Improved channel estimation over frequency-flat and rapid fading channels

This paper presents the improved technique for channel estimation in mobile radio environments. Conventionally, the symbol-aided techniques use only pilot symbols to estimate the fading process. However, the performance of those schemes will be poor in the severe fading environments. In order to combat with the severe fading channel, the pilot symbol-assisted modulation (PSAM) scheme inserts a more large number of pilot symbols in spite of loss of data throughput, or has to estimate the channel using a great many pilot symbols in spite of more complexity. This paper utilizes not only the channel values in the previous frames but also the channel values in the next frames. By using these channel values besides pilots, the fading estimation with more accuracy can be performed. The simulation results show that the proposed scheme can achieve a considerable performance improvement in the rapid fading environments.