Sub-channel Allocation and Efficient Power Allocation Algorithms to Optimize the Capacity of an IEEE 802.16e OFDMA/TDD Cellular System

  • Ko, Sang-Jun;Chang, Kyung-Hi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.3 no.4
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    • pp.385-398
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    • 2009
  • This paper aims to find a suitable solution to joint allocation of sub-channel and transmit power for multiple users in an IEEE 802.16e OFDMA/TDD cellular system. We propose the FASA (Fairness insured Aggressive Sub-channel Allocation) algorithm, which is a dynamic channel allocation algorithm that considers all of the users' channel state information conditionally in order to maximize throughput while taking into account fairness. A dynamic power allocation algorithm, i.e., an improved CHC algorithm, is also proposed in combination with the FASA algorithm. It collects the extra downlink transmit power and re-allocates it to other potential users. Simulation results show that the joint allocation scheme with the improved CHC power allocation algorithm provides an additional increase of sector throughput while simultaneously enhancing fairness. Four frames of time delay for CQI feedback and scheduling are considered. Furthermore, by addressing the difference between uplink and downlink scheduling in an IEEE 802.16e OFDMA TDD system, we can employ the uplink channel information directly via channel sounding, resulting in more accurate uplink dynamic resource allocation.

Development and Characterization of Mobile Transceiver for Millimeter-Wave Channel Sounding Measurement (밀리미터파 채널사운딩 측정을 위한 이동형 송수신 장치의 개발과 특성평가)

  • Jonguk Choi
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.24 no.3
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    • pp.35-40
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    • 2024
  • In this paper, the design, implementation, and analysis of a device capable of transmitting and receiving millimeter-wave signals and performing channel sounding measurements in atmospheric conditions at distances of up to approximately 10km outdoors are presented. The device is expected to be instrumental in studying the propagation characteristics of millimeter-wave frequencies. Utilizing data such as received power levels and power delay profiles (PDPs), comparisons with predicted values using path loss, K-factor, and other propagation models are facilitated. The mobile transceiver unit, integrated onto a vehicle platform, allows for flexible adjustment of transmitter and receiver positions, while synchronization issues with distance are mitigated using a rubidium atomic clock. Furthermore, automatic boresight alignment using scanning techniques is employed to locate the main sector of the antenna.

Effect of Doppler Bandwidth on the Performance of Channel Sounding (도플러 대역폭이 채널 추정의 성능에 미치는 영향)

  • Jo, Jun-Ho;Choi, Seyeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.11
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    • pp.5841-5846
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    • 2013
  • In this work, we consider the effect of doppler bandwidth on the performance of channel sounding. We develop the mathematical formulation of the problem and compare the MMSE channel estimator to the simple correlator. Examples of the performance of the MMSE and correlator estimators are presented for the single-input single-output (SISO) case with various values of Doppler bandwidth to assess the impact of time variation. The results show that as the $f_dT$ product increases the performance of both the MMSE and correlator estimates gets worse, and that the performance of the MMSE estimator improves relative to the correlator.We also consider case that the exact statistics of the channel are unknown It is shown that when the mismatch is not too large, the MMSE estimator with mismatch still does better than the simple correlator, but if the mismatch is large, then the correlator can do better.

COMPARISON OF TEMPERATURE DERIVED FROM THE MICROWAVE SOUNDING UNIT AND MONTHLY UPPER AIR DATA.

  • Hwang, Byong-Jun;Kim, So-Hyun;Chung, Hyo-Sang
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.491-495
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    • 1999
  • We compared the satellite observed temperature with the radiosonde observed temperature in the Korean Peninsula. The radiosonde observed data were obtained from four upper air observation stations in the Korean Peninsula from 1981 to 1998, and that was compared with the satellite observed data of the channel-2 and channel-4 of microwave sounding unit(MSU) on board NOAA series of polar-orbiting satellites. The radiosonde data were reconstructed into monthly radiosonde T$_{b}$ using MSU weighting function. The monthly climatology shows radiosonde T$_{b2}$ is higher than MSU T$_{b2}$ in summer. The correlation between MSU T$_{b2}$ and radiosonde T$_{b2}$ is 0.72-0.76 and 0.73-0.81 between MSU T$_{b4}$ and radiosonde T$_{b4}$.

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Capacity Optimization of a 802.16e OPDMA/TDD Cellular System using the Joint Allocation Algorithm of Sub-charmel and Transmit Power - Part II : Sub-channel Allocation in the Uplink Using the Channel Sounding and Initial Transmit Power Decision Algorithm According to the User's Throughput (802.16e OFDMA/TDD 셀룰러 시스템의 성능 최적화를 위한 부채널과 전송전력 결합 할당 알고리즘 - Part II : 상향링크에서 Channel Sounding을 통한 부채널 할당 및 사용자의 수율에 따른 초기전송전력 결정 알고리즘)

  • Ko, Sang-Jun;Chang, Kyung-Hi;Kim, Jae-Hyeong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.9A
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    • pp.888-897
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    • 2007
  • In this paper, we propose an uplink dynamic resource allocation algorithm to increase sector throughput and fairness among users in 802.16e OFDMA TDD system. In uplink, we address the difference between uplink and downlink channel state information in 802.16e OFDMA TDD system. The simulation results show that not only an increment of 10% of sector throughput but higher level of fairness is achieved by round-robin using the FLR and the rate / margin adaptive inner closed-loop power control algorithm. The FLR algorithm determines the number of sub-channels to be allocated to the user according to the user's position. Also, we get 31.8% more sector throughput compared with the round-robin using FLR by FASA algorithm using uplink channel state information. User selection, sub-channel allocation, power allocation algorithms and simulation methodology are mentioned in Part I.