Array antenna assisted adaptive modulation scheme for fast fading environment

摘要

Although adaptive modulation is an efficient technique capable of establishing high bit-rate digital transmission in a fading environment, it is sensitive to fast time-variation of the channel state because of difficulty in tracking the channel state. In order to solve this problem, the paper proposes a new array antenna assisted adaptive modulation scheme for fast fading environments. The proposed scheme employs an array antenna-based Doppler spread compensator in order to reduce the time variation. Computer simulation results show that the proposed scheme can drastically improve the bit error rate and throughput performances for the region in which the maximum Doppler frequency, normalized with respect to the packet length, is up to 0.1.