Reliable channel estimation is indispensable for orthogonal frequency-division multiplexing
(OFDM) systems employing coherent detection and adaptive loading in order to achieve
high data rate communications. Several options exist in practical OFDM systems-including
training symbols, cyclic prefix, virtual carriers, pilot tones, and receiver diversity-to facilitate
channel estimation. In this paper, a subspace blind channel estimation method based on
exploiting the presence of virtual carriers is proposed for OFDM systems over a time …

In this paper, a new subspace based blind channel estimation method is proposed for
OFDM systems over a time-dispersive channel. The proposed algorithm exploits the
presence of virtual carriers and eliminates the cyclic prefix; thereby leading to higher
channel utilization than most previously reported cyclic prefix based estimators. A sufficient
condition on the channel identifiability is developed. Comparison with two other cyclic prefix
based subspace methods is presented via computer simulations to support the effectiveness …