http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Adaptive Complex Interpolator for Channel Estimation in Pilot-Aided OFDM System
Liu, Guanghui,Zeng, Liaoyuan,Li, Hongliang,Xu, Linfeng,Wang, Zhengning The Korea Institute of Information and Commucation 2013 Journal of communications and networks Vol.15 No.5
In an orthogonal frequency division multiplexing system, conventional interpolation techniques cannot correctly balance performance and overhead when estimating dynamic long-delay channels in single frequency networks (SFNs). In this study, classical filter analysis and design methods are employed to derive a complex interpolator for maximizing the resistible echo delay in a channel estimator on the basis of the correlation between frequency domain interpolating and time domain windowing. The coefficient computation of the complex interpolator requires a key parameter, i.e., channel length, which is obtained in the frequency domain with a tentative estimation scheme having low implementation complexity. The proposed complex adaptive interpolator is verified in a simulated digital video broadcasting for terrestrial/handheld receiver. The simulation results indicate that the designed channel estimator can not only handle SFN echoes with more than $200{\mu}s$ delay but also achieve a bit-error rate performance close to the optimum minimum mean square error method, which significantly outperforms conventional channel estimation methods, while preserving a low implementation cost in a short-delay channel.
Robust CFO Acquisition in PN-Padded OFDM Systems
Guanghui Liu,Liaoyuan Zeng,Hongliang Li,Linfeng Xu,ZhengningWang 한국전자통신연구원 2013 ETRI Journal Vol.35 No.4
As an alternative to the traditional pilot-aided orthogonal frequency division multiplexing (OFDM), the time-domain pseudonoise (PN)-padded OFDM provides a higher spectral efficiency. However, the carrier frequency offset (CFO) attenuates peaks of the conventional PN correlation output, which limits the CFO estimation range of the OFDM synchronizer. An improved correlation is proposed in this letter to remove the CFO-induced amplitude attenuation of correlation peaks. For a synchronizer adopting the designed correlator, a larger range of CFO acquisition is obtained through using wider correlation windows with a smaller interval between them. The proposed method of CFO acquisition is verified in a digital terrestrial multimedia broadcast receiver, in which the synchronizer is able to acquire CFOs up to ±320 kHz in the DVB-T F1 channel. Furthermore, the acquisition range can be expanded in more favorable channels.
Adaptive Complex Interpolator for Channel Estimation in Pilot-Aided OFDM System
Guanghui Liu,Liaoyuan Zeng,Hongliang Li,Linfeng Xu,ZhengningWang 한국통신학회 2013 Journal of communications and networks Vol.15 No.5
In an orthogonal frequency division multiplexing system,conventional interpolation techniques cannot correctly balanceperformance and overhead when estimating dynamic longdelaychannels in single frequency networks (SFNs). In this study,classical filter analysis and design methods are employed to derivea complex interpolator for maximizing the resistible echo delay in achannel estimator on the basis of the correlation between frequencydomain interpolating and time domain windowing. The coefficientcomputation of the complex interpolator requires a key parameter,i.e., channel length, which is obtained in the frequency domain witha tentative estimation scheme having low implementation complexity. The proposed complex adaptive interpolator is verified in asimulated digital video broadcasting for terrestrial/handheld receiver. The simulation results indicate that the designed channelestimator can not only handle SFN echoes with more than 200 µsdelay but also achieve a bit-error rate performance close to the optimumminimum mean square error method, which significantlyoutperforms conventional channel estimation methods, while preservinga low implementation cost in a short-delay channel.