• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권11호
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• pp.5394-5409
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• 2019

The paper investigates a novel detector receiver with Kalman channel information estimator and iterative channel response equalization for MIMO (multi-input multi-output) OFDM (orthogonal frequency division multiplexing) communication systems in fast multipath fading environments. The performances of the existing linear equalizers (LE) are not good enough over most fast fading multipath channels. The existing adaptive equalizer with decision feedback structure (ADFE) can improve the performance of LE. But error-propagation effect seriously degrades the system performance of the ADFE, especially when operated in fast multipath fading environments. By considering the Kalman channel impulse response estimation for the fast fading multipath channels based on CE-BEM (complex exponential basis expansion) model, the paper proposes the iterative receiver with soft decision feedback equalization (SDFE) structure in the fast multipath fading environments. The proposed SDFE detector receiver combats the error-propagation effect for fast multipath fading channels and outperform the existing LE and ADFE. We demonstrate several simulations to confirm the ability of the proposed iterative receiver over the existing receivers.

• 한국음향학회지
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• 제21권8호
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• pp.671-678
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• 2002

천해에서 적용 가능한 고주파 단상태 잔향음 모델 (HYREV: HanYang Univ. REVerberation model)을 개발하였다. 천해의 잔향음은 해수면, 해저면의 산란특성에 의해 영향을 크게 받기 때문에 경계면 산란의 정확한 산출이 가능한 잔향음 모델 개발이 필요하다. 본 모델에서는 고유음선 (eigenray) 계산을 통하여 음원과 산란체까지의 도달시간과 전달손실을 계산하였으며 경계면 산란 예측은 복합 거칠기 (composite roughness) 모델을 이용하였다. 모델의 검증을 위하여 GSM (generic sonar model) 잔향음 모의 신호 및 실측 잔향음 신호와 비교하였으며 비교 결과 GSM보다 HYREV 모델이 천해 잔향음 예측에 적합함을 확인할 수 있었다.