Adaptive Orthogonal Beamforming for the Mimo Broadcast Channel

Duplicy, Jonathan; Palomar, Daniel P.; Vandendorpe, Luc

doi:10.1109/camsap.2007.4497969

Cited by 13 publications

(27 citation statements)

References 5 publications

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“…As shown in (12), SINR kn is more likely to decrease with n increases. Thus, the user with a small n (at high layer) enjoys a higher SINR thanks to the MOBF, where a high QoS requirement could be guaranteed.…”

Section: International Journal Of Distributed Sensor Networkmentioning

confidence: 89%

“…According to (12) and (14), when γ k is sufficiently large, the SINR-based user selection criterion is approximately identical to choose the user who has the smallest sum of ODs. Hence, the resulting selection scheme is regarded as the orthogonal deficiency sequential (ODS) user selection, which is summarized as follows.…”

Section: Od-based User Selectionmentioning

confidence: 99%

“…Since it is not easy to find the PDF and CDF of SINR kn in (8), we consider SIR as the approximation of SINR in (12) and the upper bound in (13). Letting Γ be the threshold SINR, the outage probability of SINR in (12) for a random user k ∈ A n is approximately obtained as…”

Section: Sinr Outage Probabilitymentioning

confidence: 99%

“…However, good performance of ZFBF cannot be guaranteed with limited number of users and low signal-to-noise ratio (SNR) regime. Thus, orthogonal BF (OBF) is proposed in [11] and further developed in [12] to improve the performance, while a hybrid scheme is studied in [13] to achieve promising performance in various scenarios. In [14], the probability density function (PDF) expressions for the scheduled users and closed-form expression of the first and second scheduled users are derived to theoretically analyze the performance of OBF.…”

Section: Introductionmentioning

confidence: 99%

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Multilayer Orthogonal Beamforming for Priority-Guaranteed Wireless Communications

Xie

Zhang

Bai

2012

International Journal of Distributed Sensor Networks

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To utilize the benefits of cellular systems, wireless machine-to-machine (M2M) communications over cellular systems are being widely considered. In order to support efficient spectrum sharing between M2M devices and normal mobile users, in the paper, we propose a multilayer orthogonal beamforming (MOBF) scheme for M2M communications over orthogonal frequency division multiple access (OFDMA-) based cellular systems. Using MOBF, each subcarrier in OFDMA systems could be efficiently reused by both normal mobile users and machine-type devices which are organized into multiple virtual layers. The users located in higher layers (e.g., mobile users) are not to be interfered by those in lower layers (e.g., machine devices). To improve the performance, the orthogonal deficiency (OD-) based user selection is carried out, where the intralayer fairness and quasimaximal performance can be guaranteed, simultaneously. Moreover, the signal-to-interference plus noise ratio (SINR) is investigated to measure the performance lower bound of different layers. It is demonstrated by both theoretical and numerical results that the proposed approach provides a stable SINR performance for each layer, that is, the interference free ability from lower level layers.

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Section: International Journal Of Distributed Sensor Networkmentioning

confidence: 89%

Section: Od-based User Selectionmentioning

confidence: 99%

Section: Sinr Outage Probabilitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Multilayer Orthogonal Beamforming for Priority-Guaranteed Wireless Communications

Xie

Zhang

Bai

2012

International Journal of Distributed Sensor Networks

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“…In order to address the user scheduling and BF weight vector design problems jointly at relatively low complexity, a number of suboptimal BF methods combined with user scheduling have been proposed [2]- [6] and shown to achieve a significant portion of DPC sum capacity [3]- [6]. A semiorthogonal user selection algorithm has been combined with zero-forcing beamforming (ZFBF) in [3] and has been shown to asymptotically attain the same sum rate as that of DPC.…”

Section: Introductionmentioning

confidence: 99%

Performance Analysis of Orthogonal Beamforming with User Selection in MIMO Broadcast Channels

Özyurt

Torlak

2011

2011 IEEE Global Telecommunications Conference - GLOBECOM 2011

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This work considers the problem of multiuser transmission in a downlink transmission system where a transmitter with multiantenna elements sends information to a set of scheduled users with each having a single antenna. We investigate the sum rate performance of an orthogonal beamforming (OBF) scheme called adaptive OBF, which is a suboptimal lowcomplexity alternative to the capacity-achieving dirty paper coding approach. We develop a simple order statistics framework to evaluate the probability density functions (pdfs) of the scheduled users' signal-to-interference plus noise ratio (SINR) values based on the knowledge of channel statistics and selection procedure. In particular, the pdf expressions for first and second scheduled users' SINR values are obtained in closed-form. The analysis is verified by numerical results.Index Terms-Broadcast channel, multiple-input single-output, orthogonal beamforming, sum rate.

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Successive orthogonal beamforming for cooperative multi‐point downlinks

Bai

Chen

et al. 2013

IET Communications

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This study considers successive orthogonal beamforming (SOBF) for multicell downlink transmissions. A group of base stations (BSs) are in cooperation for effective downlink transmissions to cell-edge users, which is usually referred to as cooperative multi-point. As the number of cell-edge users is small and varying, conventional beamforming schemes, for example, zero-forcing beamforming (ZFBF), are not suitable for the multicell scenario. In the SOBF scheme considered here, the beamforming vectors are found in a successive manner when a new user comes in, so that the beamforming vectors of the existing users remain unchanged. With limited channel state information at the group of BSs, a new successive beam allocation (SBA) scheme is proposed for SOBF. In SBA, the candidate beams are broadcasted to all the users through downlink before the index of the best beam is sent back to the BS by each user. The sum rate performance of a system with two users is studied analytically. The numerical results are presented to show that the proposed SOBF with SBA outperforms ZFBF with conventional feedback strategy.

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Adaptive Orthogonal Beamforming for the Mimo Broadcast Channel

Cited by 13 publications

References 5 publications

Multilayer Orthogonal Beamforming for Priority-Guaranteed Wireless Communications

Multilayer Orthogonal Beamforming for Priority-Guaranteed Wireless Communications

Performance Analysis of Orthogonal Beamforming with User Selection in MIMO Broadcast Channels

Successive orthogonal beamforming for cooperative multi‐point downlinks

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