This paper investigates pilot-symbol-aided channel estimation/prediction for Multiple-Input Multiple-Output (MIMO) systems in fast fading environments. We first derive the design criteria of the optimal pilot blocks f...This paper investigates pilot-symbol-aided channel estimation/prediction for Multiple-Input Multiple-Output (MIMO) systems in fast fading environments. We first derive the design criteria of the optimal pilot blocks for energy, power and bandwidth-limited systems, respectively. Then two low-complexity channel estimation schemes are provided. Finally, we present a robust Minimum Mean Square Error (MMSE) channel estimator based on channel time correlation. Simulation shows the proposed MMSE estimator is considerably insensitive to channel statistics and significantly outperforms the traditional estimators with a low additional complexity in fast fading environments. By simply adjusting some parameters, the MMSE estimator can work as an estimator and a predictor simultaneously.展开更多
We present a new synchronization scheme for Orthogonal Frequency-Division Multiplexing (OFDM) systems. In this scheme, time synchronization and carrier frequency offset correction can be performed in one identical tra...We present a new synchronization scheme for Orthogonal Frequency-Division Multiplexing (OFDM) systems. In this scheme, time synchronization and carrier frequency offset correction can be performed in one identical training symbol. Time synchronization algorithm is robust and simple operated, and its performance is independent of the carrier frequency offset. We derive the theoretical variance error for our time synchronization algorithm in AWGN channel. We also derive the performance lower bound of our frequency offset correction algorithm. The frequency offset correction algorithm is high accuracy and its performance will degrade very little under multipath fading environment.展开更多
The ISM band at 2.4 GHz has mostly been used or planned for indoor systems.This band is also attractive for outdoor systems owing to the ease of the system deployment, as nofrequency licenses are required. In this pap...The ISM band at 2.4 GHz has mostly been used or planned for indoor systems.This band is also attractive for outdoor systems owing to the ease of the system deployment, as nofrequency licenses are required. In this paper, a multiple successive internal multireflection modelis used to estimate the complex electric permittivity at 2.4 GHz band. To obtain the data,measurements are performed at 160 MHz bandwidth centered about 2. 4 GHz using a vector networkanalyzer, which provides information about the amplitude and phase of transmission coefficient.Several samples of each material are measured and the results vary from sample to sample. It hasalso been found that some obstacles have polarization behaviour.展开更多
文摘This paper investigates pilot-symbol-aided channel estimation/prediction for Multiple-Input Multiple-Output (MIMO) systems in fast fading environments. We first derive the design criteria of the optimal pilot blocks for energy, power and bandwidth-limited systems, respectively. Then two low-complexity channel estimation schemes are provided. Finally, we present a robust Minimum Mean Square Error (MMSE) channel estimator based on channel time correlation. Simulation shows the proposed MMSE estimator is considerably insensitive to channel statistics and significantly outperforms the traditional estimators with a low additional complexity in fast fading environments. By simply adjusting some parameters, the MMSE estimator can work as an estimator and a predictor simultaneously.
文摘We present a new synchronization scheme for Orthogonal Frequency-Division Multiplexing (OFDM) systems. In this scheme, time synchronization and carrier frequency offset correction can be performed in one identical training symbol. Time synchronization algorithm is robust and simple operated, and its performance is independent of the carrier frequency offset. We derive the theoretical variance error for our time synchronization algorithm in AWGN channel. We also derive the performance lower bound of our frequency offset correction algorithm. The frequency offset correction algorithm is high accuracy and its performance will degrade very little under multipath fading environment.
文摘The ISM band at 2.4 GHz has mostly been used or planned for indoor systems.This band is also attractive for outdoor systems owing to the ease of the system deployment, as nofrequency licenses are required. In this paper, a multiple successive internal multireflection modelis used to estimate the complex electric permittivity at 2.4 GHz band. To obtain the data,measurements are performed at 160 MHz bandwidth centered about 2. 4 GHz using a vector networkanalyzer, which provides information about the amplitude and phase of transmission coefficient.Several samples of each material are measured and the results vary from sample to sample. It hasalso been found that some obstacles have polarization behaviour.
