On perfect channel identifiability of semiblind ML detection of orthogonal space-time block coded OFDM

This paper considers maximum-likelihood (ML) detection of orthogonal space-time block coded OFDM (OSTBC-OFDM) systems without channel state information. Our previous work has shown an interesting identi ability result, that the whole time-domain channel can be uniquely identi ed by only having one subchannel to transmit pilots. However, this identi ability is in a probability-one sense, under some mild assumptions on the channel statistics. In this paper we establish a "perfect" channel identi ability (PCI) condition under which the channel is always uniquely identi able. It is shown that PCI can be achieved by judiciously applying the so-called non-intersecting subspace OSTBCs. The resultant PCI achieving scheme has its number of pilots larger than that used in the previous probability-one identi ability achieving scheme, but smaller than that required in conventional pilot-aided channel estimation. Simulation results are presented to show that the proposed scheme can provi...

• Type: Journal
• Year: 2009
• Where: ICASSP
• Authors: Tsung-Hui Chang, Wing-Kin Ma, Chuan-Yuan Huang, Chong-Yung Chi
• Keywords: Channel State Information, ICASSP 2009, Identi Ability, Orthogonal Space-Time Block, Signal Processing