Blind Channel Estimation in Orthogonally Coded MIMO-OFDM Systems: A Semidefinite Relaxation Approach

Sarmadi, Nima; Shahbazpanahi, Shahram; Gershman, A.B.

doi:10.1109/tsp.2009.2016887

Cited by 36 publications

(13 citation statements)

References 49 publications

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“…In this case, the signal model in (5) reduces to (12) where h CLNt and w CNcT are respectively the channel vector and noise vector for Nr = 1. The noncoherent ML decoder in (10) (taking into account the pilot placement in (18)) reduces to (13) We first analyze the pair-wise error probability (PEP) of the noncoherent ML decoder (22), that is, the probability that the noncoherent ML decoder mistakes the true transmitted codeword ¯c ∈ C for a distinct codeword ˆc ∈ C. Let dfree be the free Hamming distance (i.e., the minimum Hamming distance) of the …”

Section: B Noncoherent Diversity Analysismentioning

confidence: 99%

“…While it is possible to extend the works in [9], [10] to coded OSTBC-OFDM by considering each OFDM subcarrier as an individual flat-fading channel, such natural extension requires the channel to remain static over a large number of OFDM blocks. Similarly, many of the blind channel estimation methods in [12], [13] for uncoded OSTBCOFDM also require the channel to remain unchanged for several OSTBC-OFDM blocks. These approaches are therefore suitable for slow or perhaps moderately fast fading channels.…”

Section: Introductionmentioning

confidence: 99%

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Diversity Analysis for Relay-Assisted Distributed BICM-OSTBCOFDM System

Dhanasekar¹,

Revathi²

2014

IOSRJEN

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-Maximum spatial-frequency diversity can be achieve by combining bit-interleaved coded modulation (BICM), orthogonal space-time block coding (OSTBC) and orthogonal frequency division multiplexing (OFDM) in frequency selective multi-path fading channels, provided that perfect channel state information (CSI) is available to the receiver. In view of the fact that perfect CSI can be obtained only if a sufficient amount of resource is allocated for training or pilot data, this paper investigates DF relay based technique for the distributed BICM-OSTBC-OFDM system. Our focus is mainly on noncoherent diversity analysis. We study a class of carefully designed transmission schemes, called perfect channel identifiability (PCI) achieving schemes, and show that they can exhibit good diversity performance. Specifically, we present a worst-case diversity analysis framework to show that PCI-achieving schemes can achieve the maximum noncoherent spatial-frequency diversity of distributed BICM-OSTBC-OFDM. Simulation results are presented to confirm our theoretical claims and show that the proposed noncoherent schemes can exhibit near-coherent performance.

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Section: B Noncoherent Diversity Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Diversity Analysis for Relay-Assisted Distributed BICM-OSTBCOFDM System

Dhanasekar¹,

Revathi²

2014

IOSRJEN

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“…The subcarrier-wise approach may suffer from a prohibitively high computational complexity when the number of subcarriers is large. A coherent approach was proposed in [5] for blind channel estimation for orthogonally coded MIMO-OFDM systems with more than 2 transmit antennas. Because the approach is based on convex optimization and amounts to solving a semidefinite program (SDP), its computational cost may be rather high.…”

Section: Introductionmentioning

confidence: 99%

New subspace-based blind channel estimation for orthogonally coded MIMO-OFDM systems

Jiang

Lin

Phoong

2014

2014 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)

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Two novel subspace-based blind channel estimation methods for orthogonally coded multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems with more than two transmit antennas are proposed in this paper. The proposed methods exploit the null space induced by the orthogonal space-time block codes (OSTBC). They can be applied to systems with one or more receive antennas. Simulation results show that accurate estimates can be obtained.

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“…Moreover, it may suffer from a high computational complexity when the symbol vector size is large. The approach of [6] which is based on convex optimization does not provide any closed-form solution for channel estimation and amounts to solving a semidefinite programming (SDP) problem. Therefore, its computational cost may be considerably high.…”

Section: Introductionmentioning

confidence: 99%

“…Also, in contrast to the technique of [5], our method is independent of the transmitted signal constellation and applicable to more than one data block. Moreover, proposed technique amounts to solving eigenvector problem and, therefore, is closed-form and its complexity is lower than that of the approach of [6]. At the same time, unlike the methods of [7]- [9], the proposed technique is able to systematically exploit the knowledge of the transmitted data covariance matrix to resolve the non-scalar ambiguities associated to channel estimation in the case of the rotatable codes and MISO system configurations.…”

Section: Introductionmentioning

confidence: 99%

Closed-form blind channel estimation in orthogonally coded MIMO-OFDM systems: A simple strategy to resolve non-scalar ambiguities

Sarmadi

Pesavento

2011

2011 IEEE 12th International Workshop on Signal Processing Advances in Wireless Communications

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We consider blind channel estimation in multiple-input multipleoutput orthogonal frequency-division multiplexing (MIMO-OFDM) systems with orthogonal space-time block code (OSTBC). We introduce a novel weighted covariance matrix of the received data which exploits all redundancies contained in the code. Based on the orthogonality properties of OSTBCs, we further show that a low-rank subspace mode applies to this matrix. Assuming a delay spread over the wireless channel smaller than the OFDM symbol duration, we prove that the corresponding signal subspace in time-domain collapses to a single principal eigenvector from which the channel taps can be uniquely determined. Unlike to previous methods, which suffer from ambiguities, for example, in the case of rotatable OSTBCs, our weighted covariance approach allows to resolve all non-scalar ambiguities provided that a specific transmitted symbol exhibits a higher power than the remaining symbols.

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Blind Channel Estimation in Orthogonally Coded MIMO-OFDM Systems: A Semidefinite Relaxation Approach

Cited by 36 publications

References 49 publications

Diversity Analysis for Relay-Assisted Distributed BICM-OSTBCOFDM System

Diversity Analysis for Relay-Assisted Distributed BICM-OSTBCOFDM System

New subspace-based blind channel estimation for orthogonally coded MIMO-OFDM systems

Closed-form blind channel estimation in orthogonally coded MIMO-OFDM systems: A simple strategy to resolve non-scalar ambiguities

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