An Iterative Beamforming and Decoding Procedure for Wireless Networks With Uncoordinated Channel Access

Hunziker, Thomas; Aono, Tomoyuki; Ohira, Takashi

doi:10.1109/lcomm.2004.825711

Cited by 6 publications

(3 citation statements)

References 5 publications

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“…Using similar turbo principles, authors in [11,12] present iterative BF and multi-user detection for CDMA based systems. Hunziker et al in [13] propose a Sample Matrix Inversion (SMI) working in conjunction with MAP, working iteratively to mitigate system interference. By employing the iterative BF, authors show effective CCI cancellation in wireless ad-hoc networks with uncoordinated channel access and propose it as an alternative to collision avoidance protocols.…”

Section: Related Work and Algorithm Formulationmentioning

confidence: 99%

Iterative turbo beamforming for orthogonal frequency division multiplexing-based hybrid terrestrial-satellite mobile system

2012

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exhibits a high degree of sensitivity to the pilot sub-carriers. Increasing the number of reference pilots significantly improves BF performance as well as system performance. However, this increase comes at the cost of data throughput which inevitably shrinks due to transmission of additional pilots. Hence an approach where reference signals available to the BF process can be increased without transmitting additional pilots can exhibit superior system performance without compromising throughput.Thus, in this paper we present a novel three-stage Iterative Turbo Beamforming (ITBF) algorithm for an OFDM based Hybrid Terrestrial-Satellite Mobile System which utilises both pilots and data to perform interference mitigation. Data sub-carriers are utilised as virtual reference signals in the BF process. Results show that when compared to non-iterative conventional BF, the proposed ITBF exhibits Bit Error Rate Gain (BERG) of up to 2.5 dB with only one iteration.

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Section: Related Work and Algorithm Formulationmentioning

confidence: 99%

Iterative turbo beamforming for orthogonal frequency division multiplexing-based hybrid terrestrial-satellite mobile system

2012

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“…The recently proposed techniques [15], [16] as well as the 1536-1276/07$25.00 c 2007 IEEE iterative algorithms in the present paper are related to both of these approaches. They are akin to the above mentioned likelihood-maximization methods, however, viewing the CCI as stochastic signals, similar to adaptive beamformers, and estimating the second-order statistics of the CCI rather than the full signals.…”

Section: Introductionmentioning

confidence: 99%

“…In [15], the EM algorithm is employed for channel estimation in the presence of unknown CCI. And [16] proposes an iterative maximum a posteriori decoder incorporating adaptive beamforming.…”

Section: Introductionmentioning

confidence: 99%

Maximum-Likelihood Array Signal Decoding in the Presence of Block-Wise Stationary Cochannel Interference

Hunziker

Bordim

Takeuchi

et al. 2007

IEEE Trans. Wireless Commun.

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We address the demodulation and decoding of array signals in the presence of fluctuating cochannel interference (CCI). The maximum-likelihood decoder is formulated for the case of N receive antennas and stationary, temporally white Gaussian CCI within blocks of K samples, where K ≥ N . The pairwise error probability (PEP) is utilized to quantify the degradation in performance resulting from the absence of side information about the CCI. For pairs of code words that differ over a large number of blocks, an asymptotic PEP performance degradation of 10 log 10 (K/(K −N )) decibels is found.An iterative maximization of the log-likelihood function leads to an alternative suboptimal receiver with reduced complexity, including a block-wise adaptive beamforming via a sample matrix inversion (SMI) and a nearest-neighbor decoding. From the statistics of the spatially filtered signals we find the asymptotic PEP performance, and see that the presence of the desired signal, which is known to adversely affect the output of SMI-based beamformers with small sample support, is gradually mitigated in the iterative procedure.Index Terms-Cochannel interference, maximum-likelihood estimation, adaptive beamforming.

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An iterative beamforming technique for OFDM-based wireless networks with uncoordinated channel access

Hunziker

Aono

Ohira

2004

2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577)

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An Iterative Beamforming and Decoding Procedure for Wireless Networks With Uncoordinated Channel Access

Cited by 6 publications

References 5 publications

Iterative turbo beamforming for orthogonal frequency division multiplexing-based hybrid terrestrial-satellite mobile system

Iterative turbo beamforming for orthogonal frequency division multiplexing-based hybrid terrestrial-satellite mobile system

Maximum-Likelihood Array Signal Decoding in the Presence of Block-Wise Stationary Cochannel Interference

An iterative beamforming technique for OFDM-based wireless networks with uncoordinated channel access

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