• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.2
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• pp.154-161
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• 2013

This paper presents the signal-to-interference plus noise ratio (SINR) estimation of IEEE 802.16m WirelessMAN-Advanced mobile station with simulation and implementation 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 efficient method of estimating SINR with A-Preambles, by measuring noise power from PA-preamble and measuring interference power and signal power from SA-preamble. The proposed SINR measurement block contains important features such as subcarrier phase rotation elimination and simplified dB transform. The result of this paper is integrated to ETRI's IEEE 802.16m test mobile station, used for decision of adaptive-modulation-and-coding (AMC) and hand-over. It showed good measurement performance in simulation and unified system link test also.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.2
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• pp.207-213
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• 2024

This paper examines the frame boundary detection performance for a satellite navigation augmentation signal orthogonally modulated with Hadamard code to determine the number of message preamble bits. Simulation results show that, even in weak signal environments, designing the message preamble with 32 bits is recommended for achieving stable frame boundary detection.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.1
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• pp.39-46
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• 2017

In this paper, we propose an integer frequency offset estimation and compensation method based on PLC preamble correlation in DOCSIS 3.1 Downstream system. The proposed method determines the PLC preamble subcarrier location recovered from PLC data and the one obtained from PLC preamble correlation. We showed the performance of PLC preamble detection in the received signal through the maximum value detection of PLC preamble correlation. Thus we can estimate and compensate for the integer frequency offset by computing the difference of PLC subcarrier locations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1A
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• pp.65-76
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• 2004

In this paper, a novel preamble structure, including a synchronization preamble and a cell search preamble, is proposed for OFDM-based cellular systems. An efficient algorithm for downlink synchronization and cell searching using the preamble is also proposed. The synchronization process includes the initial symbol timing estimation using continuously, or at least, periodically transmitted downlink signal, frame synchronization, the fine symbol timing estimation, and the frequency offset estimation using the synchronization preamble, and the cell identification using the cell searching preamble. Performance of each synchronization and cell searching step is analyzed and the analytic results including the overall performance of the synchronization and cell searching are verified by computer simulation. It is shown that the proposed preamble with the corresponding synchronization and cell searching algorithm can provide very robust synchronization and cell searching capability even in bad cellular environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.8B
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• pp.1436-1444
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• 2000

In this paper, we propose the joint carrier and symbol timing recovery algorithm using repetitive preamble and differential detection for burst modem. The proposed algorithm can estimate the frequency offset and the symbol timing error regardless of the amount of frequency offset, with a high accuracy, even using very short preamble and at low SNR values. The algorithms for continuous phase frequency shift keying (CPFSK) and phase shift keying (PSK) types are developed. Through computer simulations, we compare the proposed algorithm with the existing algorithms on the estimation accuracy in terms of the preamble length, and analyze those bit error rate(BER) performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7C
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• pp.706-714
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• 2009

In this paper, we proposed a burst mode AGC loop and preamble detector applicable for VDL(VHF Digital Link) mode-2 using D8PSK modulation scheme and the performance analysis of proposed schemes is described. Generally the AGC scheme can be divided into two types, continuos and burst mode AGC. The continuos mode is performed well only with an analog feedback AGC loop. But the analog feedback AGC loop is not suitable for burst mode since its gain lock time is more than preamble duration, which causes the preamble detector misses preamble. Hence a fast digital AGC loop is required for burst mode. Also the AGC loop has to be designed with full gain during idle time to detect bursts although the signal level is very low. If the time to acquire gain lock is slow, the preamble detector fail to detect burst due to saturation of a lot of preamble samples. The receiver performance might be down even if the burst was detected because the preamble is used to estimate several parameters need to demodulation at receiver. In this paper we analysed relationships between the AGC loop and preamble detector. we present an AGC loop and preamble detector in burst mode.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11A
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• pp.1848-1857
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• 2001

This paper proposes the ETEO and MTEO burst signal detector based on TEO algorithm. These algorithms must be used after STR and AGC operation, but are not related to phase and frequency offset. ETEO algorithm is extended version of original TEO, and MTEO algorithm is proposed for improving the output characteristics of ETEO. Also, modified ETEO and MTEO algorithm are proposed for detection of PREAMBLE64. Optimal threshold value is determined and miss and false alarm probability and FER performance are evaluated by computer simulation. Finally, this paper proposes MTEO algorithm with M=3 to guarantee the Performance that FER is less than 10$\^$-2/.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.1
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• pp.60-63
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• 2009

In this paper, Designed and implemented about module that generate division signal for uplink section and downlink section for controlling Tx/Rx antenna of 2.3-2.7GHz WiMAX TDD repeater. It is consisted of RF block and Baseband block, and because function of this module is that synchronize with WiMAX signal and create division signal for uplink section and downlink section, this module was designed only received path. And because of manufacturing of most RF block by one chip, this module could minimize area. And in baseband block, used the WiMAX Modem to detect Preamble and DL-MAP information of WiMAX signal. This design can process about 2.3-2.7GHz WiMAX.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.15-18
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• 2004

A high data rate Wireless Personal Area Networks (WPAN) system is a hot issue in wireless communication communities and being standardized. Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM) is one of the candidates for WPAN standard. In this paper, we discuss the PLCP (Physical Layer Convergence Protocol) structure for MB-OFDM. Also we evaluate the performance of two signal detection algorithms, which are the method of cross-correlation with the original preamble and the signed preamble. The latter has a low complexity with a little degradation.